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.

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

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

인사관리 공정성 인식이 공무원의 공공봉사동기에 미치는 영향 : 업무자율성과 상사피드백의 조절효과를 중심으로

김지현(Kim, Jee Hyun) 한국지방정부학회 2021 지방정부연구 Vol.25 No.2

본 연구는 공직자들을 연구대상으로 하여 인사관리에 대한 공무원의 공정성 인식이 공공봉사동기에 미치는 영향 을 탐색하고, 이러한 영향 관계에서 업무자율성과 상사피드백이 가지는 조절효과를 분석하였다. 특히 인사관리에 대한 공정성을 분배공정성, 절차공정성, 상호작용 공정성으로 나누어 분석한 결과, 인사관리에 대한 절차공정성 인 식이 공무원의 공공봉사동기에 통계적으로 유의미한 정(+)의 영향을 끼치는 것을 확인하였다. 또한 업무자율성과 상사피드백의 조절효과를 검증한 결과, 업무자율성이 높아질 때 분배공정성과 상호작용 공정성이 공공봉사동기에 미치는 영향력을 증가시켰고, 상사 피드백이 높을 때 절차공정성과 상호작용 공정성이 공공봉사동기에 미치는 영향 력을 증가시킨다는 것을 볼 수 있었다. 본 연구결과는 공공봉사동기의 선행요인으로 조직 차원에서의 공정성 가치 를 다루고, 공공봉사동기에 영향을 미치는 업무자율성과 상사피드백의 긍정적 역할을 조명하는 정책적 함의를 제공 했다는데 연구의 의의가 있다. The study analyzed the effects of pubic officials’ perception of organizational justice about Human Resource Management (HRM) on Public Service Motivation(PSM), exploring the moderating role of job autonomy and feedback. In particular, as a result of analyzing organizational justice about HRM by dividing it into three categories: distributive, procedural, and interactional justice, the findings shows that the procedural justice perceptions has a positive and statistically significant effect on PSM. The results also indicate that job autonomy and feedback significantly moderate the effect of organizational justice perception on PSM. The research result is meaningful in that it deals with justice values as a prerequisite for public service motivation, and provides policy implications that shed light on the positive role of job autonomy and feedback.

한국의 모바일 기회인가? 위기인가?

김지현(Jee-Hyun Kim) 한국정보과학회 2010 정보과학회지 Vol.28 No.6

빅데이터 통합 방법에 관한 연구

김지현(Jee-Hyun Kim),조영임(Young-Im Cho) 한국컴퓨터정보학회 2017 韓國컴퓨터情報學會論文誌 Vol.22 No.1

In this paper we propose the approach for big data integration so as to analyze, visualize and predict the future of the trend of the market, and that is to get the integration data model using the R language which is the future of the statistics and the Hadoop which is a parallel processing for the data. As four approaching methods using R and Hadoop, ff package in R, R and Streaming as Hadoop utility, and Rhipe and RHadoop as R and Hadoop interface packages are used, and the strength and weakness of four methods are described and analyzed, so Rhipe and RHadoop are proposed as a complete set of data integration model. The integration of R, which is popular for processing statistical algorithm and Hadoop contains Distributed File System and resource management platform and can implement the MapReduce programming model gives us a new environment where in R code can be written and deployed in Hadoop without any data movement. This model allows us to predictive analysis with high performance and deep understand over the big data.

국가권력의 미디어, 일본 육군성 보도부의 전쟁기록화

김지현(Kim, Jee-Hyun) 동북아시아문화학회 2018 동북아 문화연구 Vol.1 No.55

The Imperial Japan mobilized artists systematically to produce military documentary art records under the slogan of ‘paintbrush patriotism’, which means to repay the country with paintings, as Sino-Japanese War began to take shape. The paintings created at that time were acknowledged by the public through the exhibition of warfare paintings. In the process, the war was embellished as a holy war and the Newspaper Group of the Army was at the center of the state power, controlling and planning all these procedures. The Newspaper Group was established in 1919 as the Minister of the Army and was responsible for boosting the fighting spirit with the propaganda campaign, media control and censorship. In particular, it suggested that the war of ideology and the was of weapons were considered as the same and recognized the necessity for a state organization which controls the unified propaganda policy. Art existed to promote the power effectively. From the point of view of power and art, the military as the principal agent of the state power, was the patron to artists and provided them with painting supplies, recommended models and locations, and proposed painting themes. This paper examines the roles and purposes of the military record paintings which were produced under the policy of the military record paintings of the Newspaper Group of the Army. It considers the art which was urged by the country, and examines the collection of battle pictures of GHQ and the process of transferring to the USA from October 1945 to July 1951. It also reviews the continuity of the nature of war which emerges from the cutoff of creating war paintings.

항공운송기업의 기업분할

김지현 ( Jee-hyun Kim ),김남곤 ( Nam-gon Kim ) 한국항공경영학회 2017 한국항공경영학회지 Vol.15 No.5

기업의 자본구조에 대한 이론 연구인 Modigliani and Miller(1958)의 연구는 정보와 거래비용이 없는 상태에서 기업의 구조는 기업가치와 무관련할 수 있다는 근거를 제시한다. 이들의 이론을 기업 구조조정이나 기업분할의 연구에 적용하면, 기업이 합병을 하거나 분할을 하더라도 기업가치는 결과적으로 동일하게 유지되어야 한다. 반면에, Jensen and Meckling(1976)은 기업분할이 기업가치를 증가시킬 수 있는 이론적 근거를 제시하였다. 이들의 이론에 따르면 기업분할로 인하여 경영 인센티브가 개선되거나 주주가 경영 성과를 모니터링 할 수 있게 되면 기업을 다른 회사로 분리함으로써 운영 효율성이 향상되어 기업가치가 높아질 수 있다. 본 연구는 기업분할을 진행한 항공운송기업의 분할 사례를 이용하여 분할결정 공시일 당일 및 공시일 전후의 주가 초과수익률 및 누적초과수익률을 살펴봄으로써, 항공운송산업에 속하는 기업에 대한 주가반응이 타산업 또는 2000년부터 2016년 사이에 기업분할을 공시한 전체 표본과 비교하여 차이점이 있는지를 분석하였다. 분석 결과, 분할 목적 및 산업 등과 상관없이 공시일 당일에는 유의한 양(+)의 초과수익률이 관찰되었다. 한편, 공시일 전후의 누적초과수익률은 지주사 전환 목적에서 기업분할을 결정한 항공운송의 경우는 음(-)의 값을 나타내었다. 이는 동일 목적으로 분할을 결정한 타산업, 상이한 목적으로 분할을 결정한 타산업 및 전체표본, 부채비율이 높은 특성군 표본을 분석한 결과에서는 양(+)의 값이 나타난 것과 상이한 결과이다. 이러한 연구 결과는 기업분할이 주가에 미치는 영향력을 분석함에 있어서 산업별·기업별 특성에 따른 분석이 필요함을 시사해 준다. 따라서 투자자들은 기업분할 이벤트를 이용한 투자전략을 수립함에 있어서 분할 자체를 호재성 이벤트로 받아들이는 것이 아니라 기업의 현황, 해당 산업의 업황 등 복합적 요소들을 종합적으로 고려해야 할 것이다. 기업들은 지주회사 전환을 통한 대주주의 지배력 강화 및 경영권 방어를 위해서 기업분할을 이용할 수 있다. 따라서 본 연구는 분할을 계획하고 있는 기업에도 도움이 될 수 있을 것으로 기대된다. According to Modigliani and Miller(1958), without contracting costs and taxes, the firm value is independent of the structure of its liability and equity. Modigliani and Millers's capital structure irrelevance hypothesis suggests that the merger, acquisitions and divestiture could not affect the value of a firm. However, the concepts presented in work such as Jensen and Meckling(1976) suggest one reason why corporate divestitures might create wealth. If the divestitures improve managerial incentives or better enable shareholders to monitor managerial performance, then the separation of a corporation into different pieces can improve the efficiency of operations and thereby increase the combined value of the assets. This study deals with a corporate divestiture strategy of the airline, pursuing adoption of a holding company system. We compare the abnormal return and cumulative abnormal return of the airline around the divestiture announcement day and compare with those of divestiture companies in other industries in pursuing both the same and different purposes and with those of all the companies announcing divestiture during the period of 2000 to 2016. Empirical results show that all the divestiture announcements are significantly positively related with the abnormal return on the announcement day. The cumulative returns before and after the announcement day, on the contrary, exhibit differently in each situation. The CAR around the announcement day shows negative value with the airline case, while it shows positive value with the cases of the divestiture companies in other industries and with all sample cases listed on the KOSPI market with divestiture announcements. Similar results are observed for the divesture companies with high debt-to-equity ratio. These findings suggest that we need to take into consideration which industry the divestiture company is in when analyzing the influence of spin-off announcements on stock prices. Investors need to consider this when establishing their trading strategies and to understand the complexity of the divestiture event on stock price. We also expect that the results can provide implication for the companies planning for corporate divestitures.

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