Presurgical Naso-Alveolar Molding Appliance for Unilateral Cleft Lip and Palate

Baek, Seung-Hak,Yang, Won-Sik,Kim, Sukwha 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.6

본 연구의 목적은 1)편측성 순구개열 신생아 환자에 대한 술전 비치조 정형장치(PNAM)치료를 소개하고 2) 이 장치의 치조골 정형 효과를 평가하는 것이다. 서울대학교 병원 교정과에 내원하여 PNAM장치를 사용하여 치료받은 4명의 편측성 순구개열 호나자(남자 3명, 여자 1명, 평균 초진연령: 23.2일)을 대상으로 하였으며, 치조골에서 대분절과 소분절 파열부간의 평균거리는 8.27mm였고 치조골 정형치료의 평균기간은 9.7주였다. 초진시(Ti)와 성공적인 치조골 정형술이 이루어진 시기(T2)에 이들 환자의 인상을 채득하여 모형을 제작한 후, 사진촬영과 digital caliper를 사용하여 7개의 길이 항목과 5개의 각도항목을 계측하였다. SPSS win. ver 7.5프로그램을 사용하여 통계처리 하였고, 평균치의 차이를 비교하기 위하여 paired t-test를 사용하였다. 1. 신생아 치조골 후방부는 치조골 정형술을 시행하는 동안 안정된 구조물이었다. 2. 치조골 정형술에 의하여 대분절의 전방 성장이 억제되었다. 3. 치조골 정형술에 의한 파열부의 패쇄는 주로 대분절 전방부의 내측과 후방 굴곡 및 소분절 전체의 외측 굴곡에 의한 것이었다. The goals of this study were to present presurgical naso-alveolar molding(PNAM) appliance in unilaterla cleft lip and palate treatment and to evaluate the effects of PNAM appliance on alveolar molding. Samples were consisted of 4 unilateral cleft lip and palate infants(3 males and 1 female, mean age=23.2 days after birth) who were treated with PNAM appliances in Department of Orthodontics, Seoul National University Dental Hospital. Average alveolar cleft gap between the greater and lesser segment was 8.27 mm and average duration of alveolar molding treatment was 9.7 weeks. These patients' models were obtained at initial visit(T1) and after successful alveolar molding(T2). Seven linear and five angular variables were measured by using photometry and digital caliper. All statistical analyses were performed by SPSS win ver. 7.5 program. Paired t-test was used to compare the mean values. 1. The posterior part of alveolar segments are the stable structures during alveolar molding treatment period in infants. 2. Forward growth of th greater segment may be hindered by the action of alveolar molding. 3. The closure of cleft gap during alveolar molding were usually due to inward and backward bending of the anterior part of the greater segment and outward bending of the whole lesser segment.

Cross-country Comparison of Effects of ‘Confidence in Science’ and ‘Instructional Clarity in Science Lessons’ on ‘Science Achievement’: Focusing on the Mediation Effect of ‘Interest in Learning Science’*

Baek,Sun-Geun,Cho,Sijung,Yang,Hye-Won,Kim,Seojin 서울대학교 교육종합연구원 2021 The SNU Journal of Education Research Vol.30 No.4

The effects of ‘confidence in science’ and ‘instructional clarity in science lessons’ on ‘science achievement’ mediated by ‘interest in learning science’ were investigated comparatively across South Korea, Japan, the USA, and England. From the data of TIMSS 2019, 3,861 cases from South Korea, 4,446 cases from Japan, 8,698 cases from the USA, and 3,365 cases from England were used to test a hypothesized structural equation model. As a result, the model fitted the data of each country satisfactorily, and measurement was found to be equivalent across the four countries. Moreover, the effect of confidence on achievement was statistically significant in all countries whereas the effect of instructional clarity on achievement and the effect of interest on achievement were only significant in South Korea and the USA. Furthermore, the mediation effect of interest was only significant in South Korea and the USA. Such results provide new perspectives in the role of confidence, instructional clarity, and interest on students’ science achievement and implications for customized educational programs and policies for each country.

Physiochemical Response of Native Grasses under Drought and Salinity Stresses as Sustainable Garden Plant Materials

Saeng Geul Baek,Jung Won Shin,Jeong Min Seo,Jeong Min Kim8) 한국화훼학회 2024 한국화훼학회 정기총회 및 학술발표회 자료집 Vol.32 No.1

자동착유시스템 설치농가의 설치 후 만족도에 관한 실태조사

기광석,김종형,정영훈,김윤호,박성재,김상범,이왕식,이현준,조원모,백광수,김현섭,권응기,김완영,여준모,Ki, Kwang-Seok,Kim, Jong-Hyeong,Jeong, Young-Hun,Kim, Yun-Ho,Park, Sung-Jai,Kim, Sang-Bum,Lee, Wang-Shik,Lee, Hyun-June,Cho, Won-Mo,Baek, Kwang- 한국축산환경학회 2011 축산시설환경학회지 Vol.17 No.1

본 시험은 국내에 도입되기 시작한 AMS에 대하여 설치 동기, 설치 후 우유생산량과우유품질, AMS 설치계기 및 설치 후 만족도, AMS 운영상 애로점 및 건의사항 등을 조사 분석하였다. 설치 계기가 무엇인가에 대한 응답비율은 노동력 부족 44%, 체험목장으로 전환 25%, 소들의 고능력화에 대응 19% 순이었으며 기타 6%였다. AMS 설치농가의 사육경력은 평균 24.9년, 평균 연령은 53.2세로 나타났으며 가족노동력만으로 경영하는 목장이 조사농가의 38%, 고용+자가노동력 형태의 목장이 63%로 나타났다. 목장의 산유능력은 두당 평균 유량은 1일 $30.9{\ell}$, 평균 유지율 3.9%, 세균수는 9.1천개/$m{\ell}$ 수준이었다. 후계자 육성에 대한 질문에 매우 그렇다라고 응답한 비율은 68%였으며, 보통 18%, 아니다와 매우 아니다라고 응답한 비율은 18%로 나타났다. 시스템 운영현황 및 애로사항을 파악하기 위하여 AMS의 프로그램 주운영자에 대한 질문에 본인 44%, 부인 6%, 자녀 또는 후계자사람이 44%, 기타 6%나 되었다. AMS 운영상 가장 어려운 점에 대한 조사결과, 기기 작동 및 복잡한 프로그램 운영이 각각 31%로 가장 많았다. 그 외 기계 에러 및 고장에 대한 애로사항이 25%이였다. 도태원인에 대하여 유방염 28%, 번식장애 20%, 발굽질환 19%, AMS에 부적합한 유두 배열 12%, 분만 후 대사성질병 7%, 노산 등 기타 14%였다. 시스템 설치 후 유지보수 계약 체결유무 및 비용에 대하여 유지보수 계약 56%, 유지 보수 계약 미체결 44%이었다. 유지보수 계약 평균 계약비용은 연간 658만원 정도였다. 시스템 설치 후 항목별 만족도에 대하여 5점 만점에 3.9점이었으며, 노동력 절감 3.7점, 업체의 A/S 3.6점, 산유량 증가 3.2점, 원유의 체세포 수 저감 2.8점이었다. 시스템 설치 시 고려사항 및 건의사항에 대하여 고가의 장비를 효율적으로 사용하기 위하여 젖소의 유방과 유두 배열이 적합하도록 젖소를 선발하는 것, 시스템을 운용할 수 있는 능력, 적합한 환경, 재정적 능력과 부지 확보, 지속적인 관찰 등이 권장되어야 할 것으로 나타났으며, 설치 업체에 대해서는 컨설팅이 체계화될 필요가 가장 높게 나타났으며 이어서 보다 저렴한 설치와 서비스의 체계화를 요구하는 결과를 보였다. The present survey was conducted to provide basic information on automatic milking system (AMS) in relation to purchase motive, milk yield and quality, customer satisfaction, difficulties of operation and customer suggestions, etc. Purchase motives of AMS were insufficient labor (44%), planning of dairy experience farm (25%), better performance of high yield cows (19%) and others (6%), respectively. Average cow performance after using AMS was 30.9l/d for milk yield, 3.9% for milk fat, 9,100/ml for bacterial counts. Sixty-eight percentage of respondents were very positive in response to AMS use for their successors but 18% were negative. The AMS operators were owner (44%), successor (44%), wife (6%) and company worker (6%), respectively. The most difficulty (31%) in using AMS was operating the system and complicated program manual. The rate of response to system error and breakdown was 25%. The reasons for culling cow after using AMS were mastitis (28%), reproduction failure (19%), incorrect teat placement (12%), metabolic disease (7%) and others (14%), respectively. Fifty-six percentages of the respondents made AMS maintenance contract and 44% did not. Average annual cost of the maintenance contract was 6,580,000 won. Average score for AMS satisfaction measurement (1 to 5 range) was 3.2 with decrease of labor cost 3.7, company A/S 3.6, increase of milk yield 3.2 and decrease of somatic cell count 2.8, respectively. Suggestions for the higher efficiency in using AMS were selecting cows with correct udder shape and teat placement, proper environment, capital and land, and attitude for continuous observation. Systematic consulting was highly required for AMS companies followed by low cost for AMS setup and systematization of A/S.

A prospective association between dietary mushroom intake and the risk of type 2 diabetes: the Korean Genome and Epidemiology Study–Cardiovascular Disease Association Study

Yu-Mi Kim(Yu-Mi Kim),Hye Won Woo(Hye Won Woo),Min-Ho Shin(Min-Ho Shin),Sang Baek Koh(Sang Baek Koh),Hyeon Chang Kim(Hyeon Chang Kim),Mi Kyung Kim(Mi Kyung Kim) 한국역학회 2024 Epidemiology and Health Vol.46 No.-

The effect of oxygen functional groups on the electrical transport behavior of a single piece multi-layered graphene oxide

Baek, Seung Jae,Hong, Won G.,Park, Min,Kaiser, Alan B.,Kim, Hae Jin,Kim, Byung Hoon,Park, Yung Woo Elsevier 2014 Synthetic metals Vol.191 No.-

To investigate the electronic transport mechanisms in multi-layered graphene oxide (MGO), the temperature-dependent electrical conductivity (sigma(T)) has been measured as a function of the annealing temperature (T-a). An individual MGO flake was gradually reduced by thermal annealing at T-a from 88 to 300 degrees C, with the reduction process confirmed at each stage by X-ray photoelectron spectroscopy. As T-a increases, the sigma(T) of the MGO also increases. We found that the sigma(T) is well interpreted by variable-range hopping in disordered regions in series through activated conduction across small barriers. We associate the localized states for hopping with the oxygen functional groups in GO, as well as the small activation barriers with the domain boundaries between the clustered oxygen functional groups and the graphitic region. Both the hopping and activation barrier resistances decrease systematically as the T-a increases. (C) 2014 Elsevier B.V. All rights reserved.

Enhanced species-specific chemical control of harmful and non-harmful algal bloom species by the thiazolidinedione derivative TD49

Baek, Seung Ho,Son, Moonho,Jung, Seung Won,Na, Dong Hee,Cho, Hoon,Yamaguchi, Mineo,Kim, Si Wouk,Kim, Young Ok Springer-Verlag 2014 Journal of applied phycology Vol.26 No.1

High-Efficiency Isolated Bidirectional AC–DC Converter for a DC Distribution System

Kim, Ho-Sung,Ryu, Myung-Hyo,Baek, Ju-Won,Jung, Jee-Hoon IEEE 2013 IEEE transactions on power electronics Vol.28 No.4

<P>A high-efficiency isolated bidirectional ac–dc converter is proposed for a 380-V dc power distribution system to control bidirectional power flows and to improve its power conversion efficiency. To reduce the switches’ losses of the proposed nonisolated full-bridge ac–dc rectifier using an unipolar switching method, switching devices employ insulated-gate bipolar transistors, MOSFETs, and silicon carbide diodes. Using the analysis of the rectifier’s operating modes, each switching device can be selected by considering switch stresses. A simple and intuitive frequency detection method for a single-phase synchronous reference frame-phase-locked loop (SRF-PLL) is also proposed using a filter compensator, a fast period detector, and a finite impulse response filter to improve the robustness and accuracy of PLL performance under fundamental frequency variations. In addition, design and control methodology of the bidirectional full-bridge CLLC resonant converter is suggested for the galvanic isolation of the dc distribution system. A dead-band control algorithm for the bidirectional dc–dc converter is developed to smoothly change power conversion directions only using output voltage information. Experimental results will verify the performance of the proposed methods using a 5-kW prototype converter.</P>

Ellagic acid plays a protective role against UV-B-induced oxidative stress by up-regulating antioxidant components in human dermal fibroblasts

Baek, Beomyeol,Lee, Su Hee,Kim, Kyunghoon,Lim, Hye-Won,Lim, Chang-Jin The Korean Society of Pharmacology 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.3

Ellagic acid (EA), an antioxidant polyphenolic constituent of plant origin, has been reported to possess diverse pharmacological properties, including anti-inflammatory, anti-tumor and immunomodulatory activities. This work aimed to clarify the skin anti-photoaging properties of EA in human dermal fibroblasts. The skin anti-photoaging activity was evaluated by analyzing the reactive oxygen species (ROS), matrix metalloproteinase-2 (MMP-2), total glutathione (GSH) and superoxide dismutase (SOD) activity levels as well as cell viability in dermal fibroblasts under UV-B irradiation. When fibroblasts were exposed to EA prior to UV-B irradiation, EA suppressed UV-B-induced ROS and proMMP-2 elevation. However, EA restored total GSH and SOD activity levels diminished in fibroblasts under UV-B irradiation. EA had an up-regulating activity on the UV-B-reduced Nrf2 levels in fibroblasts. EA, at the concentrations used, was unable to interfere with cell viabilities in both non-irradiated and irradiated fibroblasts. In human dermal fibroblasts, EA plays a defensive role against UV-B-induced oxidative stress possibly through an Nrf2-dependent pathway, indicating that this compound has potential skin antiphotoaging properties.

Hybrid Nanocomposite of CdSe Quantum Dots and a P3HT-<i>b</i>-PDMAEMA Block Copolymer for Photovoltaic Applications

Kim, Sung Won,Kim, Dongh Wan,Kim, Hyun Ji,Lee, Yun Jae,Wang, Seung Sangh,Baek, Kyung Youl Trans Tech Publications, Ltd. 2012 Materials science forum Vol.700 No.-

<P>We synthesized a new hybrid nanocomposite consisting of CdSe quantum dot (QD) and regioregular poly (3-hexylthiophene)-<I>b</I>-poly (<I>N,N</I>-dimethylamino-2-ethylmethacrylate) rod-coil block copolymer to investigate the effects of nanoscale morphology to the photovoltaic properties in inorganic-organic hybrid solar cell. Well-defined conducting rod-coil block copolymers, P3HT-<I>b</I>-PDMAEMA, were synthesized by combination of Grignard metathesis polymerization (GRIM) and atom transfer radical polymerization (ATRP) methods. These rod-coil block copolymers were then mixed with oleic acid capped CdSe QDs through ligand exchange and characterized their nanoscale morphology and optoelectronic properties. These results can be explained by the effects of the bicontinuous electron-donor/electron-acceptor networks in active layer based on rod-coil P3HT-<I>b</I>-PDMAEMA block copolymers blended with CdSe QDs.</P>