• 한국HCI학회:학술대회논문집
• /
• 2007.02b
• /
• pp.1-6
• /
• 2007

최근 다양한 기기와 환경에서 문자 입력에 대한 요구가 높아지고 있다. 이에 따라 효율적인 문자 입력 인터페이스 설계를 위해 문자 입력 인터페이스의 평가가 필요한 실정이다. 기존 연구를 살펴보면 문자 입력 시간을 시각 탐색 시간과 손가락 이동 시간으로 나누고 정보처리 이론인 Hick-Hyman Law와 Fitts’ Law를 통해 예측, 평가 하였다. 하지만 위 두 과정은 연속적(serial)인 과정으로 눈과 손의 coordination(협응)에 대해 관과 하는 한계가 있다. 또한, 기존 문자 입력 시간 예측 모델은 전문가라는 특정 숙련도를 가정하고 만들어졌기 때문에 실제 문자 입력 시간에 비해 과대 측정되어 왔다. 이에 본 연구는 문자 입력 시간 예측 모델에 눈-손 coordination 매개변수를 삽입하고자 눈-손 coordination의 시간을 측정하고 행태를 분석하였다. 또한, 비숙련자와 숙련자의 구분을 통해 시각 탐색 시간과 손 움직임 시간 그리고 눈-손 coordination의 시간 과 행태가 어떻게 변화하는 지 분석하였다. 그 결과 눈-손 coordination 시간은 문자 입력 시간과 밀접한 관계가 있었다, 그리고, 눈-손 coordination 시간은 숙련도에 상관없이 문자 입력 시간의 22%를 차지하였다. 또한, 숙련자와 비숙련자의 문자 입력 시간과 비교해 손과 coordination 시간 비율은 차이가 없었다. 하지만, 눈의 움직임 시간 비율은 큰 차이를 나타내었다. 이 결과는 눈-손 coordination과 숙련도 차이를 기존 문자 입력 예측 모델에 매개변수로써 적용하기 위한 기초 자료가 될 것이다.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.225-227
• /
• 2005

The in-core neutron Flux Mapping System in a pressurized water reactor yields information on the neutron flux distribution in the reactor core at selected core locations by means of movable detectors. The obtained data are used to verify the reactor core design parameters. The detector cables run through guide tubes(thimbles), and typically thirty-six to fifty-eight thimbles are allocated in the reactor depending on the number of fuel assemblies. These thimbles are inserted into nuclear fuel assemblies through conduits connected from the bottom of the reactor vessel to a seal table. During the plant refueling outage period, the thimbles are withdrawn up to 4m from the seal table, the height of a nuclear fuel. In spite of their importance, however, the thimble handling work has been performed by only human operators. In addition, its efficiency is very low due to narrow working environments on the seal table, thereby resulting in the excessive radiation exposure of maintenance personnel. To solve these problems, a new thimble handling equipment for in-core flux mapping system was developed, and we confirmed its effectiveness through experiments.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.172-172
• /
• 2011

현대 반도체 금속배선 연구에서는 기존에 쓰이던 Al (Aluminium) 금속배선 대신에 Cu(Copper) 금속배선 연구가 진행 되고 있다. Cu는 Al 보다 비저항이 낮고, 녹는점도 Al보다 높다는 장점이 있지만 저온에서 기판인 Si (Silicon) 과 반응하고 접착력이 우수하지 못 하다는 단점이 있다. 이런 문제를 해결하기 위하여 확산방지막을 기판과 금속배선 사이에 삽입하는 방법이 제시 되었다. 확산방지막으로는 기존에 쓰이던 Ti (Titanium) 계열의 확산방지막과 W (Tungsten) 계열의 확산방지막이 있다. 이번 연구에서는 W 계열의 확산방지막에 불순물 C (Carbon), N(Nitrogen)을 첨가한 W-C-N 확산방지막 시편을 제조하였고, N2의 비율을 변화시키며 $600^{\circ}C$ 열처리를 하였다. 실험 결과 질소의 포함 농도에 따라 확산방지막의 안정도가 변화한다는 결과를 얻었으며, 질소 첨가량에 따라 시편의 표면 보다는 시편의 중간층의 물성 변화율이 큰데 이는 시편 표면의 질소는 열처리 중 확산에 의한 시편과의 분리 현상이 일어나지만 시편의 중간층은 trap현상에 의하여 시편에 남아있어 질소의 영향을 받아 시편의 중간층이 더욱 질소 유량에 따른 영향이 큰 것을 확인하였다. 이 결과로부터 W-C-N 박막은 첨가된 질소의 유량에 따라 박막의 안정도가 결정된 다는 것을 알았다. 본 연구에서 시편은 rf magnetron sputtering 방법으로 제작하였고 연속압입 실험은 Hysitron사의 Triboindenter를 이용하였다. Indenting에 사용된 압입팁은 Berkovich tip을 사용하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.10
• /
• pp.1048-1053
• /
• 2002

In this paper, thin film bulk acoustic resonator(TFBAR) lattice and balanced type filter topologies are designed and fabricated. Aluminium nitride and platinum are used for piezoelectric material and top and bottom electrodes, respectively. Air-gap is placed to avoid silicon substrate loading effect and the performance of these lattice and balanced filters is compared with ladder filters. These filters have selectivity over 15 dB for lattice type and 30 dB for balanced type and reveal wider bandwidth of the ladder filters. For balanced type filters, minor tuning procedure is not needed and they are readily available for RF filter in wireless applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.6
• /
• pp.528-537
• /
• 2002

In this paper, the extended FDTD is used for the analysis of microwave circuits including active elements. Lumped elements such as R, L, C which are inserted into a microstrip line are analyzed with the FDTD lumped element modeling. Parasitic capacitance and inductance could be obtained using network modeling and so it is sure that FDTD lumped element modeling makes it possible to get more accurate data which include parasite components. Moreover, a balanced mixer using two diodes that are modeled by an extended FDTD is designed and the more exact characteristic of the mixer is acquired than in current circuit simulator.

• Journal of Chest Surgery
• /
• v.30 no.11
• /
• pp.1142-1144
• /
• 1997

A case of fatal hematemesis due to an aberrant right subclavian arterioesophageal fistula which is a rare complication of the vascular ring is presented. A 42-year-old man with multiple injury by traffic accident presented severe upper gastrointestinal bleeding and was taken emergent operation. He was keeping tracheostomy tube and nasogastric tube for 7 weeks. We could find an aberrant right subclavian arterioesophageal fistula through left thoracotomy which was made by irritation of the prolonged nasogastric ube. We carried division of the aberrant right subclavian artery and fistulectomy. He was doing well postoperatively. But massive bleeding occurred at the fifth postoperative day. We performed emergent reoperation at CCU and found the tear point on the suture site of the aorta, which might be developed due to irritation of the chest tube andfor infection of the surrounding tissues. He was expired at the 8th postoperative day due to ischemic brain damage.

• Journal of the Korean Institute of Gas
• /
• v.11 no.4
• /
• pp.35-40
• /
• 2007

In this paper, evaporation heat transfer characteristics of propane and iso-butane in micro-fin tubes were investigated experimentally. Test section has a micro-fin tube with outside diameter of 12.70 mm, and 75 fins with a fin heights of 0.25 mm. The experimental results summarize as the followings: The average evaporation heat transfer coefficients of He's refrigerants is higher than those of HCFC22, and appeared in the order of iso-butane, propane with respect to the approaching of the high mass flux. The evaporation heat transfer coefficient of micro fin tube is about $10{\sim}80%$ higher than those of smooth tube. This results from the study can be used in the case of designing heat transfer exchanger using hydrocarbons as the refrigerant for the air-conditioning systems.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.2
• /
• pp.79-84
• /
• 2009

Turbocharger has been widely used in many passenger cars in application with diesel engines because of high power and fuel efficiency. However, flow-induced noise (whoosh or hissing noise) which is generated within a compressor during its operation at marginal surge line can deteriorate noise characteristics. Hissing noise excitation is associated with the generation of turbulence within the turbocharger compressor and radiated through the transmission path in a turbocharger system. In this study, a expansion muffler with lids is devised and installed in the transmission path to reduce the hissing noise. Acoustic and fluid dynamic characteristics for the muffler are investigated which are related to the unsteadiness of turbulence and pressure in the turbocharger system. A transfer matrix method is used to analyze the transmission loss of the muffler. A simple expansion muffler with lids is proposed for the reduction of high frequency component noise. Turbulence simulation is carried out by a standard k - ${\varepsilon}$ model. An optimal design condition of the muffler is obtained by extensive acoustic and fluid dynamic analysis on the engine dynamometer with anechoic chamber. A significant reduction of the hissing noise is achieved at the optimal design of the muffler as compared with the conventional muffler.

• Korean Journal of Ichthyology
• /
• v.23 no.2
• /
• pp.106-110
• /
• 2011

Fine structure of spermatozoa of the bastard halibut (Paralichthys olivaceus) is described. Its structure is characterized by acrosomeless, having a spherical head region and a small mid piece containing five mitochondria disposed one row. The flagellum inserts centrally on the nucleus and has lateral ribbons. The present study supports the suggestion that spermatozoal ultrastructure is of taxonomic importance and may be a phylogenetic criterion in teleostei.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.12 s.255
• /
• pp.1509-1517
• /
• 2006

The intervertebral fusion was reported to increase the degeneration of the neighboring region. Recently, a new technique of inserting an interspinous process fixator has been introduced to minimize the degenerative change in the lumbar spine. This study analyzed biomechanical effects of the fixator in the lumbar spine, and designed a new prototype to improve flexibility of the fixator with a reduced size. The evaluation was based on the displacement, stiffness and von-Mises stress obtained from the mechanical test and finite element analysis. A finite element lumbar model of L1 to L5 was constructed. The finite element model was used to analyze intervertebral fusion, insertion of a commercial fixator and a new prototype. The range of motion of intervertebral segments and pressures at vertebral discs were calculated from FEA. The results showed that the stiffness of the prototype was reduced by 32.9% than that of the commercial one.