최신 모뎀 칩 개발 동향 및 향후 전망

이재학 대한전자공학회 2014 전자공학회지 Vol.41 No.12

평면 변압기를 이용한 자동차용 고압방전등 안정기 시스템

이재학 대한전자공학회 2006 電子工學會論文誌 IE (Industry electronics) Vol.43 No.3

This paper presents the control system of high-efficiency automotive 35W metal-halide lamp ballast using the new control method and planar transformer. In this paper, the electronic ballast is designed so that digital control method by microcontroller can be applied to the electronic ballast for the lamp requirement and peripheral environment in order that metal-halide lamp, which has the complicated transient features, is to be applied to the automobile even if it has superior features in brightness, color rendering, light efficiency, and lifespan compared to the conventional halogen lamp. Also, the efficiency increase of the ballast is devised by being varied the switching frequency of Flyback Converter following the battery input voltage of the automobile. Being designed for high-frequency switching transformer of converter in planar form, reduction of loss, weight , overall size are realized and efficient power control in the automobile that had the limited energy and the limited space of battery is devised. The results of the proposed system is verified through various experiment results. 본 논문에서는 새로운 제어방식과 평면 변압기(planar transformer)를 이용한 자동차용 35W급 메탈헬라이드 램프용 고효율 전자식 안정기의 제어시스템을 제안하였다. 본 논문에서는 밝기, 연색성, 광효율, 수명 등에서 기존의 할로겐 램프에 비해 우수한 특성을 가지고 있지만 복잡한 과도특성을 가지고 있는 메탈헬라이드 램프를 자동차에 적용하기 위해 마이크로컨트롤러에 의한 디지털 제어방식을 전자식 안정기에 적용하여 램프 요구조건 및 주변 환경에 최적으로 적용할 수 있도록 전자식 안정기를 설계하였다. 또한, 자동차의 밧데리 입력전압에 따라 안정기 컨버터(Flyback Converter)의 스위칭 주파수를 가변하여 안정기의 효율증대를 도모하였고, 컨버터의 고주파 스위칭 변압기를 평면 형태로 설계하여, 기존의 고주파 변압기에 비해 손실, 무게 등의 절감과 전체적인 크기를 축소하여, 밧데리라는 한정된 에너지와 한정된 공간을 갖는 자동차에서 효율적인 전력제어를 실현하였다. 개발된 안정기에 대한 동작특성을 실험을 통해 확인하였다.

정상 성인 상·하지에 냉적용후 공감반응에 관한 연구

이재학,함용운,윤범철 高麗大學校 倂設 保健大學 保健科學硏究所 1995 保健科學論集 Vol.21 No.1

The purpose of this study is to confirm "Cold Consensual Reaction". We applied cold respectively on right hand and right foot in normal 20 subjects and then authors investigated the changes of shell temperature, core temperature, blood pressure of other extremities. The results are as follows : 1. Applying cold to the upper extremity, the contralateral upper extremity and both lower extremities were statistically significant respectively after 5 minutes and 7 minutes of this experiments. 2. Applying cold to the lower extremity, the contralateral lower extremity and both uppe extremities were statistically significant respectively after 5minutes and 3∼4 minutes of this experiments. 3. All core temperature after cold application were statistically nonsignificant. 4. As shell temperature were the lowest records, after cold application were high records but there were statistically nonsignificant. 5. Applying cold to the upper extremity the decreased temperature of contralateral upper extremity was lower than both lower extremities. 6. Applying cold to the lower extremity the decreased temperature of the contralateral lower extremity was same that of both upper extremities and it was much less lower than that of the contralateral upper extremity.

윈드서핑 운동이 비만여고생의 체조성과 혈청지질 및 지단백에 미치는 영향

이재학 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

The purpose of this study was our research is to find how to influence the change of body composition, Serum Lipids, and Liporotein in Obese high school girls as they exercise wind surfing, which we enjoy with interest, and is a kind of aerobic exercise during 10 weeks. We chose ten in Obese high school girls whose % body fat is over than 35% at K high school in Ulsan city. And we let them exercise wind surfing for one and a half or two hours three times a week during 10 weeks. The findings of this study were as follow; 1. In the changes of body composition factors, body weight, body fat, % body fat and body mass index were significantly decreased, but lean body mass was significantly increased after 10-week wind surfing exercise 2. In the changes of serum Lipids, and Lipoprotein factors, total cholesterol, triglyeride, low-density Liporotein cholesterol and apolipoprotein B were significantly decreased, but high-density Liporotein cholesterol and apolipoprotein A-Ⅰ was significantly increased after 10-week wind surfing exercise. Wind surfing exercise brought a positive change on body composition, Serum Lipids, and apolipoprotein in obesee high school girls.

전기사용 합리화를 위한 계약전력 초과억제장치의 사용

이재학 대한전기협회 1979 대한전기협회지 Vol.- No.28

코인두로 전이된 대장암

이재학,전은정,최현호,홍석인,김진일,김재광,이연수 대한내과학회 2011 대한내과학회지 Vol.80 No.-

Metastatic adenocarcinoma from the gastrointestinal tract to the nasopharynx is rare. The histological morphology of this lesion is indistinguishable from the colonic variant of primary head and neck adenocarcinoma or intestinal-type adenocarcinoma (ITAC) of the nasal cavity. This is a report of metastatic adenocarcinoma of colorectal origin to the nasopharynx in a 58-year-old man who was previously treated for adenocarcinoma of the sigmoid colon. A histopathological study of the specimen from the nasopharynx demonstrated a tumor that was identical to the patient’s previous primary tumor from the colon. There was no tumor mass in the nasal cavity or paranasal sinuses. The nasopharyngeal tissue expressed cytokeratin 20 and CDX-2, but not cytokeratin 7. The patient received palliative radiation after the diagnosis. Distinguishing metastatic adenocarcinoma from the gastrointestinal tract from ITAC can be difficult. The clinical manifestation is important in differentiating these conditions. It is important to recognize these as metastatic lesions because treatment is primarily palliative. (Korean J Med 2011;80:S96-S100) 대장에서 전이된 선암은 비강 및 부비동에서 발생하는 장형 선암과 조직학적으로 매우 비슷하여 구분이 어렵다. 대장암으로 전신화학요법을 시행하고 있는 환자에서 코인두에 종양이 발생하여 영상검사와 조직검사, 면역조직화학검사를 시행하였다. 시행한 영상학적 검사에서 장형 선암이 잘 발생하는 비강과 부비동에는 종양이 발견되지 않았다. 조직검사에서는 원발 병소와 병리조직학적으로 비슷한 모습을 보였으며 면역조직화학검사에서 CK20와 CDX-2에서 양성을 나타냈고, CK7은 음성을 나타내어 대장암의 코인두 전이로 진단하였다. 대장에서 전이된 선암과 장형 선암의 감별은 조직검사만으로는 구분하기가 어렵다. 임상적인 감별이 필요하며 적극적인 영상학적 검사와 면역조직학적검사가 시행되어야 한다. 저자들은 58세 남자 환자에서 대장암의 치료과정에서 발생한 코인두 전이를 경험하고 코인두에서 선암이 발생하였을 경우 대장암의 전이를 고려해야 한다고 생각되어 문헌고찰과 함께 보고한다.

지수적 방법에 의한 한국물류기업의 생산성분석

이재학 한국유통학회 1998 한국유통학회 학술대회 발표논문집 Vol.- No.-

Amaranth의 Squalene 동정과 잔사 추출물의 항암 작용 검색

이재학,문형인,이정일,강철환,이승택 韓國作物學會 1996 한국작물학회지 Vol.41 No.4

국내에서 종실용 amaranth의 이용 가능성을 조사하기 위한 목적으로 종실에서 squalene을 분리, 동정하였고, squalene 추출후 부산물의 활용방안으로 그 부산물의 항암활성검색을 한 결과를 요약하면 다음과 같다. 1. Amaranth 종실에서 추출, 분리한 squalene 함량은 0.43%이고, GC /Mass spectrum으로 확인한 결과 99%의 순도를 나타내었으며, 분자구조식은 잠정적으로 동물성 squalene과 동일한 것으로 나타났다. 2. MTT 방법을 이용한 인간의 위암, 대장암 세포주에 대한 항암활성효과를 검색한 결과 부산물의 조추출물은 230ug/m1보다 낮은 농도에서 유의한 항암효과를 보였다. In this study isolation and identification of squalene from amaranth and antineoplastic activity of its residue extract except squalene were determined to examine the utilization of grain amaranth in Korea. The content of squalene in amaranth grain was about 0.43%. The isolated squalene showed 99% pureness containing the identical molecular weight and structure provisionally in comparison with that of animal squalene from Sigma Co. by means of GC /Mass spectrum. Antineoplastic activity against human gastric and colon carcinoma cell line was measured in extract (except squalene) from Amaranth using MTT method. Extract from remaining plant good showed significant cytotoxic effect at the concentration of less than 230~mu~textrmg /ml.

광복이후 한국 무도에 보이는 <신체문화>에 관한 연구

이재학,김창우,이동헌 한국스포츠리서치 2007 한국 스포츠 리서치 Vol.18 No.1

한국에서의 아시아 인접국 국가이미지 분석: 중국과 일본을 중심으로.

이재학 고려대학교 언어정보연구소 2011 언어정보 Vol.0 No.12

This paper investigates the image of Asian Couries in Korea including Japan, China, Singapore, India, Indonesia and Malaysia. To do this, this paper analyzes the Anholt Nation Brands Index which measures people's perception of a country across six areas of national competence. These six areas are Tourism, Exports/Products, Governance, Investment/Immigration, Culture/Heritage and People. This paper also investigates the Korean news media since "quantitative content analysis is the systematic assignment of communication content to categories according to rules, and the analysis of relationships involving those categories using statistical methods" (Riffe 2005, 3). Therefore the analysis of the Korean daily news paper Chosun shows us the perceived image of these six Asian Countries in Korea. To conclude this paper shows that almost all of these Asian countries suffer from negative perceptions in Korea.