회절성 난시교정용 다초점 인공수정체의 임상결과

김지현,유성,구성현,이광자,이규원,박영정,Jee Hyun Kim,MD,Sung Yu,MD,Sung Hyun Koo,MD,Gwang Ja Lee,MD,Kyoo Won Lee,MD,Young Jeung Park,MD 대한안과학회 2014 대한안과학회지 Vol.55 No.8

Purpose: To evaluate the clinical outcomes of patients with diffractive multifocal toric intraocular lens (IOL) implantation. Methods: Thirty-four eyes of 26 patients underwent diffractive multifocal toric IOL. Uncorrected visual acuity (UCVA) at distant, intermediate and near and residual refractive astigmatism were measured on the first day, at 2 weeks, and 1, 3 and 6 months postoperatively. Optical quality obtained using the Optical Quality Analysis System II (OQAS II), high-order aberrations (HOA) and patient satisfaction questionnaire were evaluated 3 months postoperatively. Results: At the 6 month postoperative visit, the mean UCVA at distant, intermediate (63 cm, 100 cm) and near were 0.06 ± 0.07, 0.18 ± 0.11, 0.16 ± 0.12 and 0.03 ± 0.06 (log MAR), respectively. The refractive astigmatism decreased significantly from -1.66 ± 1.04 D to -0.54 ± 0.32 D at 6 months postoperatively (<em>p</em> < 0.01). The means of objective scatter index, modulation transfer function (MTF) cut-off value, Strehl ratio and pseudo-accommodation range measured by OQAS II were 1.33 ± 0.67, 37.24 ± 9.67 cdp, 0.22 ± 0.09 and 3.08 ± 0.53 D, respectively. HOA scores for 5 mm and 6 mm were 0.30 ± 0.09 and 0.49 ± 0.15, respectively; 82.3% of the patients were satisfied with the postoperative results, 79.4% of the patients reported they would recommend the procedure to others, and 14.7% of patients reported moderate or severe visual disturbance at night. Conclusions: Implantation of a diffractive multifocal toric IOL in patients with cataract and corneal astigmatism provided excellent distant, intermediate, and near visual outcomes, good optical quality and high patient satisfaction. J Korean Ophthalmol Soc 2014;55(8):1139-1149

두 개의 스펙트럼영역 빛간섭단층촬영기를 이용한 맥락막두께의 비교

김지현,유성,김진선,이규원,이정호,Jee Hyun Kim,MD,Sung Yu,MD,Jin Seon Kim,MD,Kyoo Won Lee,MD,PhD,Jung Ho Lee,MD 대한안과학회 2014 대한안과학회지 Vol.55 No.9

Purpose: To determine the difference in subfoveal choroidal thickness between two spectral-domain optical coherence tomography (SD-OCT) systems in normal eyes and eyes with retinal diseases. Methods: Thirty-three normal eyes and 49 eyes with retinal disease (13 eyes with diabetic retinopathy, 28 eyes with epiretinal membrane and eight eyes with macular hole) were enrolled in the study. Subfoveal choroidal thicknesses were measured by 3 observers using the enhanced depth imaging technique of Heidelberg Spectralis<sup><font size=`2`>Ⓡ </font>and the high-definition five-line raster scan of Cirrus HD-OCT<sup><font size=`2`>Ⓡ</font> using calipers within the program. Differences between the measured values were analyzed with a paired t-test in PASW 18.0. Results: The mean age of normal eyes was 67.31 years, while eyes with diabetic retinopathy, epiretinal membrane and macular hole were aged 56.08 years, 70.00 years and 68.50 years, respectively. The mean subfoveal choroidal thickness of normal eyes was 237.61 ± 104.60 μm for Spectralis and 239.52 ± 92.08 μm for Cirrus and showed no significant difference (<em>p</em> = 0.397). Eyes with diabetic retinopathy, epiretinal membrane, and macular hole measured 267.46 ± 74.91 μm, 236.79 ± 84.16 μm and 209.63 ± 86.71 μm for Spectralis, respectively, and 266.69 ± 73.76 μm, 226.75 ± 77.30 μm and 206.75 ± 78.69 μm for Cirrus. They also showed no statistical difference (<em>p</em> > 0.05). Conclusions: Subfoveal choroidal thickness measurements according to Heidelberg Spectralis<sup><font size=`2`>Ⓡ</font> and Cirrus HD-OCT<sup><font size=`2`>Ⓡ</font> in both normal eyes and eyes with retinal diseases showed no significant differences. J Korean Ophthalmol Soc 2014;55(9):1327-1333

의료 센서 네트워크에서 휴대폰을 이용한 사용자 인증 및 안전한 데이터 통신 방안

김지현,도인실,박정민,채기준,Kim, Jee-Hyun,Doh, In-Shil,Park, Jung-Min,Chae, Ki-Joon 한국정보처리학회 2012 정보처리학회논문지 C : 정보통신,정보보안 Vol.19 No.1

무선 센서 네트워크는 언제, 어디에서든, 때와 장소를 가리지 않고 사용자가 원하는 서비스를 제공해주는 시스템이다. 특히, 바이오 센서를 이용한 의료센서네트워크는 생명공학, 의료공학 분야에서 활발하게 활용이 되고 있다. 의료센서네트워크에서는 사용자가 시간적이나 공간적 제약을 받지 않고 집에서 건강을 모니터링 할 수 있는 환경이다. U-healthcare환경에서 긴급 상황이 발생 했을 때 빠르게 환자를 도와줄 수 있으며, 병원에서도 손쉽게 환자를 관리 할 수 있다는 장점을 갖는다. 이 환경에서는 개인의 건강과 생명에 직결된 데이터가 송수신되므로 개인의 프라이버시 보장과 데이터의 보안이 가장 중요한 요소이다. 본 논문에서는 휴대폰을 이용한 사용자 인증 방안과 데이터의 종류에 따라 긴급모드와 일반모드의 구분을 두어 안전하면서도 빠르게 데이터를 전송하는 방안을 제안하였다. Wireless sensor network provides services anytime and anywhere they are requested. Especially, medical sensor network based on biosensors is applied a lot to biotechnology and medical engineering. In medical sensor network, people can make their health checked at home free from temporal and spatial constraints. In ubiquitous healthcare environment, people can get instant help even in the emergency, and in hospital, patients can be taken care of efficiently. In this environment, health and life related data are delivered, and the privacy and security of personal data are very important. In this paper, we propose user authentication and data communication mechanism in two modes, normal and urgent situation using cellular phone. Through our proposal, data can be transferred in quick and secure manner.

만성 치주염에서 비외과적 또는 외과적 치주치료 후 유지관리기 동안 임상적 변화의 비교

김지현,정현주,Kim, Jee-Hyun,Chung, Hyun-Ju 대한치주과학회 2006 Journal of Periodontal & Implant Science Vol.36 No.1

Reports on the comparison of clinical effect between non-surgical and surgical therapy, and the change of the clinical parameters during maintenance phase have been rarely presented in Korea. This study was to observe the clinical changes during maintenance phase of 6 months in patients with chronic periodontitis treated by non-surgical or surgical therapy in Department of Periodontics, Chonnam National University Hospital. Among the systemically healthy and non-smoking patients with moderate to severe chronic periodontitis, twenty eight patients (mean age: 47.5 years) treated by non-surgical therapy (scaling and root planning) and nineteen patients (mean age: 47.3 years) treated by surgical therapy (flap surgery) were included in this study. The periodontal supportive therapy including recall check and oral hygiene reinforcement was started as maintenance phase since 1 month of healing after treatment. Probing depth, gingival recession. clinical attachment level and tooth mobility were recorded at initial, baseline and 1, 2, 3 and 6 month of maintenance phase. The clinical parameters were compared between the non-surgical and surgical therapies using Student t-test and repeated measure ANOVA by initial probing depth and surfaces. Surgical therapy resulted in greater change in clinical parameters than non-surgical therapy. During the maintenance phase of 6 months, the clinical effects after treatment had been changed in different pattern according to initial probing depth and tooth surface. During maintenance phase, probing depth increased more and gingival recession increased less after surgical therapy, compared to non-surgical therapy. The sites of initial probing depth less than 3 mm lost more clinical attachment level, and the sites of initial probing depth more than 7 mm gained clinical attachment level during maintenance phase after non-surgical therapy, compared to surgical therapy. Non-surgical therapy resulted in greater reduction of tooth mobility than surgical therapy during maintenance phase. These results indicate that the clinical effects of non-surgical or surgical therapy may be different and may change during the maintenance phase.

UWB-MB-OFDMA 시스템에서의 미세 주파수 동기화 기법

김지현(Jee Hyun Kim),정광수(Kwang-Soo Jeong),이재훈(Jae-Hoon Yi),유영환(Youn-Hwan You) 한국통신학회 2008 한국통신학회 학술대회논문집 Vol.2008 No.7

미국 학부 과정의 그래픽 디자인 교육

김지현(Jee Hyun Kim) 한국기초조형학회 2000 기초조형학연구 Vol.1 No.1

The concepts, processes, results and problems of American graphic design education was studied through the articles, books, web sites and interviews with design educators as well as the graphic design classes. In a state of flux through new technology and needs for specification and integration from new society and culture, graphic design education should be changed and reorganized the purposes, structures and contents, even though it was based on Bauhaus education. American graphic design education need to changes in graphic design category, position, program philosophies and structures, formal graphic design foundation courses, educational period, and balance of contents. This study is expected to be a great help as a prior example for the graphic design education direction in Korea.

염증성 장 질환 환자에서 면역조절제와 생물학적 제제 사용이 암 발생에 미치는 영향

김지현 ( Jee Hyun Kim ),김지원 ( Ji Won Kim ) 대한소화기학회 2017 대한소화기학회지 Vol.70 No.4

Immunosuppressive agents and biological agents are widely used for therapy in patients with inflammatory bowel disease (IBD). However, these therapies may be associated with an increased risk of malignancy. There is evidence that exposure of the therapeutic agents such as thiopurine and anti-tumor necrosis factor for IBD is associated with an increased risk of lymphoproliferative disorders, skin cancers, or uterine cervical cancers. This article reviews the malignancies associated with the use of immunosuppressive agents and biological agents in IBD. (Korean J Gastroenterol 2017;70:162-168)

Embedded RAM 테스트를 위한 BIST 회로 설계

김지현(Jee-Hyun Kim),성경호(Kyeong-Ho Seong),장종권(Jong-Kwon Chang) 대한전자공학회 1996 대한전자공학회 학술대회 Vol.1996 No.11

신용매수거래가 개별주식의 변동성, 유동성, 수익률예측력에 미치는 영향

김지현(Jee-Hyun Kim),윤선흠(Sun-Heum Yoon) 충남대학교 경영경제연구소 2017 경영경제연구 Vol.39 No.2

2014년 1월부터 12월까지 개별주식 수준에서 신용매수거래는 전체 거래량의 약 9.38%, 개인매수거래량의 약 12.11% 수준으로 나타났다. 신용매수 거래자들은 가격, 변동성, 거래횟수 등이 지나치게 높은 종목을 회피하는 경향이 있지만, 기업규모, 거래량, 거래량회전율 등에 비례하여 신용매수거래가 증가하는 경향을 보였다. 신용매수 수준이 높은 종목과 신용매수 수준이 낮은 종목 모두에서 신용매수거래가 증가하면 변동성이 감소하고, 신용매수거래가 감소하면 변동성이 증가하였다. 신용매수 수준이 낮은 종목의 경우, 신용매수거래가 증가한 경우의 스프레드가 신용매수거래가 감소한 경우의 스프레드에 비해 통계적으로 유의하게 낮게 나타났다. 또한, 신용매수 수준이 낮은 종목에서는 신용매수거래가 증가한 이후 누적초과수익률이 지속적으로 상승하였으며, 수익률 반전현상이 나타나지 않았다. 신용매수 수준이 낮은 종목에서 신용매수거래의 영향력이 크다고 할 수 있으며, 이들 종목에서 신용매수 거래자들이 단기적으로 유용한 정보를 보유하고 있지만, 신용매수거래가 개별종목 수준에서 주식시장을 교란하지 않는다고 해석할 수 있다. 추가적으로, 신용매수거래는 개인 순매수비율 등 개인투자자 거래활동과 양(+)의 상관관계를 보였으며, 최근의 주가 정보에 대해서는 더 민감하게 반응하는 추세추종거래(positive feedback trading)행태를 보였다. This study examines the impacts of margin buying on a stock market various dimensions, including volatility, liquidity, and its return predictability. Analysis of detailed firm-level data from January 2014 to December 2014 reveals that margin buying accounts for a considerable portion of the stock trading; 9.38% and 12.11% of total and individual investor trading volume, respectively. Margin-buyers have the tendency to avoid stocks showing very prominent characteristics of price, volatility and the amount of trading. In terms of volatility, we find a reverse relationship between margin buying and volatility. The stocks exhibit narrower spreads after experiencing a sharp increase in margin buying, especially when they were at a low level of margin buying. Finally, we find that stock prices with high margin buying show patterns of return predictability and no return-reversion. These findings suggest that some investors trading these stocks who are buying on margin have information for a short-term period. The empirical results also give a hint that those investors do not destabilize the stock market at the individual stock level. In addition, a strong relationship between past cumulative returns and margin buying, indicating that traders buying on margin adopt the positive feedback trading strategy, is also valuable in analyzing margin buying, but it requires further investigation.

PF계약상 대주의 인허가권 확보에 대한 검토

김지현 ( Jee-hyun Kim ),노용균 ( Yong-gyun Roh ),우지연 ( Jee-yeon Woo ),이민우 ( Min-woo Lee ) 건국대학교 법학연구소 2011 일감부동산법학 Vol.6 No.-

After obtaining permission for construction from administrative agency, a developer makes a capital financing contract with project lenders. In case a developer becomes insolvent, project lenders would make every effort to take over the project implement rights, so they can get repayment. This article examines if it is necessary to include the project implement rights transfer provision in such contracts, and shows the examples of transfer provision in contracts. It also suggests the legal approaches for taking over project implement right, such as suits for transfer rights and title transfer, and it looks through the range of acceptance and reconciliation. In addition, the research studies the possibility of transfer project implement right to project lenders inferring with Ipso facto clause, in case of the developer or the constructor`s bankruptcy. Finally, the research investigates the way for project lenders to secure the construction permission when the corporate recovery proceeds. It briefly introduces corporate recovery procedure, then shows the effect of transferring project implement right clause, obtaining the business through buying securities(debt-equity swap, enforcement of the pledge), managemental real estate trust.