Journal articles on the topic 'Direct Interconnection Technique (DIT)'

In this paper, an offshore airborne wind energy (AWE) farm consisting of three non-reversing pumping mode AWE systems is modelled and simulated. The AWE systems employ permanent magnet synchronous generators (PMSG). A direct interconnection technique is developed and implemented for AWE systems. This method is a new approach invented for interconnecting offshore wind turbines with the least number of required offshore-based power electronic converters. The direct interconnection technique can be beneficial in improving the economy and reliability of marine airborne wind energy systems. The performance and interactions of the directly interconnected generators inside the energy farm internal power grid are investigated. The results of the study conducted in this paper, show the directly interconnected AWE systems can exhibit a poor load balance and significant reactive power exchange which must be addressed. Power control strategies for controlling the active and reactive power of the AWE farm are designed, implemented, and promising results are discussed in this paper.

The non-contact C-V technique has been recently gaining interest as a precise, cost and time effective metrology for wide-bandgap semiconductors. Originally focused on dopant measurement, non-contact C-V has been expanding to encompass wide-bandgap surface and interface characterization, including complex reliability issues critical for the future of power devices. In this work, we report progress achieved using a new direct method for determining the flatband voltage, VFB, and capacitance, CFB. Experimental results are presented for n-type oxidized epitaxial 4-H SiC. They demonstrate the approach and the unique self-consistent measurement producing an entire set of pertinent electrical parameters, including the interface trap density, Dit.

With the rapid development of the global economy, the interconnection of power grids has become an objective law and a trend of the power industry development. The implementation of power grid interconnection projects, especially transnational power grid interconnection projects, will bring us substantial benefits. To demonstrate these benefits comprehensively, we designed a comprehensive evaluation index system with multiple international engineering characteristics. The index system takes the influencing factors of economic, social, environmental and technical benefits into account. In order to improve the rigidity and power of weight determination, we proposed the least squares method which combines the order relation method and the factor analysis method. Furthermore, the limitation of the one-way evaluation was effectively overcome by combining TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution), grey relation analysis method and vector projection method. In addition, we adjusted the potential impact of the time on evaluation by using the quadratic weighted algorithm, so that we can dynamically evaluate the comprehensive benefits. Finally, we verified the established index system and evaluation model through an example of eight different investment plans of a transnational high voltage direct current (HVDC) transmission project. Altogether, results from this paper will provide a guidance reference and decision support for the grid corporation to invest in transnational power grid interconnection projects.

An important and interesting parameter of an interconnection network is the number of vertices of a specific distance from a specific vertex. This is known as the surface area or the Whitney number of the second kind. In this paper, we give explicit formulas for the surface areas of the (n, k)-star graphs and the arrangement graphs via the generating function technique. As a direct consequence, these formulas will also provide such explicit formulas for the star graphs, the alternating group graphs and the split-stars since these graphs are related to the (n, k)-star graphs and the arrangement graphs. In addition, we derive the average distances for these graphs.

Nanointerconnection has been selected as a promising method in the post-Moore era to realize device miniaturization and integration. Even with many advances, the existing nanojoining methods still need further developments to meet the three-dimensional nanostructure construction requirements of the next-generation devices. Here, we proposed an efficient silver (Ag)-filled nanotube fabrication method and realized the controllable melting and ultrafine flow of the encapsulated silver at a subfemtogram (0.83 fg/s) level, which presents broad application prospects in the interconnection of materials in the nanometer or even subnanometer. We coated Ag nanowire with polyvinylpyrrolidone (PVP) to obtain core–shell nanostructures instead of the conventional well-established nanotube filling or direct synthesis technique, thus overcoming obstacles such as low filling rate, discontinuous metalcore, and limited filling length. Electromigration and thermal gradient force were figured out as the dominant forces for the controllable flow of molten silver. The conductive amorphous carbonaceous shell formed by pyrolyzing the insulative PVP layer was also verified by energy dispersive spectroscopy (EDS), which enabled the continued outflow of the internal Ag. Finally, a reconfigurable nanointerconnection experiment was implemented, which opens the way for interconnection error correction in the fabrication of nanoelectronic devices.

AbstractHydraulic interconnection of Jomblangan cave (Petung) with other caves and water discharges in Gunungkidul karst area has been investigated using tracer techniques and variationof stable isotopes and hydrochemical data interpretation from water samples near the cave. Many studies related to the interconnections of underground rivers around Gunungkidul Karst area have been conducted, most of them, however, focused on the area around Bribin and Seropan caves. This is because of the development activites of microhydro turbines to lift the water from underground river were still focused around Bribin and Seropan caves. Petung cave, located in the north of Bribin and Seropan caves, was believed to be one of the caves at the upstream river system of Bribin and Seropan, however, there is no evidence yet of the hydraulic interconnection between Petung cave with either Bribin or Seropan caves. The results of tracer technique at the current study showed that there was no hydraulic interconnection between Petung cave with either Bribin and Seropan caves.On the other hand, the study showed an indication of a direct flow from Petung cave to Sriti and Beton springs. The travel times from Petung to Sriti and Beton springs were found to be around 2 and 10 hours, respectively. This finding is also in agreement with the results of chemical and stable isotopes analysis from the research location. AbstrakPenelitian keterhubungan Gua Jomblangan (Petung) dengan gua lainnya dan keluaran air di sekitar daerah karst Gunungkidul telah dilakukan dengan menggunakan teknik perunut dan variasi kandungan isotop stabil serta hidrokimia sampel air di sekitar gua. Penelitian yang berkaitan dengan keterhubungan antara sistim aliran bawah tanah di sekitar daerah karst Gunungkidul telah banyak dilakukan, namun sebagian besar dari penelitian tersebut hanya berpusat pada gua di sekitar Bribin dan Seropan. Hal ini terjadi karena kegiatan pembangunan turbin-turbin mikrohidro untuk mengangkat air dari sungai bawah permukaan tanah masih terfokus di daerah gua Bribin dan Seropan. Gua Petung, yang berada di sebelah utara gua Bribin dan Seropan, dipercaya merupakan salah satu gua yang berada di hulu sistim sungai bawah tanah Bribin dan Seropan, namun, sampai sekarang belum ada bukti keterhubungan hidrolika antara gua Petung dengan gua Bribin maupun dengan gua Seropan.Hasil uji perunut dalam penelitian ini menunjukkan bahwa aliran air bawah tanah di gua Petung tidak berhubungan langsung dengan aliran bawah tanah di gua Bribin maupun di gua Seropan. Sebaliknya, hasil penelitian ini menunjukkan adanya aliran langsung dari gua Petung ke mata air Sriti dan Beton. Waktu tempuh yang dibutuhkan dari gua Petung ke mata air Sriti adalah sekitar 2 jam dan ke mata air Beton adalah sekitar 10 jam. Temuan ini sangat bersesuaian dengan hasil analisis kimia air dan isotop stabil dari lokasi penelitian.

As an interconnected power system via a High-Voltage Direct Current (HVDC) link is subjected to a rapid load change with the frequency of inter-area oscillation mode, system frequency and tie line power may be severely disturbed and oscillate. To compensate for the rapid load change and stabilize both frequency and tie line power oscillations due to the inter-area mode, the dynamic power flow control via a HVDC link can be exploited. To implement this concept, a new design method of HVDC-based controller is proposed. To grasp a physical characteristic of the inter-area oscillation frequency, the technique of overlapping decompositions is employed to achieve the subsystem embedded with the inter-area mode. Consequently, the second-order lead/lag controller of HVDC link can be designed in this subsystem. To acquire the desired overshoot of frequency oscillations, the parameters of the controller are automatically optimized by the Tabu Search (TS) algorithm. The effectiveness of the designed controller is investigated in a three-area longitudinal interconnected power system which represents the interconnection between the south of Thailand and Malaysia power systems.

Today, reflow soldering is a commonly used technique to establish large-area joints in power electronics modules. These joints are needed to attach large-area (>1 cm2) power semiconductor chips to the substrate, e.g., a direct-bond copper substrate, and the multichip module substrate to a copper base plate for heat spreading. Thermal performance, specifically thermal conductivity and thermomechanical reliability, of these large-area joints are critical to the electrical performance and lifetime of the power modules. Soft solder alloys, including the lead-tin eutectic and lead-free alternatives, have low thermal conductivities and are highly susceptible to fatigue failure. As demands mount for higher power density, higher junction temperature, and longer lifetime out of the power modules, reliance on solder-based joining is becoming a barrier for further advancement in power electronics systems. Recently, we successfully demonstrated lowtemperature sintering of nanoscale silver paste as a lead-free solution for achieving highperformance, high-reliability, and high-temperature interconnection of small devices (<0.09 cm2). In this paper, we report the results of our study to extend the low-temperature sintering technique to large-area joints. The study involved redesigning the organic and inorganic components of the nanoscale silver paste, analyzing the burnout kinetics of the various organic species sandwiched between large-area plates, and developing desirable temperature-time profile to improve sintering and bonding strength of the joints.

In the push to faster speed, lower power consumption, and reduced crosstalk, the conventional dielectric material SiO is going to be replaced by the materials with low dielectric constants. Although the current design that uses Cu and SiO dielectric material has achieved good reliability in wire bonding and flip-chip packages, whether or not the Cu-low k design can have the same reliability in these packages is unknown. Also, with decreasing dimensions and increasing complexity, thermal strains due to the mismatch of coefficients of thermal expansion are localized in very tiny zones with high magnitudes. Therefore, it is essential to find an experimental way to ensure interconnect layers to achieve required reliability. SIEM (Speckle Interferometry with Electron Microscopy) is a micro-mechanics measurement technique that has a spatial resolution approaching a few nanometers. It is able to perform the full field displacement mapping over a region of only several microns in diameter. The purpose of this paper is to demonstrate the capability of SIEM, which can perform a direct and in-situ measurement of local deformation fields of interconnection layers of an electronic chip.

Voltage rise is the main obstacle to prevent the increase of distributed generators (DGs) in low-voltage (LV) distribution grids. In order to maintain the power quality and voltage levels within the tolerance limit, new measurement techniques and intelligent devices along with digital communications should be used for better utilization of the distribution grid. This paper presents a real-time sensor-based online voltage profile estimation technique and coordinated Volt/VAR control in smart grids with distributed generator interconnection. An algorithm is developed for voltage profile estimation using real-time sensor remote terminal unit (RTU) which takes into account topological characteristics, such as radial structure and high R/X ratio, of the smart distribution grid with DG systems. A coordinated operation of multiple generators with on-load tap changing (OLTC) transformer for Volt/VAR control in smart grids has been presented. Direct voltage sensitivity analysis is used to select a single DG system for reactive power support in multi-DG environment. The on-load tap changing transformer is employed for voltage regulation when generators’ reactive power contributions are not enough to regulate the voltages. Simulation results show that the reported method is capable of maintaining voltage levels within the tolerance limit by coordinated operation of DG systems and on-load tap changing transformer.

In order to overcome thermal resistance issues in polymeric matrix composites, self-standing graphene aerogels were synthetized and infiltrated with an epoxy resin, in order to create conductive preferential pathways through which heat can be easily transported. These continuous highly thermally conductive 3D-structures show, due to the high interconnection degree of graphene flakes, enhanced transport properties. Two kinds of aerogels were investigated, obtained by hydrothermal synthesis (HS) and ice-templated direct freeze synthesis (DFS). Following HS method an isotropic structure is obtained, and following DFS method instead an anisotropic arrangement of graphene flakes results. The density of the structure can be tuned leading to a different amount of graphene inside the final composite. The residual oxygen, known to be detrimental to thermal properties, was removed by thermal treatment before the infiltration process. With 1,25 wt.% of graphene, using HS method, the thermal conductivity of the polymeric resin was increased by 80%, suggesting that this technique is a valid route to improve the thermal performance of graphene-based composites. When preferential orientation of the filler was present (DFS case), thermal conductivity was increased more than 25% with a graphene content of only 0,27 wt.%, demonstrating that oriented structures can further improve the thermal transport efficiency.

The issue of psychological feasibility of distance learning is understudied and remains relevant both in theoretical and practical terms. The purpose of the study viewed in the article is to identify the connection between students’ preferences to study using the Internet and electronic textbooks with their personal psychological traits. Presumably, confident, self-organized students have a positive attitude towards their use, while anxious, emotionally unstable students have a negative attitude. The study involves 1st – 4th year students (N = 270, aged from 17 to 21 years; 61.3% women) students, who specialize in Economics and Agricultural Industry in Izhevsk State Agricultural Academy. We used the following techniques: questionnaire developed by O. N. Malakhova, O. A. Zhuchenko, aimed at studying students’ preferences and Cattell’s Personality Factor Questionnaire (16-PF), form C, which has the goal to study personality traits that are significant for the research. It was found that there was a direct interconnection between students’ preference to use digital educational resources with their personal psychological traits. The study revealed that students with self-discipline and analytical mindset have a negative attitude to the use of electronic textbooks and distance learning. It was found that among the main personal psychological characteristics of students, which influence their preferences, are sensitivity and radicalism, anxiety and lack of self-discipline. We did not confirm the hypothesis put forward in the study. The applied aspect of the problem under study can be implemented in educational practice to increase the efficiency of educational process and in the development of digital training courses. The research perspectives are related to the study of teacher preferences.

Smart and sustainable cities require a network that can ensure many exchanges of information. In this sense, the deployment of optical fiber seems essential in order to guarantee urban interconnection. In this work, a new algorithm for the right shift code to be used in optical fiber communication (OFC) is proposed. The algorithm was designed to support different quality of services (audio, video, and data) for smart cities. This algorithm was based on varying the code weight for a certain number of users and transmitting a service to them. This algorithm was used for a spectral amplitude-coding optical code division multiple-access (SAC-OCDMA) system. Two detection scheme approaches were used, which are the single photodiode (SPD) detection technique and the direct detection (DD) technique. The performance was analytically studied for the proposed system in terms of BER, SNR, and the maximum number of users. The obtained results, when our system used SPD, showed an improvement in the number of users, about 2.5% at 622 Mbps and 1.4% at 1.25 Gbps and 2.5 Gbps. It can support a number of users up to 151 for video services at BER = 10−12, 300 for audio services with BER = 10−3, and 162 for data services at BER = 10−9 at a data rate of 1.25 Gbps. Furthermore, the system was simulated and showed transmission distances of 30 km at 1.25 Gbps and 6 km at 2.5 Gbps for video services, 80 km at 1.25 Gbps and 30 km at 2.5 Gbps for audio services, and 44 km at 1.25 Gbps and 13 km at 2.5 Gbps for data services. Our proposed system is suggested to be implemented in a fixed fifth-generation passive optical network (F5G PON).

Vector control of an asynchronous machine is traditionally accomplished by analogizing it to a separately excited DC machine. It provides decoupled torque and flux control that is perpendicular to each other, ensuring that neither vector interferes with the other. So, despite their close interconnection, torque and speed control are accomplished separately. The rotor flux is aligned with the direct axis of the synchronously rotating reference frame to achieve this. The PI controllers are critical in achieving the variable frequency drive (VFD) desired topology. The system employs three types of controllers: flux, speed, and torque. The flux controller is easy to tune, but the speed and torque controllers are more difficult to tune because the speed controller's output is the torque controller’s reference signal. Furthermore, there is no well-defined method for tuning the controllers in a vector control system. However, perfect tuning is required for the machine’s better dynamic behavior. It is clear from the above analysis that system identification is critical for tuning PI controllers. However, as an asynchronous machine, obtaining a decoupled system transfer function is extremely difficult. To solve this problem, the proposed system combines a seven-level pulse width modulation (PWM) inverter for vector control of a three-phase asynchronous nonstandard induction machine used in critical applications in nuclear power plants with a sliding mode control technique that eliminates the complexity of PI tuning. A second-order sliding mode controller could be used in the future to reduce the chattering and parameter variation effects. This controller can be enhanced with fuzzy logic principles to make it more robust and reliable, allowing it to be used in future drive designs for high-rating motors with critical applications.

Item-based collaborative filtering is one of the most popular techniques in the recommender system to retrieve useful items for the users by finding the correlation among the items. Traditional item-based collaborative filtering works well when there exists sufficient rating data but cannot calculate similarity for new items, known as a cold-start problem. Usually, for the lack of rating data, the identification of the similarity among the cold-start items is difficult. As a result, existing techniques fail to predict accurate recommendations for cold-start items which also affects the recommender system’s performance. In this paper, two item-based similarity measures have been designed to overcome this problem by incorporating items’ genre data. An item might be uniform to other items as they might belong to more than one common genre. Thus, one of the similarity measures is defined by determining the degree of direct asymmetric correlation between items by considering their association of common genres. However, the similarity is determined between a couple of items where one of the items could be cold-start and another could be any highly rated item. Thus, the proposed similarity measure is accounted for as asymmetric by taking consideration of the item’s rating data. Another similarity measure is defined as the relative interconnection between items based on transitive inference. In addition, an enhanced prediction algorithm has been proposed so that it can calculate a better prediction for the recommendation. The proposed approach has experimented with two popular datasets that is Movielens and MovieTweets. In addition, it is found that the proposed technique performs better in comparison with the traditional techniques in a collaborative filtering recommender system. The proposed approach improved prediction accuracy for Movielens and MovieTweets approximately in terms of 3.42% & 8.58% mean absolute error, 7.25% & 3.29% precision, 7.20% & 7.55% recall, 8.76% & 5.15% f-measure and 49.3% and 16.49% mean reciprocal rank, respectively.

The 3-D interconnection started at 3D PLUS in 1996 and led to the stacking of nearly all types of analogical and logical components, sensors, MEMS, etc for the Hi-Rel field (Space, Defence, Medical, Industrial). This technology is extremely robust (−130°C +175°C, 40000g), and is fully qualified by all worldwide most important Space Agencies and for Defence applications. A technological break started in 2002 ; It consisted in another 20 to 30 reduction factor of the weight and volume of these 3-D modules.The Z pitch is 100μm and the X Y size is given by the size of the larger die plus 100μm of polymer around it. This is a stacked of Known Good Rebuilt Wafer of full wafer level technique. The dice are received in wafers and following operations are carried out :- Pick, flip and place of the good dice on a “sticking skin”- Moulding of the whole of this « pseudo wafer » in order to obtain what we call a « Known Good Rebuilt Wafer (KGRW) ». These two first steps are already developed by Infineon and mainly Freescale (RCP technique up to 300mm)- Stacking and gluing of KGRW 1, 2, 3…, n, by means of an adhesive film- Dicing of these stacked rebuilt wafers by techniques identical to the dicing of standard wafers- Metallization of the dicing streets with nickel + gold by electroless chemical plating identical to the UBM plating technique- Direct laser patterning by laser with our edge connection technique up to 100μm pitch. Below this pitch, the Thru Polymer Via (TPV) are made through the stacked wafers. The equivalent pitch will be 20μm. it can be noticed that the shielding can be made on the dicing street.- Electrical test at the stacked wafer level- Singulation of the 3D modules This approach allows using standard dice without any modification. It is multi sources and the stacking of the good rebuilt wafers allows to get an excellent yield. A development agreement has been signed with a semiconductors manufacturer. A development is in progress with the most worldwide important manufacturer of smart cards in order to integrate 5 levels of dice (including a MEMS) within a cavity of 550 μm inside the 800μm SIM card. Other applications with MEMS will be presented:- “Abandoned Sensors” for Heath Monitoring of the aircraft structure developed during the European Program: “e-Cubes” ,- Gyroscope with 6 MEMS,- Micro camera for endoscopy…- Medical applications with an important development made for 3 major pacemaker manufacturers. This « full wafer level » approach will allow to build System in Package (SiP) or “Abandoned Sensors” at very low costs, since the process uses mainly the steps of wafers building; the “panelization” allows to be in parallel processing from A to Z steps. Moreover, the use of Known Good Rebuilt Wafer like the RCP allows stacking Good wafer at the reverse what is impossible with the wafer to wafer approach.

In applications such as image sensors or solar cells, the performance of the device can be improved thanks to the passivation of the silicon substrate using high-k dielectrics such as alumina, hafnium dioxide etc. To assess the quality of the dielectric/semiconductor interface, conventional electrical characterization techniques can be employed, but they require fabrication of dedicated test devices. Among the methods that can be directly used at wafer-level, COCOS [1] allows obtaining electrical information such as the interface states density, but the charging of the sample surface can be an issue. In this paper, we discuss an alternative sensitive and non-destructive optical technique to characterize the electrical properties of a passivation scheme: the second harmonic generation (SHG). In centrosymmetric materials, in the dipolar approximation, the bulk SHG response is zero [2], so the signal mainly contains interface-related information. In particular, when a static electric field (Edc) is present at the interface, the SHG is reinforced and a phenomenon called EFISH (electric field SHG) appears [3]. The electric field at the interface between a dielectric and a semiconductor is related to fixed charges (Qox) and/or interface states (Dit), so the SHG signal can provide these two parameters. Additionally the technique has a potential to probe small areas (within the micrometer size). In this work, the study is focused on the ability of the SHG to measure Qox. The samples used have a layer of Al2O3 of 13nm thickness on Si (100), deposited with different processes, followed or not by an annealing. The annealing step is known to activate negative charges in alumina layers, which promotes the field effect passivation and it can also modify the interface defects [4]. The samples were measured with the SHG tool from FemtoMetrix [5]. Complementary electrical characterizations were performed with the COCOS technique on the full wafer and with capacitance versus voltage (C-V) on dedicated MOS capacitors, in order to obtain Qox. The electric field at the interface can then be calculated through Gauss’ law. Figure 1a shows a typical experimental response of the SHG versus time, obtained on two different samples. The parameters Qtot and Dit were extracted through COCOS. The time-dependence of the SHG is due to the time-dependence of the electric field during the measurement because of charging/discharging effects by carriers generated under the incident laser of the SHG. The SHG signature is obviously stronger for a high Qtot, which indeed is associated with a higher electric field at the interface. Figure 1b shows (with symbols) the experimental results of SHG versus the incidence angle (AOI) for the two samples. The increase of SHG signal for the sample with higher Qtot is confirmed, regardless of the angle of incidence. A general calibration, only based on these types of measurements is not sufficient, since optical phenomena such as transmission & interferences depend on the thickness of the layers involved. In order to better anticipate the effect of these phenomena for a future calibration, we developed a home-made simulator, based on absorption in each layer, boundary conditions at each interface and which contains the “static” interface electric field between materials. Using the electric field calculated with the charge parameters extracted from the COCOS/C-V measurements, we traced the simulated SHG versus AOI (Figure 1b, lines). The tendency observed in experiments is reproduced, even though the simulations are not fully superimposed. This mismatch is probably due to the fact that some of the material parameters in the simulations (e.g. the non-linear susceptibility values) are not very well known. The full paper will show additional samples, corresponding C-V and SHG experimental and simulated data, with the aim of proposing a calibration method that would allow the direct extraction of Qox based only on the SHG measurement. Acknowledgements This work was supported by the French National Plan Nano2022, within the IPCEI Nanoelectronics for Europe program. [1] M. Wilson, J. Lagowski, L. Jastrzebski, A. Savtchouk, and V. Faifer, AIP Conference Proceedings, 2001, vol. 550, no. 1, pp. 220–225. [2] R. W. Boyd, Nonlinear optics. Academic press, 2020. [3] N. M. Terlinden, G. Dingemans, V. Vandalon, R. Bosch, and W. M. M. Kessels, J. Appl. Phys., vol. 115, no. 3, p. 033708, 2014. [4] D. K. Schroder. John Wiley & Sons, 2015. [5] http://femtometrix.com Figure 1

The 3-D interconnection started at 3D PLUS in 1996 and led to the stacking of nearly all types of analogical and logical components, sensors, MEMS, etc for the Hi-Rel field (Space, Defence, Medical, Industrial). This technology is extremely robust (−130 °C +175 °C, 40000g), and is fully qualified by all worldwide most important Space Agencies, for Defence applications and Harsh environment. A technological break started in 2002 ; it consisted in another 20 to 30 reduction factor of the weight and volume of these 3-D modules. The Z pitch is 100 μm and the X Y size is given by the size of the larger die plus 100 μm of polymer around it. This is a stacked of Known Good Rebuilt Wafer of full wafer level technique. The dice are received in wafers and following operations are carried out :- Pick, flip and place of the good dice on a “sticking skin”- Moulding of the whole of this « pseudo wafer » in order to obtain what we call a « Known Good Rebuilt Wafer (KGRW) ». These two first steps are already developed by Freescale (RCP technique up to 300mm), then Infineon and Nanium (ex Infineon/Quimoda) and now about ten companies are developing this 2-D approach:- Stacking and gluing of KGRW 1, 2, 3..., n, by means of an adhesive film- Dicing of these stacked rebuilt wafers by techniques identical to the dicing of standard wafers- Metallization of the dicing streets with nickel + gold by electroless chemical plating identical to the UBM plating technique- Direct laser patterning by laser with our edge connection technique up to 100 μm pitch. Below this pitch, the Thru Polymer Via (TPV) are made through the stacked wafers. The equivalent pitch will be 20 μm. it can be noticed that the shielding can be made on the dicing street.- Electrical test at the stacked wafer level- Singulation This approach allows to use standard dice without any modification. It is multi sources and the stacking of the good rebuilt wafers allows to obtain an excellent yield. A development agreement has been signed with a semiconductors manufacturer. Smart card application- A development is in progress with the most worldwide important manufacturer of smart cards in order to integrate 5 levels of dice within a cavity of 550 μm inside the 800 μm SIM card. Medical applications will be presented:- Micro modulator with 5 ASICs within a 3 mm diameter tube,- Prototypes for the major US pacemaker manufacturer (Medtronic) and one European pacemaker manufacturer (Sorin/Ela Medical). A full pacemaker module of 0,5 cm3 (16 times smaller than the standard pacemaker: 8 cm3) will be shown- Micro camera for Hard X-Ray for Philips Medical (DE). Industrial applications- Abandoned sensors for Airbus and industrial areas. This « full wafer level » approach will allow to build System in Package (SiP) or “Abandoned Sensors” at very low costs, since the process uses mainly the steps of wafers building; the “panelization” allows to be in parallel processing from A to Z steps. Moreover, the use of Known Good Rebuilt Wafer like the RCP allows to stack Good wafer at the reverse what is impossible with the wafer to wafer approach.

Abstract Patients with severe factor VIII (FVIII) deficiency (hemophilia A [HemA]) develop neutralizing antibodies (inhibitors) against FVIII in up to ~30% of cases. For HemA patients with inhibitors, activated recombinant factor VII (rFVIIa) is a treatment option. High levels of rFVIIa are required for treating HemA patients with inhibitors to induce direct activation of factor X on the surface of activated platelets via a tissue factor (TF)-independent mechanism (Hoffman M, Monroe DM. Thromb Res. 2010;125(suppl 1):S16-S18). To assess how rFVIIa-mediated clot formation in HemA patients with inhibitors may differ from unaffected individuals, we compared the effect of rFVIIa on HemA versus control (or HemA supplemented with 100% FVIII) clot formation in human and/or mouse systems. By TF-induced thrombin generation assay, increasing rFVIIa from 5 nM to 100 nM did not appreciably alter the kinetics or extent of thrombin generation compared with the same human HemA plasma containing 100% FVIII. Confocal microscopy of human HemA plasma clots generated with 75 nM rFVIIa and TF showed few branching fibrin fibers and an open fibrin meshwork. In contrast, TF-induced coagulation of the same HemA plasma containing 100% FVIII formed fibrin clots with numerous branches, interconnecting to form a dense meshwork. To confirm that these findings reflect rFVIIa-mediated clot formation in vivo, we assessed the intrinsic coagulation of mouse HemA whole blood collected without anticoagulant and spiked with rFVIIa. Intrinsic coagulation with rFVIIa was assessed by T2 magnetic resonance (T2MR), a technique capable of monitoring the separation of whole blood into serum, loose-clot, and tight-clot compartments during coagulation (Skewis et al. Clin Chem. 2014;60:1174-1182; Cines et al. Blood. 2014;123:1596-1603). By T2MR, rFVIIa induced the separation of HemA whole blood into the serum and clot compartments, indicating that the reduced fibrin generation with rFVIIa did not interfere with whole blood coagulation. Furthermore, saphenous vein puncture of HemA mice treated with rFVIIa showed a dose-dependent decrease in clot times. Scanning electron microscopy of the clots extracted from these HemA mice indicated markedly different composition than clots extracted from wild-type mice. In wild-type clots, fibrin and polyhedral erythrocytes formed a large proportion of the total structures. In contrast, clots from rFVIIa-treated HemA mice consisted primarily of platelets and erythrocytes with forms intermediate between discoid and polyhedral but, surprisingly, low fibrin content. Taken together, these data suggest that rFVIIa-mediated clot formation may require greater activated platelet involvement, which would be consistent with the TF-independent mechanism of action proposed for rFVIIa in HemA. Finally, the compositional difference between clots from wild-type versus HemA mice dosed with rFVIIa suggest that evaluating HemA therapies for their ability to form more physiologic clots could be an approach to improve treatment options for patients with HemA. Disclosures Leong: Bayer: Employment. Xu:Bayer: Employment. Mallari:Bayer: Employment. Wong:Bayer: Employment. Sim:Bayer: Employment. Cuker:Stago: Consultancy; Genzyme: Consultancy; Amgen: Consultancy; Biogen-Idec: Consultancy, Research Funding; T2 Biosystems: Research Funding. Marturano:T2 Biosystems: Employment. Lowery:T2 Biosystems: Employment. Kauser:Bayer: Employment. Weisel:Bayer: Research Funding.

ABSTRACTUsing a leakage-compensated charge (LCCV) technique to obtain static capacitance-voltage (C-V) curves, we extend the standard high-low C-V method for determining the interface state level density, Dit as a function of energy in the silicon band gap to metal-oxide-silicon capacitors in the direct tunneling regime (oxide thickness ∼<3.5 nm). The LCCV technique yields true static C-V curves for oxides at least as thin as 2.8 nm, where the tunnel leakage current is so high that the usual quasistatic C-V measurement is not possible. As applications of this method, Dit is compared for fresh oxides of different tunnel thickness, and Dit is measured before and after constant voltage stress of a 3.5-nm oxide. The stress results indicate, as in other work on thicker oxides, that interface traps are created during the stress, with peak densities both below and above midgap. This approach is expected to be useful for evaluating both ultra-thin oxides and leaky alternate gate dielectrics.

ABSTRACTThis paper reviews several laser-based area-selective processing techniques developed for high-density multichip interconnection applications. Key material and process requirements for the development of a viable laser-direct-write interconnect technique on polyimide are addressed.

AbstractThe interest in laser processing technology has increased significantly in recent years because of increasing demands for application-specific IC design and fabrication, yield enhancement, circuit restructuring, and prototyping; all of these benefit from an adaptive processing technique using direct energy for improvement of precision, resolution, process automation, and turnaround time. This paper reviews several laser-patterned metallization techniques developed for high-density multichip interconnection applications. Key material and process requirements for developing a viable laser-direct-write interconnect technique on polyimide are addressed.

Purpose The purpose of this paper is to develop a generalized observer and controller for brushless direct current (BLDC) motor to make the system more robust for parameter variations, load torque and speed tracking. Design/methodology/approach A robust interconnection and damping assignment passivity-based control (IDA-PBC) technique for BLDC motor is introduced in this paper. The IDA-PBC is used to obtain the reference voltages for pulse width modulation (PWM) control. The immersion and invariance (I&I) observer is used to estimate the load torque and speed of the BLDC motor. At the time of starting, the motor rotates in arbitrary direction, and sometimes, because of the cogging action, it may take a huge current. Therefore, a new start-up method is proposed for the BLDC motor, which maintains the alignment of the rotor. Findings From the simulation and experimental results, it can be seen that the proposed controller and observer satisfactorily work for parameter variations, load torque and speed tracking. Originality/value The authenticity of the proposed technique is tested experimentally on two different BLDC motors using low-cost 32-bit STM32F407VG microcontroller. The response of the proposed technique is evaluated by changing motor parameters such as stator resistance, inductance, flux linkage constant and torque constant.

ABSTRACTWe find that the density of electronically active defect states, formed close to the Si/SiO2 interface during high temperature oxidation (Tox > 800°C), is proportional to the thickness-averaged stress or strain in the oxide layer. This was established by measuring the midgap interface state density, Dit, and correlating it with: i) a direct measurement of the stress, using a beam deflection technique; and ii) a determination of the oxide strain, using infrared (IR) spectroscopy and a model that relates the frequency of the Si-O bond-stretching vibration to the microscopic strain in the oxide.In addition, the elastic stress at the Si/SiO2 interface has been modified by film deposition onto the SiO2 surface of Si:3N4 film or a variable thickness of an Al gate metal. The additional elastic stress introduced by these depositions did not influence Dit. These observations lead us to conclude that interface traps are generated by “local plastic deformations” that occur during the oxidation process, and are localized in the immediate vicinity of the Si/SiO2 interface.

This paper deals with (i) damping improvement and (ii) energy management of a DC microgrid for improvement of its stability. The direct current (DC) microgrid has a solar-photovoltaic system as a renewable source and fuel cell-battery combination as a backup system to supply power to constant power loads (CPLs). The presence of CPLs in a DC microgrid makes the stability problem more challenging since the negative impedance characteristics of CPLs bring instability into the system. A control approach using interconnection and damping assignment-passivity based control (IDA-PBC) is proposed in this paper to address both the objectives. The proposed control approach provides an efficient energy management, the required damping and also maintains the stability by making the system passive. The tuning parameters of the control laws are adapted incorporating the state of charge (SoC) for the effective energy management. In addition, an integral action is added with the proposed control laws to eliminate the steady-state error in the voltage level of the DC bus and load bus. The proposed IDA-PBC control along with an integral action is compared with four other control approaches, and reveals its better performances. The MATLAB/Simulink results show that the proposed control technique provides better responses in terms of providing damping and effective energy management.

ABSTRACTLaser direct-write processes are attractive complements to traditional methods of fabricating microelectronic circuitry. This paper is a summary of our work in applying such processes to high-density inter-chip interconnection modules, such as those using copper conductors on polyimide dielectric layers. We begin by discussing the requirements which laser processes must satisfy in order to be useful in this application. An analytical model of laser heating is then described, which aids in understanding the thermal problem of absorption of visible-wavelength laser light by polyimide. Calculations using this model are consistent with experimental observations. Finally, we focus on one laser processing technique: laser chemical vapor deposition. We describe a new process for laser chemical vapor deposition of tungsten on polyimide, which enables the formation of low resistance contacts (≈ 0.1 Ω) between the deposited tungsten films and pre-patterned nickel-coated copper conductors. Lines approximately 30 /m wide and 34 µm thick were deposited at a scan rate of 93 µm/s. From four-point resistance measurements of different lengths of deposited films, the tungsten film resistivity is estimated to be two to three times the bulk value.

In a postulated severe accident, a molten pool with decay heat can form in the lower head of a reactor pressure vessel, threatening the vessel’s structural integrity. Natural convection in molten pools with extremely high Rayleigh (Ra) number is not yet fully understood as accurate simulation of the intense turbulence remains an outstanding challenge. Various models have been implemented in many studies, such as RANS (Reynolds-averaged Navier–Stokes), LES (large-eddy simulation), and DNS (direct numerical simulation). DNS can provide the most accurate results but at the expense of large computational resources. As the significant development of the HPC (high-performance computing) technology emerges, DNS becomes a more feasible method in molten pool simulations. Nek5000 is an open-source code for the simulation of incompressible flows, which is based on a high-order SEM (spectral element method) discretization strategy. Nek5000 has been performed on many supercomputing clusters, and the parallel performance of benchmarks can be useful for the estimation of computation budgets. In this work, we conducted scalability tests of Nek5000 on four different HPC clusters, namely, JUWELS (Atos Bullsquana X1000), Hawk (HPE Apollo 9000), ARCHER2 (HPE Cray EX), and Beskow (Cray XC40). The reference case is a DNS of molten pool convection in a hemispherical configuration with Ra = 1011, where the computational domain consisted of 391 million grid points. The objectives are (i) to determine if there is strong scalability of Nek5000 for the specific problem on the currently available systems and (ii) to explore the feasibility of obtaining DNS data for much higher Ra. We found super-linear speed-up up to 65536 MPI-rank on Hawk and ARCHER2 systems and around 8000 MPI-rank on JUWELS and Beskow systems. We achieved the best performance with the Hawk system with reasonably good results up to 131072 MPI-rank, which is attributed to the hypercube technique on its interconnection. Given the current HPC technology, it is feasible to obtain DNS data for Ra = 1012, but for cases higher than this, significant improvement in hardware and software HPC technology is necessary.

Today’s consumer market demands electronics that are smaller, faster, and cheaper. To cater to these demands, novel materials, new designs, and new packaging technologies are introduced frequently. Wafer level chip scale package (WLCSP) is one of the emerging package technologies that have the key advantages of reduced cost and smaller footprint. The portable consumer electronics are frequently dropped; hence, the emphasis of reliability is shifting toward the study of effects of mechanical shock loading increasingly. Mechanical loading typically induces brittle fractures (also known as intermetallic failures) between the solder bumps and the bond pads at the silicon die side. This type of failure mechanism is typically characterized by the board level drop test. WLCSP is a variant of the flip-chip interconnection technique. In WLCSPs, the active side of the die is inverted and connected to the printed circuit board (PCB) by solder balls. The size of these solder balls is typically large enough (300 μm pre-reflow for 0.5-mm pitch and 250 μm pre-reflow for 0.4-mm pitch) to avoid the use of underfill that is required for the flip-chip interconnects. Several variations are incorporated in the package design parameters to meet the performance, reliability, and footprint requirements of the package assembly. The design parameters investigated in this effort are solder ball compositions with different silver (Ag) contents, backside lamination with different thicknesses, WLCSP type—direct and redistribution layer (RDL), bond pad thickness, and sputtered versus electroplated under bump metallurgy (UBM) deposition methods for 8 × 8, 9 × 9, and 10 × 10 array sizes. The test vehicles built using these design parameters were drop tested using Joint Electron Devices Engineering Council (JEDEC) recommended test boards and conditions as per JESD22-B11. Cross-sectional analysis was used to identify, confirm, and segregate the intermetallic and bulk solder failures. The objective of this research was to quantify the effects and interactions of WLCSP design parameters through drop test. The drop test data were collected and treated as a right censored data. Further, it was analyzed by fitting empirical distributions using the grouped and ungrouped data approach. Data analysis showed that design parameters had a significant effect on the drop performance and played a vital role in influencing the package reliability.

Background:: The heart is the central organ of the circulatory system which maintains the flow of blood along with the transport of nutrients to different cells and tissues. A well-functioning cardiac state is a complicated mode of changeability. A healthy heart is not only about oscillation as the rhythmometer is not the same in every circumstance. Heart rate shows variations so that it can be regulated according to psychophysiological conditions to maintain the effect of the internal-external stimulus. Objective:: The main objective of this review is to provide a piece of all-inclusive information about heart rate variability (HRV) and different variables affecting HRV. The direct interconnection among factors and so that HRV can be used in clinical practices. Methods:: This review article contains a detailed survey of literature about HRV available in different online sources such as; Google Scholar, Science Direct, PubMed, and Web of Science, etc. In this review, the authors have focused on the role of the autonomic nervous system in the regulation of HRV and the role of various factors affecting HRV. Results:: The variation in the time between two heartbeats is termed as HRV. It is one of the indicators of many pathological conditions related to cardiovascular health. It provided reliable information about the interaction of the sympathetic and parasympathetic nervous systems. The analysis of the variation of heart rate is a well-known non-invasive technique to identify the functioning of the autonomic nervous system. The autonomic nervous system (ANS) depends on the sympathetic and parasympathetic nervous system for transferring information. The cardio-accelerating center, lungs, and non-striated muscles are innervated by cardiac sympathetic nerves. This division of ANS latches upon the heart accordingly via the cervicothoracic ganglion and vagus nerve. It is found that cardiac normal variability depends upon this stimulation towards the sinoatrial node (pacemaker) which can be evaluated by analyzing the HRV. In human- based studies, it has been found that low level of HRV is one of the main causes of death rate among adults. Hence, HRV helps in identifying the risk of cardiac diseases and the state of ANS. Conclusion:: The heart plays a vital role in the human body and the well-functioning of the cardiac system is the need for a healthy life. The heart contains its nervous system termed as neurocardio system in which ANS plays a key role in which the sympathetic and parasympathetic system interplay to regulate HRV. High HRV is associated with healthy condition while low HRV is associated with pathological conditions. The HRV is influenced by various variables such as; pathological, physiological, psychological, environmental factors, lifestyle factors, and genetic factors, etc.

Em 1945, prefaciando uma obra de Lins e Silva, Gilberto Freyre lembrava o projeto de controle psiquiátrico dos terreiros, coisa que o “espírito humanitário” de Nina Rodrigues concebeu como alternativa à brutalidade das intervenções policiais, da repressão direta a esses centros de culto de religiões afrobrasileiras. Nina não o conseguiu implantar, mas – lembra ainda Gilberto Freyre –, este projeto de monitoramento das religiões negras por psiquiatras e etnólogos mais tarde veio a ser realizado com um êxito que o ilustre prefaciador acentua: Ulysses Pernambucano o pôs em prática em Recife; em Salvador, diz Freyre ainda, executaramno “técnicos capazes”, arregimentados pelo major Juracy Magalhães – que então governava a Bahia como interventor. Segundo o autor de Casa Grande e Senzala, essa iniciativa de Ulysses Pernambucano e dos peritos baianos veio a ser “uma das intervenções mais felizes da ciência e da técnica antropológica, orientada por uma psiquiatria social, na vida de uma comunidade brasileira”. PALAVRAS-CHAVE: candomblé, Museu Estácio de Lima, etnopsiquiatria, racismo, coleções afro-brasileiras.ON PSYCHIATRY, CANDOMBLE AND MUSEUMS Ordep Serra In 1945, on the foreword of a work by Lins e Silva, Gilberto Freyre recalled the project of lembrava o projeto psychiatric control of candomble temples, “terreiros”, something conceived by Nina Rodrigues’s “humanitarian spirit” as an alternative to the brutality of police interventions, direct repressions to these cult centers of African-Brazilian religions. Nina could not make it work, but – as Gilberto Freyre recalls – this project of monitoring black religions by psychiatrists and ethnologists came into being later with a success the illustrious foreword author points out: Ulysses Pernambucano put it in practice in Recife; in Salvador, says yet Freire, it was executed by “capable technicians” recruited by major Juracy Magalhães – that governed Bahia at the time as an interventor. According to the author of Casa Grande e Senzala, this initiative of Ulysses Pernambucano and Bahian experts became “one of the happiest interventions of anthropological science and technique, oriented by a social psychiatrist, in the life of a Brazilian comunity”. KEYWORDS: candomblé, Estácio de Lima Museum, ethnopsychiatry, racism, African-Brazilian collections.A PROPOS DE LA PSYCHIATRIE, DU CANDOMBLÉ ET DES MUSÉES Ordep Serra En 1945, dans la préface d’une oeuvre de Lins et Silva, Gilberto Freyre nous rappelait que le projet de contrôle psychiatrique des terreiros (lieux de culte du candomblé), avait été conçu selon “l’esprit humanitaire” de Nina Rodrigues comme une alternative à la brutalité des interventions de police et de la répression directe envers ces centres de culte des religions afro-brésiliennes. Nina Rodrigues n’a pas réussi à l’implanter, mais – nous rappelle encore Gilberto Freyre –, ce projet d’accompagnement des religions noires par des psychiatres et des ethnologues a été réalisé plus tard avec un succès que notre illustre auteur de la préface accentue: Ulysses Pernambucano l’a mis en oeuvre à Recife; à Salvador, nous dit encore Freyre, ceux qui l’ont exécuté étaient des “techniciens capables” enrégimentés par le major Juracy Magalhães qui à l’époque gouvernait Bahia en qualité d’intervenant. Selon l’auteur de Casa Grande e Senzala, cette initiative d’ Ulysses Pernambucano et des experts bahianais est devenue “l’une des interventions les plus heureuses de la science et de la technique anthropologique, accompagnée par une psychiatrie sociale, dans la vie d’une communauté brésilienne”. MOTS-CLÉS: Candomblé, Musée Estácio de Lima, ethnopsychiatrie, racisme, collections afro-brésiliennes.Publicação Online do Caderno CRH no Scielo: http://www.scielo.br/ccrh Publicação Online do Caderno CRH: http://www.cadernocrh.ufba.br

In this paper, I focus on disclosures by one participant as enabled by a kind of artistic practice that I term “participation cartography.” By using “participation cartography” as a framework for the analysis of Running Stitch (2006), a piece by Jen Southern (U.K.) and Jen Hamilton (Canada), I demonstrate that disclosures by participants in this practice are to be seen as a form of self-mapping that positions the self in relation to a given performance space. These self-positionings present the self in spatio-temporal terms and by means of performative narratives that re-define the subject from an isolated individual into a participant within an unfolding live process.It is my argument here that most of the participation performances to which the term “participation cartography” may be applied don’t have a mechanism for participants to share reflections about their participation experience embedded in the framework the artists provide. By discussing Running Stitch from some participant’s perspectives—mine included—I demonstrate that if such a sharing mechanism was provided, the participant’s disclosures would enact a poetics of sharing that at once reveals and conceals aspects of the self. “Participation cartography” performances hold the power to generate autobiographical conversations and exchanges. Without these (collective) conversations and exchanges, the disclosures made by participants in and through “participation performances” such as Running Stitch conceal more than what they reveal, shattering thereby the cartographic (self-mapping) power of these practices.Running Stitch (2006)This piece is a performative installation that involves the use of Global Positioning Technology and walking performances by participants in order to produce collaboratively a new kind of “map” or visual-art object, more concretely a tapestry. I experienced it in 2006 in Brighton (UK). It was commissioned by Fabrica, “a gallery promoting the understanding of contemporary art” (see: http://www.fabrica.org.uk/).The following is the description made by the artists of the work on their Website (see: http://www.satellitebureau.net/p8.php):Running Stitch is a 5m x 5m tapestry map, created live during the exhibition by charting the journeys of participants through the city...Visitors to the exhibition took a GPS-enabled mobile phone to track their journeys through the city centre. These walks resulted in individual GPS ‘drawings’ of the visitor’s movements that were then projected live in the exhibition to disclose hidden aspects of the city. Each individual route was sewn, as it happened, into a hanging canvas to form an evolving tapestry that revealed a sense of place and interconnection (see also fig. 1). Figure 1. Image: Jen Southern and Jen Hamilton. Running Stitch and audience members. Fabrica Contemporary Art Gallery, 2006.As the vocabulary used by the artists shows, the work was conceived at that time (2006) as a kind of collaborative map-making process by which previously “hidden aspects of the city” can be disclosed. My interrogation of this practice starts by questioning the assumption that cartography, as illustrated by cases such as this, refers to a physical or geographical space—the city. Through the lens of “participation cartography” I mean to show that that what is being mapped in and through practices such as Running Stitch is not (physical) space but the being-who-moves in space. Rather than the city, it is the multiple subjects-who-move in Brighton’s town centre on a particular day in 2006 and within the frame of this event what is the theme and content of the resulting tapestry and of the disclosures it may contain. Accordingly, the resulting visualisation (the map) is to be seen as a documentation of past performances by concrete individuals rather than as a visual representation of urban space or as an autonomous visual-art object. Practices such as this are a particular form of “spatial auto-bio-graphical” performance art. In these practices, the boundaries between notions of cartography and autobiography are blurred and need to be critically addressed.More established critical vocabularies such as locative media (Hemment), psychogeography (Kanarinka), collaborative mapping (Sant), map-art (Wood), or counter-cartographies (Holmes), with which similar works have been discussed typically focus on studying the relationships between the resulting visual-art objects and notions of space, as well as on issues of representation. Similarly, the term site-specific performance, as articulated for instance by Nick Kaye, draws attention primarily to the physical location in which the meaning of a given artwork may be defined (1), rather than on the participation experience by the subject who engages with the artistic process. In my view, a participants-centred approach is needed in order to adequately understand the power of participation performances such as Running Stitch (2006) and its connections with ‘auto-bio-graphical’ performance. Participation Cartography: A New Vocabulary“Participation cartography” introduces an ontological shift in what is typically considered performance art. From live gestures, or more precisely, “live art by artists,” as art historian Rose Lee Goldberg (9) has defined it, performance is re-defined by these practices into live art by participants in response to a spatio-temporal interaction framework provided by artists.Running Stitch illustrates a kind of practice in which the artists’s creation is not a finished artwork or arrangement of actions and conditions (a conventional performance). Rather, the artists’s creation is a kind of “open work” in the sense that the active role of the participant is envisaged by the artist at the very moment of conceiving the work (Eco 3). The participant is, moreover, conceived of by the artist as an individual who collaborates with the artist or group of artists in the very production of the artwork. From an ontological point of view, I conceptualise more specifically practices such as Running Stitch as what Allan Kaprow termed “participation performances,” that is, performances in which those who take part are literally, the ingredients of the performances (Kaprow 184). These were lifelike pieces in which normal routines by non-actors became the performance of a routine. In participation performances or activities every day life “performances” or “presentations of self” (Goffman) are framed as art, and more concretely, as a happening or a new form of theatre or performance art. For instance, by means of instructions to be enacted by non professional performers, in Kaprow’s participation performance Maneuvers the daily routine of the courtesy shown another person when passing through a doorway becomes the artistic performance of that routine (191).I conceptualise practices such as Running Stitch as a particular form of “participation performance,” namely as “participation cartography.” The cartographic power of such practices needs to be studied from the participant’s perspective. Let me illustrate this idea by discussing Running Stitch more in detail.Over a four weeks period, more than hundred participants collaborated in the production of the object called by the artists “the tapestry map”. Each walk was represented by a line of stitches on the canvas, and each walk was stitched with a different colour. At the end of the process, the tapestry was a colourful and intertwined collection of threads stitched onto the same surface (see fig. 2). Figure 2. Image: Jen Southern and Jen Hamilton. Running Stitch and audience members. Fabrica Contemporary Art Gallery, 2006.But, what did each thread disclose about each participant? Who are they? What exactly is disclosed to whom?On DisclosureIn Running Stitch it is possible to speak of two moments of disclosure, each moment illustrating a different scope of the verb “to disclose.” First, there is the disclosure in real time of the physical location of each walker. Second, there is the disclosure of the sense of purpose of the journey and of all what happened to the participant during the walk and after when confronted with the visualisation of her personal walk. It is this second disclosure what can infuse the “map” with personal meaning.In the first case, disclosure is associated with surveillance. Positioning, as used within the framework of Global Positioning Systems, refers to the computational process whereby the geographical location of the carrier of the GPS device can be pinpointed, usually on a conventional digital map. “To disclose” means here to make visible and, more precisely, to “draw” by means of technology the whereabouts of someone—an anonymous other—who is outside of the gallery walking about Brighton’s city centre. This first moment of disclosure happens for all to be seen in the gallery. It is framed by the artists as the core of what constitutes Running Stitch as an artwork.However, the technology-aided map-making that takes place here conceals the mental processes and the autobiographical stories that go with the actual walk—where did the participants go and why, what made them be there in the first place? This can only be known if the participant is given a voice for him or her to “map” herself by presenting the Self in spatio-temporal terms within the public arena of the ongoing artistic event. This would require an additional sharing mechanism to be embedded within the framework provided by the artists. As organised by the artists, two participants at a time were walking during one hour outside in Brighton’s town centre in the area surrounding the Fabrica Gallery. While this was happening, other members of the public could witness the unfolding journeys live on the canvas inside the gallery. While one was watching, there were of course random and casual opportunities to engage in conversations with other onlookers. However, the artists did not devise more formal opportunities for the public to engage in conversations with previous participants or with other onlookers. After the two walkers in turn had returned to the gallery and finished their walks, the next set of walkers would depart. Typically, the previous walkers would stay for some minutes watching at the resulting visualisation of their walk—the running stitches—on the canvas. The framework provided by the artists placed these previous walkers as onlookers rather than as ‘official’ commentators of their own walks. Their comments and their thoughts on the running stitches representing their walk remained secret—concealed, unless spontaneous conversations would randomly communicate (reveal) them.Fortunately, the artists did ask participants-walkers to fill anonymously a feedback sheet before leaving the gallery. In that sheet, participants had an opportunity to share their comments and thoughts about their participation experience with the artists in writing. These responses provide the evidence that, in practices such as this, a second disclosure moment can take place and, indeed, needs to be seen as integral to the cartographic process. Disclosure, in this second moment, is not associated with surveillance but with the ideas of sharing, self-reflexion, subjective positioning, and self-mapping.“My walk was an act of love…”One Running Stitch participant wrote anonymously in the above mentioned feedback sheet:My walk was for a friend of mine –Sandra- who’s very ill. I wanted to go past various landmarks that had meaning for us both and end up in Prestor Park where I could make a large S shape. There was another park where we used to meet where I wanted to make an ‘X’ shape. Sandra signed her e-mails SX. (“My walk was an act of love”).This testimony, which was not shared with others during the cartographic process called Running Stitch but framed by the artists as private participants’s feedback, not only comments about the walk but constitutes it. This story explains what makes the participant ‘be there’, go to Prestor Park, and walk/draw an “X” shape on the canvas. Rather than a statement about place in itself, it is a “spatial auto-bio-graphical” presentation of Self as a friend of Sandra. Within the framework of “participation cartography,” a “spatial auto-bio-graphical presentation” is a presentation of Self in spatio-temporal terms that involves an act of self-reading. By means of reflexive language, the participant gives an account of his walk as represented by his running stitches on the canvas. Literarily, by drawing his walk on the canvas via the Running Stitch framework, the participant made his Self legible. However, nobody but the walker himself is in the position to make an authoritative reading of his walk. The terms “reading” and “legibility” refer in this context to the ability to both remember and make sense of one’s own steps. In this sense, the drawing—the trace of the walk—must be seen as a mnemonic device enabling the subject who walked to perform self-reading, hermeneutic acts. Disclosure, as illustrated by this case, is then linked with a self-reading process in terms of a walk—a spatio-temporal live process—as documented on the canvas.Certainly, the Self of the participant emerges as the theme of his map as drawn on the canvas: “I wanted to go past various landmarks…” Rather than space, it is the being-who-moves in space what is being read and mapped through self-reflexive language.According to Ervin Goffman’s dramaturgical approach to social interaction, the notion of presentation of Self takes relevance whenever an individual “enters the presence of others” (14). To be in the presence of others, whether wittingly or unwittingly, involves a presentation of Self. Goffman’s influential The Presentation of Self in Everyday Life (1959) is primarily concerned with arguing that the ways in which one presents the Self may direct the interlocutors’s attention towards those aspects of the Self one chooses to highlight (14). A premise underlying Goffman’s work is that a presentation of Self generates impressions and that one can manage the impressions one makes of oneself. A crucial concept in his theory is the notion of control: one can control and guide the other’s impressions of oneself, and a number of techniques can be employed to do so. It is crucial to understand that in practices such as Running Stitch, participants are enabled to occupy a dual position as “writers” and “readers” of the Self, as positioners and as the ones positioned. As “writers,” participants position themselves physically, graphically and literally both in the city and “on the map.” This takes place by means of a walking-drawing performance via GPS technology. As “readers”, participants position themselves linguistically (by means of autobiographical stories) and in their mind in relation with the performed space in question.By presenting his walk with words as ‘a walk for a friend of mine—Sandra—who’s very ill’, this participant positions himself subjectively in relation to his performed walk. His auto-biographical narrative infuses his walk with meaning. There is a relatively new approach in social psychology called “positioning theory” (Harre and Slocum). Drawing on Goffman’s work on social interaction, the issue that this theory investigates is the dynamics of creation of patterns of meaning. How can these dynamics be brought to light?Positioning theory analyses the emergence of meaning in terms of story lines. It is concerned exclusively with analysis at the level of acts; that is, of the meaning of actions as expressed through story lines that infuse those actions with meaning. A positioning is not a theoretical knowledge about one’s relationship with a given space. Rather, it is a practised knowledge. Moreover, it is an act of freedom. It is a choice. And it is an ethical choice in the sense that the one who positions himself claims responsibility for his own acts and decisions. The “I” of the one who positions himself emerges as the actor, author, and theme of the narratives that go with that decision. Such an act writes subjectivity (biography). Paraphrasing philosopher Emmanuel Lévinas, a reflexive positioning is a disclosure and opening of being that takes place for others and with others and where being manifests, loses, and finds itself again “so as to possess itself by showing itself, proposing itself as a theme, exposing itself in truth” (99). A reflexive positioning is a moment of truth. However, and still with Lévinas, truth, “before characterizing a statement or a judgment, consists in the exhibition of being” (23). In other words, by presenting the self in public and in spatio-temporal terms, the subject who presents herself produces truth about herself as a relational and spatial being.Positioning, or the Enactment of a Poetics of SharingI use the term sharing as the act of presenting private, subjective, everyday life, and autobiographical material in public contexts. My notion of the term sharing is inspired by Deirdre Heddon’s (21) account of how consciousness-raising events in which women shared personal concerns with each other was tied with the emergence of feminist, autobiographical live performances. In the context of such feminist events, according to Heddon, sharing and consciousness-raising processes were linked.My argument is that, in a similar fashion to feminist’s consciousness-raising events, the “knowledge” that the representations (maps) claim to represent in practices such as Running Stitch cannot be achieved if the voices behind the trajectories are not activated. The transformation of the represented trajectory into self-mapping knowledge cannot be achieved if the individual who took part does not “read” herself by sharing her spatial autobiographical narrative with others. For such a self-mapping to take place, artists need to devise a mechanism for participants to share reflections about their participation experience and embed it in the framework they provide. I use the word poetics as synonymous with the notion of “technology” as articulated by Martin Heidegger in his 1955 lecture on the question of technology. A poetics is “a way of revealing truth” (qtd. in McKenzie 156). In this sense, “participation cartography” is a technology that enables participants to bring forth “truth” (rather than simply disclose truth) about their self as a being-in-motion. However, it is a way of revealing that also conceals. This is precisely what makes this way of revealing a poiesis: it reveals and conceals at once. For instance, the uniqueness of my Running Stitch walk was concealed to me. I walked with my wife, our son, and a couple of friends who lived in Brighton at that time. Our walk was a means for us to spend some time together. In a way, it was a means for building our relationship. The meaning of our walk became conscious to me after I had read the story of Sandra’s friend and the other ninety or so stories. Without these (collective) conversations and exchanges, the disclosures made by participants in and through ‘participation performances’ such as Running Stitch conceal more than what they reveal, shattering thereby the cartographic (self-mapping) power of these practices.The act of validating the sequence of stitches as his is a crucial performative element of this process. It completes the disclosure process: it is the moment in which the voiceless walker on the canvas becomes a speaking subject who authors himself by recognising himself in the uniqueness of his auto-bio-graphical stitch. His spatial autobiographical narrative is a crucial self-positioning performance. By not framing moments of sharing such as this as integral to the cartographic process, I suggest that the artist may scatter the self-mapping and self-positioning agency of this practice. In consequence, the representation loses sight of what it claims to seek and represent. ReferencesEco, Umberto. 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Janet Abrams and Peter Hall. Minneapolis: University of Minnesota Design Institute, 2006.Kanarinka, “Art-Machines, Body-Ovens and Map-Recipes: Entries for a Psychogeographic Dictionary.” Cartographic Perspectives 53 (2006): 24–40.Kaprow, Allan. “Participation Performance.” Essays on the Blurring of Art and Life. Ed. J. Kelley.. Berkeley, Los Angeles, New York: University of California Press, 2003.Kaye, Nick. Site-Specific Art: Performance, Place, and Documentation. London: Routledge, 2000.Lévinas, Emmanuel. Otherwise than Being, or, Beyond Essence. Trans. Alphonso Lingis. Pittsburgh: Duquesne UP, 2006.McKenzie, Jon. Perform or Else: From Discipline to Performance. London: Routledge, 2001.“My walk was an act of love.” Unpublished anonymous participant's feedback sheet. Running Stitch. Jen Southern and Jen Hamilton. Brighton, U.K.: Fabrica Contemporary Art Gallery, 2006.Running Stitch. Jen Southern and Jen Hamilton. Brighton, UK.: Fabrica Contemporary Art Gallery, 2006. Sant, Alison. “Redefining the Basemap.” TCM Locative Reader (2004). 16 Jan. 2007 < http://locative.net/tcmreader/index.php?mapping;sant >.Wood, Denis. “Map Art.” Cartographic Perspectives: Journal of the North American Cartographic Information Society 53 (2006): 5–14.