• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.436-436
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• 2011

Recently, spintronic devices with submicron structures are widely investigated to take advantage of their unique micromagnetic properties. In this work, we study the temperature dependence of exchange bias in bilayer anti-dot arrays made by depositing Co (40 nm)/Ni (5 nm) ferromagnetic bilayer on Si substrate to form anti-dot arrays with a diameter $1{\mu}m$. The anti-dot patterning was done only for the upper Co layer, while the Ni underlayer was kept unperforated. The temperature dependences of magnetoresistance (MR) and exchange bias were studied along magnetic easy and hard axes. The in-plane MR measurements were performed using a physical-property measurement system (PPMS ; Quantum Design Inc.) at various temperatures. The standard in-line four-point probe configuration was used for the electrical contacts. As temperature was varied, the MR data were obtained in which in-plane field (H=3 kOe) was applied in the directions along the hard and the easy axes with respect to the lattice plane. The temperature dependences of magnetic anisotropy and exchange bias were also studied along the magnetic easy and hard axes. As temperature decreases, the single peak splits into two peaks. While no exchange bias was observed along the magnetic easy axis, the exchange bias field steadily increased with decreasing temperature along the magnetic hard axis. These results were interpreted in connection with the magnetic anisotropy and the effect of the anti-dots in pinning domain wall motion along the respective direction.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.130-135
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• 2013

This study proposed a noble process to fabricate TSV (Through Silicon Via) structure which has lower cost, shorter production time, and more simple fabrication process than plating method. In order to produce the via holes, the Si wafer was etched by a DRIE (Deep Reactive Ion Etching) process. The via hole was $100{\mu}m$ in diameter and $400{\mu}m$ in depth. A dielectric layer of $SiO_2$ was formed by thermal oxidation on the front side wafer and via hole side wall. An adhesion layer of Ti and a seed layer of Au were deposited. Soldering process was applied to fill the via holes with solder paste and metal powder. When the solder paste was used as via hole metal line, sintering state and electrical properties were excellent. However, electrical connection was poor due to occurrence of many voids. In the case of metal powder, voids were reduced but sintering state and electrical properties were bad. We tried the via hole filling process by using mixing solder paste and metal powder. As a consequence, it was confirmed that mixing rate of solder paste (4) : metal powder (3) was excellent electrical characteristics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1933-1954
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• 2013

Multiple wireless devices are being widely deployed in Intelligent Transportation System (ITS) services on the road to establish end-to-end connection between vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) networks. Vehicular ad hoc networks (VANETs) play an important role in supporting V2V and V2I communications (also called V2X communications) in a variety of urban environments with distinct topological characteristics. In fact, obstacles such as big buildings, moving vehicles, trees, advertisement boards, traffic lights, etc. may block the radio signals in V2X communications. Their impact has been neglected in VANET research. In this paper, we present a realistic and efficient radio propagation model to handle different sizes of static and moving obstacles for V2X communications. In the proposed model, buildings and large moving vehicles are modeled as static and moving obstacles, and taken into account their impact on the packet reception rate, Line-of-sight (LOS) obstruction, and received signal power. We use unsymmetrical city map which has many dead-end roads and open faces. Each dead-end road and open faces are joined to the nearest edge making a polygon to model realistic obstacles. The simulation results of proposed model demonstrates better performance compared to some existing models, that shows proposed model can reflect more realistic simulation environments.

• Journal of Fashion Business
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• v.15 no.4
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• pp.1-15
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• 2011

Femme Fatale in Film Noir is a wicked woman character who seduces the male partner to a ruin. In the film, the dress style is of extreme importance for the personality creation of the character as well as the development of the plot. With this background, I have looked over the Femme Fatale dress style that appears in the movie . First, it expresses Femme Fatale which stresses the feminine trait by a dress style with enlarged chest and hip parts and long, slim silhouette with tight waist and knee line. Second, the Femme Fatale with pretended purity presents narcissistic satisfaction like a saint virgin by wearing a neck-high one-piece dress embellished with frills, but the use of mirror represents self-alienation and the vanity of purity. Third, the Femme Fatale with its military dress style presents authoritative sternness which leads seduced male into ruin with its destructive power. Fourth, wearing jersey type or knitted wear that sticks to the body presents sensual Femme Fatale. Fifth, the tulle, chiffon, and white handkerchief used for the creation of grotesque Femme Fatale represents harmlessness and prohibition of immoral behavior, and the black gloves, pillbox, and the number on the tulle present her uneasy psychological state from the fear of being discovered after murdering her husband. On the other hand, the see-through tulle presents alluring sensual beauty. Sixth, the combination of the dialogue in the final sequence and drapery type as in Greek goddess represents the saint virgin of salvation who acknowledges her own fault and returns to her purity again. In addition, accessories and others made from shining material represent hidden conspiracy through simple dress and contradictory dynamics, and shoes embellished with bonbon, etc represent sexual implications in connection with male.

• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.32-35
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• 2015

Many kinds of high temperature superconducting (HTS) devices are being developed due to its several advantages. In particular, the advantages of HTS devices are maximized under the DC condition. A line commutated converter (LCC) type high voltage direct current (HVDC) transmission system requires large capacity of DC reactors to protect the converters from faults. However, conventional DC reactor made of copper causes a lot of electrical losses. Thus, it is being attempted to apply the HTS DC reactor to an HVDC transmission system. The authors have developed a 8 mH class HTS DC reactor and a model-sized LCC type HVDC system. The HTS DC reactor was operated to analyze its operational characteristics in connection with the HVDC system. The voltage at both ends of the HTS DC reactor was measured to investigate the stability of the reactor. The voltages and currents at the AC and DC side of the system were measured to confirm the influence of the HTS DC reactor on the system. Two 5 mH copper DC reactors were connected to the HVDC system and investigated to compare the operational characteristics. In this paper, the operational characteristics of the HVDC system with the HTS DC reactor according to firing angle are described. The voltage and current characteristics of the system according to the types of DC reactors and harmonic characteristics are analyzed. Through the results, the applicability of an HTS DC reactor in an HVDC system is confirmed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4A
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• pp.377-384
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• 2006

According to fast VoIP technology development, more and more companies change voice network into IP based network among branch offices. IP PBX, which is deployed up to now, composed of IP phone and VoIP Gateway. Every telphone has replaced with If phone which support VoIP and VoIP gateway is installed in PBTN connection point to relay voice data. It can reduce the communication expense of International call, long distance call and call between a headquater and a trance because it uses internet line. In this paper, IP PBX is implemented that can distribute call using PBX network only usig personal terminal without Proxy Server. Depending on Role, terminal can be registered Master, Server and Client and it is verified in terms of performance and validation.

• The Korean Journal of Mycology
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• v.40 no.3
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• pp.177-178
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• 2012

Stem rot of perilla (Perilla frutescens var. japonica Hara) occurred sporadically in the exhibition field at Gyeongsangnam-do Agricultural Research and Extension Services in Korea. The infected stems are water-soaked, rotted, wilted and finally leads to the death of the whole plants. The sclerotia, 1-3 mm, white to brown, spherical, were formed on lesions and the surface of soil line. The optimum temperature for mycelial growth and sclerotia formation was $30^{\circ}C$ on potato dextrose agar and the hyphal width was 4-9 ${\mu}m$. The typical clamp connections were observed in the hyphae of the fungus. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of stem rot on perilla caused by S. rolfsii in Korea.

• Journal of Korea Ship Safrty Technology Authority
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• no.7 s.25
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• pp.47-63
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• 2008

저항성능 측면에서 한국 어선선형의 특성을 파악하기 위하여, 본 연구에서는 한국과 일본에서 건조되어진 대표적인 어선을 한 척씩 선정하여 두 어선의 선형적 특성을 비교하였다. 또한 한국 어선의 선형적 특성들, 즉 일부 대표적인 선형요소들과 이를 제외한 기타의 국부적 선형특성들을 일본어선의 선형을 참고로 보정함으로써 우리나라 어선들의 저항성능을 향상시킬 수 있는 방안에 대하여 연구하였다. 한국어선과 일본어선은 해양환경과 어업의 종류가 다를 뿐만 아니라 관습적인 이유 등으로 선형의 차이가 있게 되며, 이것은 한국 어선이 일본 어선에 비하여 같은 배수량을 가지더라도 배 길이가 짧은 반면 폭이 넓으며 흘수가 얕은 대표적인 선형요소들의 차이로 확인할 수 있다. 이러한 차이를 고려하여, 일본어선들에 대한 유효마력 추정프로그램을 한국어선들에 맞게 보정.개발하는 과정을 통하여 양국 어선의 저항성능 차이를 확인할 수 있었으며, 보정된 프로그램을 이용하여 연구대상의 한국어선에 대한 저항저감효과를 줄 수 있는 선형요소들을 도출함으로써 선형요소들의 변화에 따른 저항성능 효과를 확인할 수 있었다. 그러나 선형요소들의 보정에도 불구하고 한국어선의 저항성능은 여전히 일본어선의 그것보다 떨어짐을 확인하여, 본 연구에서는 대표적인 선형요소들뿐만 아니라 국부적 선형특성 즉, 선수부에서 차인선(chine line) 경사도, 용골의 형상, 선미길이(용골 끝에서 선미단까지의 거리)를 각각 보정해 봄으로써 보다 더 큰 저항성능의 개선효과를 확인하였다. 본 연구결과는 앞으로 저항성능이 우수하면서도 실용 가능한 개량된 한국 어선선형의 개발에 기초적인 자료로서 활용이 가능할 것으로 사료된다.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2303-2315
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• 2008

Finally, Musan-Bongdong section in Kyeong-Ui corridor opened on 11. DEC.2007, which is a historical event, because this connection means the restoration of 56 yrs' disconnection since 1951 and also starting point launching to connect china, Mongolia, Russia for continental railway logistic infrastructure. This is also one of master plans about the northern line in TAR, carried out by UNESCAP, so this study will touch up each country's railway status and the next tasks related with trans-continental railway such as North Korea, Russia, China. Also, this study reveal a mid-long term development strategy to improve the North Korea railroad for a continent rail link and international railroad transportation between China and Russia, and also checks the way of confrontation to the domestic infrastructure for the activation of the continent railway and the north and south, investigates concretely how to establish TAR northern part routes as soon as possible.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.457-464
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• 2009

The now velocity distribution at inlet of diesel Particulate filter (DPF) which is connected to each curved duct was simulated using $STAR-CD^{(R)}$. Three kinds of models which describe the shapes of the curved duct ware used for the CFD simulation. The simulation results were compared with the experimental data of velocity distribution which was obtained using a Pitot tube and 2-D positioning machine. At the $90^{\circ}$ curved connecting condition, the CFD simulation results of flow velocity distribution at inlet of the DPF showed a horse hoop shape shifted from the axial center line of the DPF. The CFD simulation results agree reasonably with those of the experiments.