• Journal of the Korean institute of surface engineering
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• v.55 no.5
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• pp.284-291
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• 2022

Herein, we studied ultrathin Cu-layer-based transparent heaters embedded between a ZnO underlayer and an Al₂O₃ overlayer. The anti-reflecting functions for the ZnO and Al₂O₃ layers by independently varying the layer thicknesses, with the Cu layer thickness fixed at 8.5 nm. The smallest visible light transmittance of 11.1% was achieved when the overlayer and underlayer thicknesses were 90 and 30 nm, respectively. We conducted electrically driven Joule heating test for the Cu layers having thicknesses of 8.5 nm (R_s: 14.7 Ohm/sq.) and 19 nm (R_s: 3.4 Ohm/sq.). External voltages were increased with an interval of 2 V until irreversible failures occurred at temperatures of ~390 ℃ and 550 ℃, respectively. At each voltage increase before heater failures, the heater exhibited superior thermal response with the heater temperatures reaching over 90% of the final temperatures. The heaters also showed excellent reproducibility when turning on and off the heater repeatedly.

• The Journal of Korean Society for Radiation Therapy
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• v.12 no.1
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• pp.144-146
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• 2000

삼차원 입체조형치료는 정상조직의 장해를 최소화하고 종양부위에 집중적으로 조사할 수 있는 장점을 가지고 있어 임상 적용범위가 넓어지고 있다. 일반적으로 정상조직의 장해를 줄이기 위해 다양한 방사선 조사방향이 사용되며 특히 비 동일면상에서의 조사가 많이 이루어진다. 따라서 couch 회전이 동반되며 couch는 선형가속기의 다른 기계적 오차보다 많은 오차를 유발할 수 있는 잠재적인 위험을 안고 있다. 저자는 이러한 오차의 정도를 파악하고 이를 개선할 수 있는 방법에 대해 알아보고자 했다. couch 회전에 따른 Isocenter의 변화를 평가하기 위해 3대(Primus, Simens, USA/CL600c & 2100c, Varian, USA)의 선형가속기를 이용하였으며 이중 1대의 장비에는 couch 회전시 오차를 줄이기 위해 고안된 couch 고정장치를 장착하였다. 환자가 테이블에 부하를 주지 않은 상태에서 회전을 실시하여 Isocenter의 변화를 측정하고 환자가 테이블에 누워있는 상황을 재현하기 위해 human phantom을 위치시킨 후 동일한 회전검사를 실시하여 각각의 오차를 비교 분석하였다. 각 실험은 10회씩 반복 측정하여 평균치를 얻었으며 오차의 분석은 AAPM 권고안인 오차중심의 반경으로 표현했다. 3대의 선형가속기를 이용하여 얻은 결과 테이블에 부하를 주지 않은 상태의 회전오차는 평균 2mm, 3.2mm, 2mm로 측정되었으며 휴먼 phantom을 올려놓고 부하를 준 상태에서의 오차는 평균 2.1mm, 4mm, 2.1 mm이였다. 또한 고정장치를 이용한 상태에서의 평균오차는 1.9mm로 나타났다. 삼차원 입체조형치료 시 couch 회전에 따른 Isocenter 오차는 장비의 종류 및 작업자의 사용방법에 따라 다르게 나타났으며 테이블의 부하가 클수록 많은 오차를 보였다. 또한 couch 고정장치를 부착한 장비에서의 결과치 만이 AAPM에서 권고하는 오차의 한계에(${\le}2mm$) 들어감을 알 수 있었다. 따라서 정기적인 QA가 필수적이며 Couch Locking System과 같이 오차를 줄일 수 있는 보조장치의 부착이 많은 도움을 줄 것으로 생각된다. 아울러 이러한 오차를 보정할 수 있는 방법이 강구되어야 할 것으로 사료된다.

• Journal of Korean Medical classics
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• v.19 no.4
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• pp.27-61
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• 2006

수당오대적대근의학발전유소적정책(隨唐五代적代근의學발展有소的政策), 기구(기구), 제도등축점완비료(制度等逐漸完비了). 저시기유정부발전의학교육적정책치득의정적공적(저時期由政府발展의學교育的政策値得의政的功적). 정규의학교육적방면상몰치전과의(定規의學교育的方面上몰置전科의), 안배교육과정(安排교育과程), 임용고시등구비구비료의학교적규모(任用考시等具비具비了의學교的規模), 영외발전료지방의학교육화의학보급(영外발展了地方의學보育和의學普及). 방포의방화지방요로상다착처방적조시백성의료제공방변(방布의方和地方要路上다着처方的조百姓의료提供方便), 야영향료의학화신적보급(也影향了의學和신的普及). 저시기의정상최현저적성과시제고본초학적지위적(저時期의政上最현著的成果是提高本草學的地位的). 태의서내설치료의학교육동시설치료전문약학교육(太의署內設置了의學교育同時설置了전문葯學교育). 이차정부이편수본초학적병반포전국위최초적약전(而且政府以編수本草學籍幷반布全국위最初的葯典). 저시기유정부법제화료의약관리방면적야시대대수획(저時期由政府法制化了의葯管理方面的也是大大收획). 수당이전몰형성의약관리화유소제도(隨唐以前沒形成의葯管理和有소制度), 규모(規模). 의생근거일정적법률근환자관계병엄가구관자기(의生根据一定的法律근患者관系幷엄可拘管自己). 수당오대의정흔다방면상탁유성효(隨唐五代의政흔多方面上卓有成效), 단시궁정의약기구적규모흔방대(但是宮廷의葯기구的規模흔방大), 인원과잉(人員과剩), 역궁정의관수공제(亦宮廷의官受控制), 불능발휘자기적능력(不能발揮自己的能力). 야불능발전위백성적의약기구(也不能발展위百姓的의葯기구). 인위정부불태중시의학(因위政府不太重시의學), 소이의생적지위잉시불고(所以의生的地位仍是不高). 나취시저시기의정적결점(那就是저시期의政的缺点).

• The Journal of the Acoustical Society of Korea
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• v.23 no.4
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• pp.323-332
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• 2004

Sound localization can be controlled by simulating the transfer functions from sound source to listener's ears. Even by using this method. a good performance cannot be expected when a listener slightly moves from the position where the transfer functions were measured. We have already been proposed the multi-point control method to overcome the problem of the listener's small movement. In this method, the transfer functions are simulated at multiple points around the listner's ears so that the points forms an area which covers the small movement of the listener. In this paper. we investigated the effect of applying multi-point control method for the control of sound localization. Results show that multi-point control is effective to keep the perceptual error of the localized direction small when the listener moves up to 6 cm from the original position.

• The Journal of the Acoustical Society of Korea
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• v.23 no.4
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• pp.324-324
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• 2004

Sound localization can be controlled by simulating the transfer functions from sound source to listener's ears. Even by using this method. a good performance cannot be expected when a listener slightly moves from the position where the transfer functions were measured. We have already been proposed the multi-point control method to overcome the problem of the listener's small movement. In this method, the transfer functions are simulated at multiple points around the listner's ears so that the points forms an area which covers the small movement of the listener. In this paper. we investigated the effect of applying multi-point control method for the control of sound localization. Results show that multi-point control is effective to keep the perceptual error of the localized direction small when the listener moves up to 6 cm from the original position.

• Journal of Korean Society of Forest Science
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• v.31 no.1
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• pp.37-42
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• 1976

In this study, an effort was made to find out more effective methods for vegetation establishment on denuded forest land along Cheon Bo Mountains, This area has serious sheet erosion as a major erosion process and parent material is granite gneiss which is known as one of the most erosive materials. Lespedeza bicolor, Arundinella hirta and Robinia pseudoacacia were used as ground cover species. Seeding methods were open broadcast seeding and broadcast seeding with straw mulch, dill seeding with 10cm and 20cm width, and spot seeding with 20cm and 30cm diameter. 1. On slopes less than 30 degrees, broadcast seeding method with straw mulch was the most effective way to establish vegetation cover. 2. On steep slopes more than 30 degrees, 10cm drill seeding method was more effective than the other methods. 3. Soil Texture has an influence on vegetation establishment governing soil moisture condition. Coverage and fresh weight were increased with the fine material qantity in soil. 4. In process of year, coverage was increased with fresh weight. On the other hand, survival decreased.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.151-153
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• 2010

In this paper, the tri-band planar monopole microstrip antenna which stimulaneously meets the three bands such as TRS, WLAN and DMB is designed. The designed antenna size was smaller using CPW-fed structure that shows a ground-plane and a patch-plane are existed at one layer. The proposed antenna is designed on FR-4 substrate with a relative dielectric constant 4.3, thickness of 1.5mm and tangent loss 0.04. The designed antenna shows that VSWR is below 2 and has good return loss below -10dB over the three bandwidths.

• Journal of Korean Foot and Ankle Society
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• v.10 no.1
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• pp.56-59
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• 2006

Purpose: The purpose of this study is to find out the normal distal tibial articular surface angle in coronal plane in Koreans. This would be helpful as the basic data for ankle reconstruction after trauma or deformity correction. Materials and Methods: Weight bearing anteroposterior radiographs of 123 normal ankles were reviewed. A line parallel to the shaft of the tibia was made. Another line was drawn parallel to the articular surface of the distal tibia. The superolateral angle that subtended by these two lines was measured. Results: There were 72 males and 51 females. The mean age overall was 35.7 years old. The mean age for males was 31.9 ($28{\sim}36$) years old. The mean age for females was 41.1 ($37{\sim}45$) years old. The mean distal tibial articular surface angle was $90.8^{\circ}$. The mean distal tibial articular surface angle for males was $91.5^{\circ}$ and for females $89.9^{\circ}$. Conclusion: The mean distal tibial articular surface angle in coronal plane for Koreans is $90.8^{\circ}$. We can avoid the error of the varization at the ankle alignment when the correction was performed vertical or minimal valgus to tibia tuberosity axis in Korean people.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.1000-1006
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• 2006

In this paper, the gain of the square hem antenna is enhanced with $3{\times}3$ latticed aperture. In order to get the uniform field distribution on the aperture, the different thicknesses of dielectric plates for the phase compensation are inserted into the center and the edge of the aperture respectively. The proposed horn antenna is designed at 12.5 GHz band, and then the analysis of the field distribution on the aperture is performed by using FDTD method. The radiation pattern is also calculated from the analysis. Based on the measured data, it is verified that the gain of a horn antenna with latticed aperture is 18 dBi and this is 2 dB gain enhancement compare with a normal horn antenna without latticed aperture.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.2015-2025
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• 1991

A long and light-weight forearm of the vertical 2 DOF robot manipulator with a heavy payload driven by parallel drive mechanism is modelled as a Euler-Bernoulli beam with a tip mass subjected to a high speed rotation. Governing equation is obtained by Hamilton's principle and represented as state variable form using the perturbed variables which describe the perturbed errors at the manipulator's final configuration. Digitial optimal control and observer theory are used to suppress the forearm vibration and control the positions of the joint angles with measured/estimated state feedback. Computer simulations and experimental results are obtained and compared each other.