• 정보보호학회논문지
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• 제15권4호
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• pp.101-105
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• 2005

2002년 Zheng은 대각행렬을 이용한 공개키 암호시스템을 소개하였다. 그러나 이 시스템은 근본적으로 안전성에 문제가 있었다. 이러한 문제점을 보완한 새로운 공개키 암호시스템을 소개하려고 한다. 이 시스템은 합성수 상의 합동다항식의 해를 구하는 것과 조르단 형식의 행렬을 이용한다.

• 디지털융복합연구
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• 제12권9호
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• pp.219-223
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• 2014

최근 무선통신 시스템의 기술이 발전함으로 M2M(Machine-to-Machine)이 산업분야에서 관심이 되고 있다. 기기간 통신인 M2M은 재난, 안전, 건설, 보건복지, 기상, 환경, 물류, 문화, 국방, 의료, 농.축산 등 사람의 접근이 어려운 공간 등에 설치되어 운용된다. 이는 사람을 대신해 장비들이 자동으로 상황에 맞추어 통신을 하고 어느 정도의 조치는 자동으로 취해지도록 함으로써 사람을 대신한 정보 관리 및 장비 운영을 할 수 있다. M2M이 디바이스간 통신이 무선으로 이루어지는 경우 공격자의 공격에 노출되어 운영되는 보안적 문제로 정당한 장치인지 상호인증 등 적절한 보안이 필요하다. 관련하여 최근 보안적으로 안전한 많은 프로토콜이 연구 되고 있으며 본 논문에서는 M2M 보안문제를 해결하기 위하여 SessionKey, HashFunction, 및 Nonce 를 적용하였으며 보안취약성을 보완한 안전한 프로토콜을 제안한다. 제안프로토콜을 기존의 대부분의 연구처럼 수학적 정리증명으로 안전함을 주장하지 않고 Casper/FDR을 이용하여 정형검증 하였으며 실험결과 제안프로토콜이 안전함이 확인되었다.

• 대한간호학회지
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• 제29권6호
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• pp.1273-1283
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• 1999

This study was done to explore the effects of dance therapy on pulmonary and cognitive functions in the elderly. The design of this study was a non-equivalent pre-post test experiment. The subjects consisted of elderly persons living in a facility located in Kyoungi-Do. Fifty eight subjects had normal cognition, sensory function and resting blood pressure. They underwent tests of pulmonary and cognitive function as baseline data before dance therapy, and at 6th week and at the end of 12nd week after following dance therapy. Twenty seven elderly persons were assigned to the experimental group and participated with the dance therapy. This therapy was based on the Marian Chace's dance therapy and Korean traditional dance with music. The dance therapy consisted of 50 minutes session, 3 times a week for 12 weeks. One session consisted of warming-up, expression, catharsis, sharing and closing stage. the intensity of the dance therapy was at the 40% of age-adjusted maximum heart rates. Data were analyzed with mean, standard deviation, Chi-square test, unpaired t-test, repeated measures ANOVA, and Bonferroni multiple regression using SAS program. The results were as follows : 1. Pulmonary function(forced expiratory volume at one second and forced vital capacity) of the experimental subjects significantly increased over time more than that of the control subjects. 2. The experimental group had significantly higher score for pulmonary function than the control group at the 12nd week after dance therapy. 3. Cognitive function of the experimental subjects significantly increased over time more than that of the control subjects. 4. The experimental group had significantly higher score for cognitive function than the control group at the 6th week and 12nd week after dance therapy. The findings showed the dance therapy could be effective in improving the pulmonary and cognitive function of the elderly.

• 보건행정학회지
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• 제18권3호
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• pp.41-57
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• 2008

To examine the gap between physician's perceived importance and performance of care and to identify factors associated with the gap. A self-administered questionnaire survey was conducted with 91 physicians working in a University hospital in Seoul. The respondents were asked about their perceived importance and actual performance of interpersonal care on a 5-point Likert-type scale, indicating a higher score as higher importance and performance. Interpersonal care was measured by questions modified from the Korean Standard Service Quality Index, which are grouped into 6 categories: basic services, extra services, reliability, courtesy, convenience, and tangibles. Multiple regression analysis was conducted to find out physician characteristics associated with the gap. All of the 6 interpersonal care categories showed lower performance than perceived importance. The respondents tended to have a worse performance than perceived importance as the number of patients per outpatient care session ($\beta$=-0.0204, p<0.05) and the need for customer satisfaction education increase ($\beta$=-0.2226, p<0.05). Female physicians ($\beta$=0.2336, p<0.05) and those with higher job satisfaction($\beta$=0.0096, p<0.05) showed a better performance than perception. Overall, it appears that lower quality of interpersonal care was delivered to patients than the desired level considered by the responding physicians. Based on the regression analysis results, it is suggested that reducing patient volume per session, fulfilling education need for customer satisfaction, and improving job satisfaction may contribute to reduce the gap between physician's perceived importance and performance of interpersonal care.

• 융합정보논문지
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• 제10권11호
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• pp.40-46
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• 2020

금융권 공동 오픈 플랫폼 구축·서비스에 따라 스타트업 생태계에 안전한 보안 기술이 요구되고 있다. 금융권 표준 오픈 API는 상호인증 과정의 핵심 API 인증키 보호를 위해, 결제 관련 핀테크 기업이 추가 보안 기술을 개발/적용하는 것을 권고하고 있다. 본 연구는 다중 채널을 사용하는 강화된 API 보안 프로토콜을 제안한다. 기존 오픈 API 관련 연구의 문제점과 취약점을 추가 분석하고, 이기종 플랫폼의 호환성을 고려하여 설계되었다. 기존 보안 프로토콜의 단일 채널에 추가 보안 채널을 분리하여 은닉하는 방법을 적용했다. 성능 분석 결과 다중 채널의 통신 세션 양방향 안전성과 강화된 인증키의 중간자 공격 안전성을 확인하였으며, 다중 세션에서 지연시간의 연산 성능(1초 이하)을 확인하였다.

• 한국통신학회논문지
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• 제28권1B호
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• pp.1-10
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• 2003

IEEE 802 3ah에서 표준화가 진행되고 있는 EPON은 하나의 OLT와 다수의 ONU가 수동소자에 의해 트리 구조로 연결되므로 도청, 위장, 가용성 등의 보안 위협을 포함한다 본 논문에서는 EPON에서 보안 위협으로부터 망을 보호하고 안전한 데이터 전송을 보장하기 위해 MAC 계층에서 인증 및 비밀성 서비스를 제공하는 보안 프로토콜을 설계하였다. 설계된 보안 프로토콜은 효율적인 키관리를 위하여 공개키 기반 인증 및 키관리 프로토콜을 이용하며, 비밀성 서비스를 위하여 최근 표준화된 AES의 Rijndael 알고리즘을 채택하였다. 제안된 인증 및 키관리 프로토콜은 인증과 공개키 교환을 동시에 수행하며, 공개 난수를 전송하여 공통의 암호키를 생성하는 안전한 프로토콜이다. 키관리의 구현을 위하여 인증 및 공개키 교환 절차, 세션키 변경 절차, 키복구 절차 등을 제안하였다. 제안된 프로토콜을 검증하기 위하여 알려진 세션키, 전향적 비밀성, 미지키 공유, 키손상 위장 등의 안전성을 분석하였다.

• 한국통신학회논문지
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• 제37권7B호
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• pp.536-549
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• 2012

무선 애드 혹 네트워크는 제한된 에너지를 갖고 있는 노드들에 의해 자율적으로 구성되는 기반 구조가 없는 네트워크이다. 노드가 갖는 이런 제약사항은 데이터 전송 시 에너지 고갈로 데이터 전달이 갑작스럽게 실패하는 상황을 초래한다. 정적인 무선 애드 혹 네트워크를 대상으로, 에너지 예약 기법 및 다중 경로 라우팅 기법을 이용하여 네트워크 내 노드들의 잔여 에너지가 적은 경우에도 안정적 데이터 전송을 지원하는 PAMP가 제안되어 있다. 본 논문은 PAMP에 다중 경로를 설정하는 과정에서 네트워크 코딩 기회가 있는 경로를 우선적으로 선정하여 중간 노드의 에너지를 절약할 수 있는 기법을 추가할 것을 제안한다. 시뮬레이션을 통한 성능 분석에서 본 논문에서 제안하는 기법이 기존의 PAMP와 센서 네트워크에서의 에너지 인식 다중 경로 설정 기법인 REAR에 비해 패킷 전송 성공률이나 노드의 에너지 소비에 있어서 우수한 성능을 보이고 있다.

• Archives of Plastic Surgery
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• 제49권5호
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• pp.676-682
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• 2022

Background Virtual education is an evolving method for teaching medical learners. During the coronavirus disease 2019 pandemic, remote learning has provided a replacement for conferences, lectures, and meetings, but has not been described as a method for conducting a cadaver dissection. We aim to demonstrate how learners perceive a virtual cadaver dissection as an alternative to live dissection. Methods A virtual cadaver dissection was performed to demonstrate several upper extremity nerve procedures. These procedures were livestreamed as part of an educational event with multimedia and interactive audience questions. Participants were queried both during and after the session regarding their perceptions of this teaching modality. Results Attendance of a virtual dissection held for three plastic surgery training institutions began at 100 and finished with 70 participants. Intrasession response rates from the audience varied between 68 and 75%, of which 75% strongly agreed that they were satisfied with the virtual environment. The audience strongly agreed or agreed that the addition of multimedia captions (88%), magnified video loupe views (82%), and split-screen multicast view (64%) was beneficial. Postsession response rate was 27%, and generally reflected a positive perspective about the content of the session. Conclusions Virtual cadaver dissection is an effective modality for teaching surgical procedures and can be enhanced through technologies such as video loupes and multiple camera perspectives. The audience viewed the virtual cadaver dissection as a beneficial adjunct to surgical education. This format may also make in-person cadaver courses more effective by improving visualization and allowing for anatomic references to be displayed synchronously.

• Medical Lasers
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• 제8권1호
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• pp.13-18
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• 2019

Background and Objectives High-intensity focused ultrasound (HIFU) can produce small zones of thermal damage. A HIFU procedure is non-invasive and it can achieve rejuvenation of facial skin. Fractional CO₂ laser resurfacing delivers thermal damage to the pixilated columnar zone of the skin and so evoke collagen remodeling, the same as HIFU. In many cases, the patients who want rejuvenation with HIFU are also good candidates for cutaneous photorejuvenation such as can be accomplished via fractional CO₂ resurfacing. If patients are treated in a single session by remodeling both the superficial and deep compartments of skin by using both modalities, then improvement in rhytides and tightening of sagging skin will optimize the aesthetic result. Materials and Methods Between May 2014 and January 2018, a total of 44 patients were treated with combination HIFU and fractional CO₂ laser resurfacing according to our protocol. First, the HIFU was applied to the entire face with an average of 300 treatment lines. Immediately after HIFU treatment, the ultrasound gel was washed off and then fractional CO₂ laser resurfacing was performed. We evaluated the patients using 4-point grading scales. The clinician examined the skin for evidence of complications after the completion of treatment. Results All the patients' skin quality showed improvement. Further. the clinical results after duel modality treatment were substantially better than that after the use of either modality alone. The recovery times and the incidence of adverse events when quickly and consecutively performing both treatments were similar as compared to those with employing stepwise treatment. We encountered no complications whatsoever. Conclusion When compared with stepwise therapy, combination therapy with HIFU and fractional CO₂ resurfacing offers better, safer and more effective clinical results. Thus, for targeting multiple layers of aging facial skin, this combination therapy can be safely performed in a single treatment session.

• 디지털산업정보학회논문지
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• 제12권2호
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• pp.15-24
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• 2016

GPS(Global Positioning System) location tracking is a method for taking the precise coordinates after the coordinates are obtained by a GPS receiver, and displaying them on the map. In this paper with WAVE(Wireless Access for Vehicular Environment) simulation, we show that various services such as vehicle tracking service, real-time road conditions service and logistics can go tracking service, control and operation services according to the vehicle position and the traveling direction by using the GPS position data. A vehicle tracking system using GPS is automatically able to manage multiple RCP when exchanging data between RMA and the RCP, and it provides rapid requests and responses. To verify that multiple sessions between RMA and RM, as well as multiple sessions between RMA and RCP are able to be implemented, we take RMA as a RCP application on an OBU, until the RMA is receiving data response from corresponding RM. As a result of this experiment, we show that the response speeds of single session between RMA and RM using 1, 2, 3, and 4 kbyte unit data are similar, 62.32ms, 62.65ms, 63.02ms, and 63.48ms, respectively. Likewise, those of 128 muliple sessions using 1, 2, 3, and 4 kbyte unit data are not much more time difference, 298.08ms, 302.21ms, 322.85ms, and 329.62ms, respectively.