• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.643-647
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• 2007

Purpose: The purpose of study was to investigate the correlationship between lip canting change and occlusal canting change after bimaxillary orthognathic surgery, and the ratio of lip canting change and occlusal canting change after the surgery. Patients and methods: The subjects for this study was obtained from a group of 25 patients who took bimaxillary orthognathic surgery for occlusal canting correction at the Department of the Oral and Maxillofacial Surgery, Samsung Medical Center in Seoul, Korea between January 2000 and December 2005 and a patient's chart had to contain a resting frontal facial photograph in natural head position and a corresponding PA cephalogram in occlusion on the same day before the surgery and post-op 6 months later. The lip canting change was assessed with the angle each labial commissure and the bipupilary reference line. And, the occlusal caning change in the frontal plane was assessed with the angle between the each maxillary first molar occulasal surface and the bi-frontozygomatic suture reference line. Results: In angular measurement, average occlusal canting change was $3.09^{\circ}$ and standard deviation was $1.05^{\circ}$, average lip canting change was $1.56^{\circ}$ and standard deviation was $1.05^{\circ}$. In linear measurement, average occlusal canting change was 2.41mm and standard deviation was 2.75mm, average lip canting change was 1.18mm and standard deviation was 0.43mm. Lip canting correction ration to occlusal canting correction was 51.5(${\pm}8.4$)% in angular measurement and 48.8(${\pm}9.1$)% in linear measurement. Under Pearson's correlation analysis, Pearson's correlation coefficient was 0.869 in angular measurement and 0.887 in linear measurement(p-value < 0.01). High correlationship was shown between occlusal canting change and lip canting change. Conclusion: First, Bimaxillary orthognathic surgery can correct lip canting as well as occlusal canting. Second, The average amount of lip canting correction is $51.5{\pm}8.4%,\;48.8{\pm}9.1%$ of occlusal canting correction in the study.

• 한국전자파학회논문지
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• 제22권9호
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• pp.897-903
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• 2011

본 논문에서는 InGaP/GaAs hetero-junction bipolar transistor(HBT)를 이용하여 900 MHz에서 동작하는 1 W급 선형 전력 증폭기를 설계 및 검증하였다. 온도 변화에 따른 증폭기의 특성 변화를 최소화하기 위해 능동 바이어스 회로를 구성하였다. 전류 붕괴(current collapse)와 열 폭주(thermal runaway)를 방지하기 위하여 ballast 저항을 삽입하여 전력 증폭기의 성능 및 신뢰성을 최적화하였다. 제작된 선형 전력 증폭기는 중심 주파수 900 MHz의 one-tone 신호를 사용하였을 때, 17.6 dB의 전력 이득과 30 dBm의 OP1dB를 가지며, 이때 44.9 %의 PAE를 갖는다. 또한, two-tone 신호를 인가하였을 때, 20 dBm의 평균 출력 전력에서 47.3 dBm의 매우 높은 OIP3를 갖는다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.400-403
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• 2002

The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments were primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -10.8 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 ${\mu}$m aluminum filter were less than 30 ${\mu}$s, and we detected the aluminum characteristic x-ray intensity using a 6.8 ${\mu}$m aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted and diffused greatly after passing through two slits.

• 생명과학회지
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• 제19권10호
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• pp.1389-1395
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• 2009

천연물 신약으로 응용 가능성이 있는 목초액을 산화응집반응과 활성탄 등을 첨가하여 증류하는 방법으로 제조하였으며, 장기보존과 가속 저장 조건에서 목초액의 이화학적 변화(pH, 비중, 굴절률 및 용해 타르), 유해물질(카르보닐기, 벤조피렌 및 잔류용매) 그리고 유기산(개미산, 초산 및 프로피온산)의 변화를 검토하여 안정성을 평가하였다. 또한, 발모 모델로서 C57BL/6 마우스를 이용하여 모발 성장 효과를 살펴보았다. 보관 기간 중에 어떤 화학 결합이 일어나거나 또는 분해반응이 반복적으로 일어나지 않았다. 또한, 유해성분이나 주성분이 일정하게 유지되었고 특히 발암물질인 벤조피렌은 검출되지 않았다. 정제된 목초액 또는 미녹시딜을 2주 동안 등에 도포한 후, 어떤 임상 증상 없이 음성 대조군인 생리식염수보다 모발 성장을 촉진하였다. 따라서 화장품이나 천연물 신약으로 응용가능성이 높은 목초액을 함유한 제품 개발 시 일정한 양으로 유지되는 주성분을 함유하면서 페놀과 같은 유해물질을 줄일 수 있는 방법이 가능할 뿐만 아니라 모발 성장 촉진 효과가 있어 탈모환자에도 유용하게 사용될 것으로 기대되어진다.

• 암석학회지
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• 제4권2호
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• pp.144-152
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• 1995

단양에서 동남동으로 약 6km 떨어진 천동리 지역에는 조선누층군의 최하부층인 장신규암과 영남육괴의 선캠브리아기로 추측되어온 엽리상 화강암(소위 화강암질 편마암)이 직접 접하고 있다. 이들의 관계는 전통적으로 장산규암이 엽리상 화강암을부정합으로 피복한 것으로 생각되었다. 그러나, 장판 규암의 하부에 관찰되는 소위 기저역암은 주로 규암으로 엽리상 화강암의 역을 전혀 가지고 있지 않아 두 암석 단위의 경계를 부정합으로 보기는 힘들다. 반면, 이지연의 최근 구조지질학적 연구는 이 경계가 여성전단운동에 의한 단층접촉임을 보이고 있다. 그러나, 이 전단대의 전단감각과 운동시기에 대해서는 아직 분명하지 않다. 우리는 옥동 단층의 일부인 천동리 지역 반취성전단대(semi-brittle shear zone)에서 나타나는 엽리상 패쇄암(foliated cataclasite)과 천매압쇄암(phyllonite)의 중구조 및 미구조 관찰하였는데, 이들은 북서측의 장산규암층이 남동측의 엽리상 화강암에 대해서 북동측으로 이동한 전단감각(top-to-the-northeast shearing)을 나타낸다(즉, 우수 주향이동), 전단운동의 시기를 제한하는 한 방법으로, 전통적으로 선캠브리아기루 추정되나 그 관입시기가 확인되지 않는 엽리상 화강암에 대하여 Pb-Pb 연대측정을 시도하였다. 즉, 구조운동을 받은 화강암체의 관입시기는 구조운동 시기으 l상한을 지시할 수 있기 때문이다. 엽리상 화강암의 전암 및 장석과 포획암의 전암에 대한 Pb 동위원소 자료는 $^{207}Pb/^{204}Pb-^{206}Pb/^{204}Pb$ 그림에서 $2.16{\pm}0.15$ Ga ($2{\sigma}$;MSWD=4.4)의 연대를 정의한다. 이 연대는 엽리상 화강암의 관입시기로 해석되는데, 보고된 영남육괴의 화성활동 시기와 잘 일치한다. 이 원생대 초기의 관입시기는 전통적인 생각기 옭음을 확인해 주며 전단운동의 시기를 알기위해서는다른 방법이 시도되어야 함을 지시한다.

• 한국전자파학회논문지
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• 제29권10호
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• pp.758-765
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• 2018

본 논문은 65-nm Complemetary Metal-Oxide-Semiconductor(CMOS) 공정으로 설계한 송신 1채널, 수신 2채널을 내장한 24 GHz 송수신 칩과 이 칩을 이용하여 제작한 24 GHz Frequency Modulated Continuous Wave(FMCW) 레이다 모듈을 제시한다. CMOS 송수신 칩은 14체배기, 저잡음 증폭기, 하향 변환 믹서, 전력 증폭기를 포함하고 있다. 송신 출력은 23.8~24.36 GHz 대역에서 10 dBm 이상이며, 위상 잡음은 1 MHz 오프셋에서 -97.3 dBc/Hz이다. 수신기는 25.2 dB의 변환 이득과 -31.7 dBm의 $P_{1dB}$를 갖는다. 송수신 칩은 모두 합해 295 mW를 소모하고 $1.63{\times}1.6mm^2$의 면적을 차지한다. 레이다 시스템은 FR4 기판과 저손실 듀로이드 기판을 적층하여, 저손실 기판위에 칩과 안테나 및 고주파 전송선을 배치하고, 바이어스 회로와 이득 블록, FMCW 신호 발생 블록은 FR4 기판에 집적하여 하나의 레이다 모듈을 구성하였다. 안테나는 패치 형태로 송신 안테나는 $4{\times}4$ 패치 안테나로 14.76 dBi의 안테나 이득을 수신 안테나는 $4{\times}2$ 패치 안테나로 11.77 dBi의 안테나 이득을 구현하였다. 코너 리플렉터를 사용하여 거리 및 방위각 탐지 실험을 수행하였고, 정상 동작을 확인하였다.

• 한국식품조리과학회지
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• 제25권1호
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• pp.74-83
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• 2009

We investigated the food service management practices in child care centers operated by various types of foundations in the Chonbuk area of Korea. Self-administered questionnaires were collected from 125 child care center directors. The statistical analysis was completed using an SPSS v11.5 program. Approximately 82.4% of the directors were women with an the average age of 45 years old. The average number of children in each public and private child care center was 84.7 and 88.8, respectively (P<.001), and the difference in time of operation was significant(P<.001). Only 20.8% of the centers employed a dietitian, whereas 92.0% of the centers employed a cook, thus, food service was not managed by professionals in most centers. In approximately 99.2% of the centers, meals were prepared in a conventional manner. The difference in daily meal frequency was significant(P<.05), with approximately 85.6% of the centers serving snacks twice a day primarily to supplement the intake of nutrients(4.44 point) and to add fun to the daily lives of the children(4.12 point). Approximately 40.7% of the directors of public centers and 57.6% of the directors of private centers responded that the most difficult aspect of food service management was financial management. Overall, 56.8% of the directors responded that the details of financial management had the greatest effect on their ability to improve the quality of food service. In most centers, the center director was also the purchasing manager and half of them purchased food every day. Approximately 97% of the directors responded that they do not include instant foods in their menu plans but they would use them if the children wanted to eat them. These results indicate that the food service management in child care centers in the Chonbuk area is relatively inadequate. We strongly recommend that they hire dietitians for food service administration and focus on strengthening sanitation management.

• The Korean Journal of Pain
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• 제1권1호
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• pp.20-27
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• 1988

Continuous cervical epidural anesthesia with two different concentrations of bupivacaine had been performed in 43 cases for surgery of upper extremity and cervical spine. After the initial dose of 0.33% bupivacaine 15ml to Group I(n=22) and 0.5% bupivacaine 15ml to Group II(n=21) was injected respectively, we observed the circulatory and pulmonary functions to be changed, and evaluated the duration of those analgesic action. The number of spinal segment to be affected and the complications were checked. Statistical significance of changes after the initial dose in both groups was determined by student's t-test. All values are impresed as mean$\pm$1S.D.. The results were as follows: 1) Circulatory functions; Systolic B.P. and Pulse rate were decreased by 10~15torr and 5~6 beats per minute respectively between 10~30 minutes following the initial dose, which were statistically significant in both groups. 2) Pulmonary functions; The diminution of minute volume showed to 20% and a rise of $PaCO_2$ level to 5~6 torr respectively between 30~60 minutes following the initial dose, which were statistically significant in both groups. There were no significant changes in self respiration and respiratory rate in both groups. 3) The duration of analgesic action was $72.3{\pm}25.7$(min) in Group I and $83.5{\pm}28.5$(min) in Group II which was not statistically significant between two groups, and the number of affected spinal segment at ore hour following the Anesthusia was $8.7{\pm}2.0$ in Group I and $10.5{\pm}2.4$ in Group II which was statistically significant between two groups. 4) Complications; a. Hypotension(below 80torr in systolic pressure) was appeared in 5% of all patients. b. Bradycardia(below 60 beats per minutes) was appeared in 25% of all patients. c. Inadvertent dural puncture was developed in only one patient, In conclusion, the 0.33% bupivacaine as well as 0.5% bupivacaine were enough for those analgesic effect in the above mentioned surgery even though the duration of analgesic action was about 10 minutes shorter in Group I than that of Group II. The cardiopulmonary function was clinically rather stable in Group I than that of Group II. Therefore we thought 0.33% bupivacaine was satisfactory for the clinical practicality in the cervical epidural anesthesia.

• 대기
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• 제26권2호
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• pp.227-241
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• 2016

This study investigated the cause of the heavy snowfall that occurred in the East Coast of Korea from 6 February to 14 February 2014. The synoptic conditions were analyzed using blocking index, equivalent potential temperature, potential vorticity, maritime temperature difference, temperature advection, and ground convergence. During the case period, a large blocking pattern developed over the Western Pacific causing the flow to be stagnant, and there was a North-South oriented High-to-Low pressure system over the Korean Peninsula because of this arrangement. The case period was divided into three parts based on the synoptic forcing that was responsible for the heavy snowfall; detailed analyses were conducted for the first and last period. In the first period, a heavy snowfall occurred over the entire Korean Peninsula due to strong updrafts from baroclinic instability and a low pressure caused by potential vorticity located at the mid-troposphere. In the lower atmosphere, a North-South oriented High-to-Low pressure system over the Eastern Korea intensified the easterly airflow and created a convergence zone near the ground which strengthened the upslope effect of the Taebaek Mountain range with a cumulative fresh snowfall amount of 41 cm in the East Coast region. In the last period, the cold air nestled in the Maritime Province of Siberia and Manchuria strengthened much more than that in the first half and extended to the East Sea. The temperature difference between the 850 hPa air and the SST was large and convective clouds developed over the sea. The highest cumulative fresh snow amount of 39.7 cm was recorded in the coastal area during this period. During the entire period, vertically oriented equivalent potential temperature showed neutral stability layer that helped the cloud formation and development in the East Coast. The 2014 heavy snowfall case over the East Coast provinces of Korea were due to: 1) stagnation of the system by blocking pattern, 2) the dynamic effect of mid-level potential vorticity of 1.6 PVU, 3) the easterly air flow from North-South oriented High-to-Low pressure system, 4) the existence of vertically oriented neutral stable layer, and 5) the expansion of strong cold air into the East Sea which created a large temperature difference between the air and the ocean.

• 한국식품영양과학회지
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• 제37권6호
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• pp.696-700
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• 2008

Gallic acid와 linoleic acid의 합성물인 octadeca-9,12-dienyl-3,4,5-trihydroxybenzoate(GA-LA)의 화장품산업에서의 이용 가능성을 알아보기 위하여 유전독성학적 안전성을 확인하고 크림 베이스 유화물을 사용하여 전자공여능, FRAP 및 tyrosinase 활성 억제능력과 같은 GA-LA의 생리 기능성 실험을 실시하였다. 그 결과 유전독성학적 안전성이 확인되었고, 산화에 의한 피부의 노화를 억제하기 위한 항산화 능력과 미백과 관련된 tyrosinase 활성 억제 능력이 있음이 확인되었다. 따라서 GA-LA는 식품산업뿐만 아니라 화장품산업에서 유용한 기능성 물질로 쓰일 수 있을 것이라고 생각되어진다.