• Journal of Radiation Industry
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• v.6 no.1
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• pp.31-40
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• 2012

There are two methods to fabricate the readout electronic to a large-area CMOS image sensor (LACIS). One is to design and manufacture the sensor part and signal processing electronics in a single chip and the other is to integrate both parts with bump bonding or wire bonding after manufacturing both parts separately. The latter method has an advantage of the high yield because the optimized and specialized fabrication process can be chosen in designing and manufacturing each part. In this paper, LACIS chip, that is optimized design for the latter method of fabrication, is presented. The LACIS chip consists of a 3-TR pixel photodiode array, row driver (or called as a gate driver) circuit, and bonding pads to the external readout ICs. Among 4 types of the photodiode structure available in a standard CMOS process, $N_{photo}/P_{epi}$ type photodiode showed the highest quantum efficiency in the simulation study, though it requires one additional mask to control the doping concentration of $N_{photo}$ layer. The optimized channel widths and lengths of 3 pixel transistors are also determined by simulation. The select transistor is not significantly affected by channel length and width. But source follower transistor is strongly influenced by length and width. In row driver, to reduce signal time delay by high capacitance at output node, three stage inverter drivers are used. And channel width of the inverter driver increases gradually in each step. The sensor has very long metal wire that is about 170 mm. The repeater consisted of inverters is applied proper amount of pixel rows. It can help to reduce the long metal-line delay.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2150-2158
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• 1992

This study was carried out to investigate the flow structure and mixing process of a cross mixing flow formed by two round jets with respect to the ratio of mass flow rate. This flow configuration is of great practical relevance in a variety of combustion systems, and the flow behaviour of a cross jet defends critically on the ratio of mass flow rate and the cross angle. The mass flow rate ratios of two different jets were controlled as 1.0, 0.8, 0.6, and 0.4, and the crossing angle of two round jets was fixed at 45 degree. The velocities issuing from jet nozzle with an exit diameter of 20mm were adjusted to 40m/s, 32m/s, 24m/s, and 16m/s, and the measurements have been conducted in the streamwise range of $1.1X_0$to $2.5X_0$ by an on-line measurement system consisted of a constant temperature type two channel hot-wire anemometry connected to a computer analyzing system. The original air flow was generated by a subsonic wind tunnel with reliable stabilities and uniform flows in the test section. For the analysis of the cross mixing flow structure in the downstream region after the cross point, the mean velocity profiles, the resultant velocity contours, and the three-dimensional profiles depending upon the mass flow rate ratio have been concentrately studied.

• Tunnel and Underground Space
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• v.14 no.1
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• pp.54-68
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• 2004

In this study, scaled model tests were performed on blasting demolition of reinforced concrete structures and the experimental results were analyzed in comparison with the results of numerical analysis. The tests were designed to induce a progressive collapse, and physical properties of the scaled model were determined using scale factors obtained ken dimension analysis. The scaled model structure was made of a mixture of plaster, sand and water at the ratio determined to yield the best scaled-down strength. Lead wire was used as a substitute for reinforcing bars. The scaled length was at the ratio of 1/10. Selecting the material and scaled factors was aimed at obtaining appropriately scaled-down strength. PFC2D (Particle Flow Code 2-Dimension) employing DEM (Distinct Element Method) was used for the numerical analysis. Blasting demolition of scaled 3-D plain concrete laymen structure was filmed and compared to results of numerical simulation. Despite the limits of 2-D simulation the resulting demolition behaviors were similar to each other. Based on the above experimental results in combination with bending test results of RC beam, numerical analysis was carried out to determine the blasting sequence and delay times. Scaled model test of RC structure resulted in remarkably similar collapse with the numerical results up to 900㎳ (mili-second).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.495-500
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• 2006

Satellite systems for objects positioning appeared indispensable for performing basic tasks of maritime navigation. Navigation, understood as safe and effective conducting a vehicle from one point to another, within a specific physical-geographical environment. [Kopacz, $Urba{\acute{n}}ski$, 1998]. However, the systems have not solved the problem of accessibility to reliable and highly accurate information about a position of an object, especially if surveyed toward on-shore navigational signs or in sea depth. And it's of considerable significance for many navigational tasks, carried out within the frameworks of special works performance and submarine navigation. In addition, positioning precisely the objects other than vessels, while executing hydrographical works, is not always possible with a use of any satellite system. Difficulties with GPS application show up also while positioning such off-lying dangers as wrecks, underwater and aquatic rocks also other naturaland artificial obstacles. It is caused by impossibility of surveyors approaching directly any such object while its positioning. Moreover, determination of vessels positions mutually (mutual geometrical relations) by teams carrying out one common tasks at sea, demands applying the navigational techniques other than the satellite ones. Vessels'staying precisely on specified positions is of special importance in, among the others, the cases as follows: - surveying vessels while carrying out bathymetric works, wire dragging; - special tasks watercraft in course of carrying out scientific research, sea bottom exploration etc. The problems are essential for maritime economy and the Country defence readiness. Resolving them requires applying not only the satellite navigation methods, but also the terrestrial ones. The condition for implementation of the geo-navigation methods is at present the methods development both: in aspects of their techniques and technologies as well as survey data evaluation. Now, the classical geo-navigation comprises procedures, which meet out-of-date accuracy standards. To enable meeting the present-day requirements, the methods should refer to well-recognised and still developed methods of contemporary geodesy. Moreover, in a time of computerization and automation of calculating, it is feasible to create also such software, which could be applied in the integrated navigational systems, allowing carrying out navigation, provided with combinatory systems as well as with the new positioning methods. Whereas, as regards data evaluation, there should be applied the most advanced achievements in that subject; first of all the newest, although theoretically well-recognised estimation methods, including estimation [Hampel et al. 1986; $Wi{\acute{s}}niewski$ 2005; Yang 1997; Yang et al. 1999]. Such approach to the problem consisting in positioning a vehicle in motion and solid objects under observation enables an opportunity of creating dynamic and interactive navigational structures. The main subject of the theoretical suggested in this paper is the Interactive Navigational Structure. In this paper, the Structure will stand for the existing navigational signs systems, any observed solid objects and also vehicles, carrying out navigation (submarines inclusive), which, owing to mutual dependencies, (geometrical and physical) allow to determine coordinates of this new Structure's elements and to correct the already known coordinates of other elements.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.29-38
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• 2022

In this study, the shaking table tests were carried out on six types of non-structural elements installed on a full-scale two-story steel structure. The shaking table tests were performed for non-structural elements with and without seismic isolators. In this study, the seismic performance of Uninterruptible Power Supply (UPS) specimens was tested and investigated. Non-seismic details were composed of conventional channel section steel beams, and the seismic isolators were composed of high damping rubber bearing (HDRB) and wire isolator. The input acceleration time histories were artificially generated to satisfy the requirements proposed by the ICC-ES AC156 code. Based on the test results, the damage and dynamic characteristics of the UPS with the seismic isolator were investigated in terms of the natural frequency, damping ratio, acceleration time history responses, dynamic amplification factors, and relative displacements. The results from the shaking table showed that the dynamic characteristics of the UPS including the acceleration response were significantly improved when using the seismic isolator.

• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.303-312
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• 2004

An unfavorable tipping movement can occur during the retraction of anterior teeth because orthodontic force is loaded by brackets positioned far from the center of resistance. To avoid this unfavorable movement, a compensating curved wire or lingual root torque wire is used. The purpose of this study is to investigate, using photoelastic material, the distribution of initial stress associated with the retraction of the incisors according to the degree of the compensating curve, to model changes associated with tooth ud alveolar bone structure. The following results were obtained by analysis of the polarizing plate of the effects of initial stress resulting from retraction of the anterior teeth: 1. When the incisors were retracted using combination archwire or sliding mechanics, the maximal polarizing pattern of the apical area decreased as the degree of the compensating owe increased from 0 to 15 to 30. 2. When the incisors were retracted by the combination archwire or sliding mechanics, the maximal polarizing pattern of the canine and premolar area increased as the degree of the compensating curve increased from 0to 15to 30. 3. A lower degree of polarizing patterns were associated with the combination archwire technique than the sliding mechanics technique at a given force. The above results indicate that there is no significant difference between the combination loop archwire technique and sliding mechanics, for the retraction of maxillary anterior teeth with decreased lingual tipping tendency by a compensating curve on the arch wire. However, the use of sliding mechanics is more effective for the prevention of lingual inclination of the anterior teeth, because the hook used in sliding mechanics is closer to the center of resistance of the maxillary anterior teeth.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.9
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• pp.1260-1266
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• 2002

In this study, to make an excellent heat pipe, the manufacturing technology of a sintered wick was investigated. Making a sintered wick is known to be very difficult but it has many advantages. For example, the porosity and pore size can be controlled and the capillary force is great. The mixture of copper and pore former powder was used as a wick material and ceramic-coated stainless steel was used as a mandrel which is necessary for vapor flow. To analyze the feature of the manufactured wick, not only porosity and pore size were measured but also the sintered structure was observed. A heat pipe with sintered wick was manufactured and the performance test of the heat pipe was performed in order to review cooling performance. The performance test results for the 4mm diameter heat pipe with the sintered wick shows the stability since the temperature difference between a evaporator and a condenser of the heat pipe is less than 4.4$^{\circ}C$, and thermal resistance is less than 0.7$^{\circ}C$/W, In the meantime the composite wick that is composed with sintered and woven wire was also examined. The heat transfer limit of the heat pipe with composite wick was enhanced about 51%~60% compare to the one with sintered wick.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.11
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• pp.23-32
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• 2005

The automatic generation of circuit diagrams has been practically used in the HDL based design for decades. Nevertheless, the diagrams became too complicated for the designers to identify the signal flows in the RTL and system level designs. In this paper, we propose four techniques to enhance the roadability of the complicated diagrams. They include i) the transformation of repetitive instances and terminals into vector forms, ii) an improved loop breaking algorithm, iii) a flat tap which simplifies the two level bus ripping structure that is required for the connection of a bundle net to multiple buses, and iv) the identification of block strings, and alignment of the corresponding blocks. Towards validating the proposed techniques, the diagrams of an industrial strength design m generated. The complexity of the diagrams has been reduced by up to $90\%$ in terms of the number of wires, the aggregate wire length, and the area.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.8
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• pp.35-45
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• 1999

In this paper, the addition and the multiplicative algorithm of two polynomials over finite field $GF(p^m)$ are presented. The 4-valued arithmetic processor of the serial input-parallel output modular structure on $GF(4^3)$ to be performed the presented algorithm is implemented by current mode CMOS. This 4-valued arithmetic processor using current mode CMOS is implemented one addition/multiplication selection circuit and three operation circuits; mod(4) multiplicative operation circuit, MOD operation circuit made by two mod(4) addition operation circuits, and primitive irreducible polynomial operation circuit to be performing same operation as mod(4) multiplicative operation circuit. These operation circuits are simulated under $2{\mu}m$ CMOS standard technology, $15{\mu}A$ unit current, and 3.3V VDD voltage using PSpice. The simulation results have shown the satisfying current characteristics. The presented 4-valued arithmetic processor using current mode CMOS is simple and regular for wire routing and possesses the property of modularity. Also, it is expansible for the addition and the multiplication of two polynomials on finite field increasing the degree m and suitable for VLSI implementation.

• Current Photovoltaic Research
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• v.2 no.1
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• pp.1-7
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• 2014

We developed a method of growing thin Si film at $600^{\circ}C$ by hot wire CVD using a very thin large-grained poly-Si seed layer for thin-film Si solar cells. The seed layer was prepared by crystallizing an amorphous Si film by vapor-induced crystallization using $AlCl_3$ vapor. The average grain size of the p-type epitaxial Si layer was about $20{\mu}m$ and crystallographic defects in the epitaxial layer were mainly low-angle grain boundaries and coincident-site lattice boundaries, which are special boundaries with less electrical activity. Moreover, with a decreasing in-situ boron doping time, the mis-orientation angle between grain boundaries and in-grain defects in epitaxial Si decreased. Due to fewer defects, the epitaxial Si film was high quality evidenced from Raman and TEM analysis. The highest mobility of $360cm^2/V{\cdot}s$ was achieved by decreasing the in-situ boron doping time. The performance of our preliminary thin-film solar cells with a single-side HIT structure and $CoSi_2$ back contact was poor. However, the result showed that the epitaxial Si film has considerable potential for improved performance with a reduced boron doping concentration.