유비쿼터스 통합 커뮤니케이션 플랫폼의 VoIP 시스템 설계

최재원,Choi, Jae-Won 한국정보통신학회 2009 한국정보통신학회논문지 Vol.13 No.1

통합 커뮤니케이션(Ubiquitous/Unified Communication) 플랫폼은 인터넷폰(VoIP), 이메일, 통합메세징, 인스턴트 메시징, 웹컨퍼런싱, 화상회의 등의 다양한 멀티미디어 통신수단을 제공한다. 본 논문에서는 통합 커뮤니케이션 플랫폼의 주요 기능과 구조를 소개하고, PSTN 전화망과의 연동으로 전화망 사용자와의 통화서비스를 지원하는 VoIP 시스템의 구현을 위 한 기능분석과 설계에 관해 연구하였다. The Ubiquitous/Unified Communication Platform supports various multimedia communication tools such as VoIP, Email, Unified Messaging, Instant Messaging, Web Conferencing, Audio/Video Communication etc. In this paper we introduced the main functions and architecture of the Unified Communication Platform and we researched on the function analysis and design of the VoIP System that supports PC-to-PBX/PSTN Phone and PBX/PSTN Phone-to-PC communications through the connectivity and interoperation with PSTN.

B-ISDN 프로토콜 내장의 멀티미디어통신용 IP-PBX 시스템 구현

최재원,Choi, Jae-Won 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.12

본 논문에서는 인터넷으로 연결된 컴퓨터를 이용하여 전화교환 및 멀티미디어통신이 가능하도록 하는 B-ISDN 기반의 IP-PBX 시스템의 구현에 관해 연구하였다. 기존 정보통신 교환시스템의 구조상의 문제점 개선을 위한 IP-PBX 시스템의 구조를 설계하고, 호제어를 위한 메세지와 자료구조의 정의와 상태천이를 설계하였고, 사용자간 통화를 위한 착발신 단말 간의 호제어와 사용자통신을 구현하였다. In this paper we researched on the implementation of the B-ISDN protocol embedded IP-PBX System with the computers interconnected by the Internet for the telephone exchange and multimedia communication. For the improvement on the structural problems of the previous PABX we designed the structure of the IP-PBX System, defined message and data structure for call control, designed call control state transition and implemented call control message flows for user's communication.

Active-Active 방식의 DNS 서버의 이중화 구축 및 결함내성 시험

최재원,Choi, Jae-Won 한국정보통신학회 2013 한국정보통신학회논문지 Vol.17 No.1

본 논문에서는 기존의 Active-Standby 방식의 이중화가 아닌 Active-Active 방식의 DNS (Domain Name System) 이중화에 관해 연구하였다. Active-Active 방식의 DNS 이중화를 위해 1, 2차 DNS 서버 간에는 rsync와 crontab을 이용하여 주기적으로 복사하여 동일한 상태를 유지하고, 1차 혹은 2차 DNS 서버가 장애로 인해 정지되더라도 살아 있는 DNS 서버가 계속해서 서비스를 지속하도록 하였다. Active-Standby Duplication Techniques are conventionally used for fault-tolerant systems. But in this paper we researched on the Active-Active Duplication Techniques for Fault-tolerant DNS System. Our Active-Active Duplication made the 1st DNS periodically copied to the 2nd DNS and maintained the same status by using Rsync and Crontab. Even though the 1st or the 2nd DNS stops due to some critical errors, the remaining DNS can take over and provide continuous services.

PNF 패턴에서 회전요소에 관한 고찰

최재원,김미현,정현애,Choi, Jae-won,Kim, Mi-hyun,Jeong, Hyun-ae 대한고유수용성신경근촉진법학회 2003 PNF and Movement Vol.1 No.1

Objectives: The main purpose of this study is to analyze the importance of the rotatory factor in PNF pattern. In this article has to analyze and clarify the importance of the rotatory factor in PNF pattern by comparing the general concepts, facilitation technics, and neuroscience of muscle spindle, etc. Methods: This is a literature study with books. Results : There is close relationships between the pattern in PNF and rotatory factor. PNF pattern is priorily made up the diagonal and spiral pattern. the rotatory factor influences and guides from the start to end in the pattern. Conclusions : Rotation component is most important of the three component that one flexion or extension, abduction or adduction and rotation. It is that provide longer muscle length and stimulate the muscle spindles.

프로그램화 된 신체운동이 ADHD 아동의 주의산만행동과 과잉행동에 미치는 효과

최재원(Jae Won Choi),강경두(Kyoung Doo Kang),정혜연(Hye Yeon Jung) 한국사회체육학회 2012 한국사회체육학회지 Vol.0 No.47

The purpose of this study is to deeply analyze a change of the programmed physical exercise in attentiondeficient behavior and hyperactivity of children with ADHD, through the single-subject research design method. The research subjects were 4 elementary school students who are under being cured due to being judged to be ADHD at Child Psychiatric Clinic for C University Hospital where is located in Seoul at that time of beginning experiment in order to be conformed with the objective of research. For visual observation, the attention-deficient behavior was used the frequency-typed case sampling method(Shin So-yeon, Park Jaeguk, Kim Yeong-mi, Lee Hwa-eun, 2007). Observation of hyperactivity was used the contents, which Carlson and Hotfield(1991) defined, by referring to the contents by Mun Jae-gyeong(1998). The following are the results that were elicited through the research procedure of this study. First, the programmed physical exercise was indicated to reduce attention-deficient behavior in children with ADHD. Second, the programmed physical exercise was indicated to reduce hyperactivity in children with ADHD.

Java 서블릿을 이용한 웹 기반의 3-Tier 데이타베이스 시스템 설계 및 구현

최재원,Choe, Jae-Weon 한국통신학회 2003 韓國通信學會論文誌 Vol.28 No.1B

Conventional command-based communication services are rapidly substituted by multimedia web-based communication services at most recent times As the result, many valuable database and services that were developed by investing lots of human and material resources become to be useless Therefore in this paper we researched the methodologies and techniques for designing and implementing a multimedia web-based database system that made users easily access to database and services by updating the conventional command-based database services. 기존의 PC 통신 서비스가 최근 인터넷에 기반을 둔 멀티미디어 웹 서비스로 빠르게 대체됨으로 인해 과거 많은 인력과 자금을 투자하여 개발한 유용한 데이터베이스와 PC 통신 환경 상의 많은 서비스가 시장되는 사용자로부터 도외시되어 사장되는 문제가 발생하고 있다 이에 본 연구에서는 과거 PC 통신 환경 상에서 제공되었던 텍스트 위주의 명령에 기초한 데이터베이스 서비스를 사용자의 정보 접근이 용이한 멀티미디어 웹에 기초한 데이터베이스 서비스로 전환하기 위한 시스템의 설계 및 구현방법에 관해 연구하였다

이슈진단 및 분석 - 지역경제권 내의 국립연합대학원 운영모델

최재원,김수형,이해준,황영숙,박상후,Choe, Jae-Won,Kim, Su-Hyeong,Lee, Hae-Jun,Hwang, Yeong-Suk,Park, Sang-Hu 한국대학교육협의회 2014 大學敎育 Vol.184 No.-

체간 양측성 회전 운동과 PNF 운동이 부정렬 증후군을 가진 성인의 보행에 미치는 영향

최재원,노현정,Choi, Jae-Won,No, Hyun-Jeung 대한고유수용성신경근촉진법학회 2011 PNF and Movement Vol.9 No.4

Purpose : The aim of this study was to identify of bilateral trunk rotation(BTR) exercise and PNF exercise on gait in the individuals with malalignment syndrome. Methods : Subjects were 32 that were divided 2 groups in 20's generation. Interventions were trunk ratation exercise and PNF exercise. We used Medex for trunk rotation exercise. BTR group received exercise for three-sets (10min/set) along with stretching exercise ten-minutes, 3 times per week. PNF group took turns the D1 pattern in upper extremity and the D1 pattern in the opposite side of lower extremity for three-sets (10min/set). The measurement were force metatarsal 1 (FM 1), impulse metatarsal 1 (IM 1), force heel lat (FHL), impulse heel lat (IHL) by using footscan (RS scan). Statistical method was repeated measurement of ANOVA and p value was 0.05. Results : BTR and PNF group were significantly different in time(FM 1, IM 1, FHL, IHL). As different of right/left, BTR and PNF exercise were significantly different in FM 1, IM 1, FHL. Conclusion : BTR exercise was good exercise for malalignment but needs expensive equipment, for example, Medex. PNF exercise doesn't need expensive equipment but good method in malalignment syndrome person for gait ability. If PNF exercise is more experiment, PNF exercise could use variety for more patients.

비인두암 환자에 대한 세기조절 방사선치료 시 이용되는 MVCT와 kV-CBCT의 수정체 흡수선량 평가

최재원,김철종,박수연,송기원,Choi, Jae Won,Kim, Cheol Chong,Park, Su Yeon,Song, Ki Weon 대한방사선치료학회 2013 대한방사선치료학회지 Vol.25 No.2

목 적: 비인두암(Nasopharyngeal cancer) 환자를 세기조절 방사선치료(IMRT)시 영상유도 촬영(MVCT & kV-CBCT)에서의 수정체 흡수선량(absorbed dose)을 평가하고자 한다. 대상 및 방법: 인체모형팬텀(Anderson rando phantom, Alderson Reserch Laboratories Inc., USA)을 대상으로 전산화 단층촬영(lightspeed ultra 16, General Electric, USA)을 실시하였고 획득되어진 이미지를 비인두암 환자의 치료계획에 동일한 조건으로 토모세라피 치료계획장치(Tomotherapy, Inc, USA)와 선형가속기 치료계획장치(Pinnacle 8.0, philips Medicle System)로 동일하게 수립하였다. 열형광선량계(TLD100 Harshaw USA)를 수정체 위치에 위치시키고 토모세라피 MVCT를 세 가지 조건(fine, normal, coarse)에서 촬영, kV-CBCT를 두 가지 조건(low dose head, standard dose head)에서 각각 좌우 3번씩 반복 측정하였다. 결 과: 토모세라피와 선형가속기를 이용하여 실시한 MVCT와 kV-CBCT 촬영 시 수정체의 흡수선량을 측정한 결과 토모세라피 MVCT에서 coarse의 경우 RT 0.8257 cGy, LT 0.8137 cGy, normal의 경우 RT 1.089 cGy, LT 1.188 cGy, fine의 경우 RT 2.154 cGy, LT 2.082 cGy라는 결과를 얻을 수 있었다. 선형가속기 kV-CBCT에선 standard mode의 경우 RT 0.2875 cGy, LT 0.1676 cGy, Low-dose mode의 경우 RT 0.1648 cGy, LT 0.1212 cGy로 나타났다. MVCT와 kV-CBCT의 최대 차이는 약20배 이상인 것을 알 수 있다. 결 론: kV-CBCT가 MVCT을 통해 영상유도 이미지를 얻는 것보다 수정체 흡수선량만으로 고려하였을 때 세기조절 방사선 치료 시 환자가 치료 이외에 받는 선량을 줄일 수 있다고 판단된다. 또한 동일한 치료 장비라 하더라도 다양한 촬영조건에 따라 선량차이가 있다는 것을 알 수 있다. Purpose: Quantitative comparative evaluation of the difference in eye lens absorbed dose when measured by MVCT and kV-CBCT, though such a dose was not included in the original IMRT treatment plan for the nasopharyngeal cancer patient. Materials and Methods: We used CT (Lightspeed Ultra 16, General Electric, USA) against an Anderson rando phantom (Alderson Research Laboratories Inc, USA) and established the plan for tomotherapy treatment (Tomotherapy, Inc, USA) and linear accelerator treatment (Pinnacle 8.0, Philips Medicle System) for the achieved CT images on the same condition with the nasopharyngeal cancer patient treatment plan. Then, align the ther-moluminescence dosimeter (TLD100 Harshaw, USA) with the eye lens, shot the lens with Tomotherapy MVCT under 3 conditions (Fine, Normal, and Coarse), and shot both lenses with kV-CBCT under 2 conditions (Low Dose Head and Standard Dose Head) 3 times each. Results: When we analyzed the eye lens absorbed dose according to MVCT and kV-CBCT images by using both Tomotherapy and Pinacle 8.0, we achieved the following result; According to Tomotherapy MVCT, RT 0.8257 cGy in the Coarse mode, LT 0.8137 cGy, RT 1.089 cGy and LT 1.188 cGy in the Normal mode, and RT 2.154 cGy and LT 2.082 cGy in the Fine mode. According to Pinacle 8.0 kV-CBCT, RT 0.2875 cGy and LT 0.1676 cGy in the Standard Dose mode and RT 0.1648 cGy and LT 0.1212 cGy in the Low-Dose mode. In short, the MVCT result was significantly different from that of kV-CBCT, up to 20 times. Conclusion: We think kV-CBCT is more effective for reducing the amount of radiation which a patient is receiving during intensity modulated radiation treatment for other purposes than treatment than MVCT, when we consider the absorbed dose only from the viewpoint of image-guided radiation therapy. Besides, we understood the amount of radiation is too sensitive to the shooting condition, even when we use the same equipment.

로드 밸런싱 Active-Active 방식의 웹 서버 이중화 구축 및 결함내성 시험

최재원,Choi, Jae-Won 한국정보통신학회 2014 한국정보통신학회논문지 Vol.18 No.1

본 논문에서는 Active-Active 방식의 웹서버 이중화 방법에 관해 연구하였다. Rsync과 crontab을 이용하여 웹서버간에 주기적인 복사가 이루어지도록 하여 동일한 상태를 유지시켰다. 로드밸런싱서버가 웹서버를 교대로 실행하여 부하를 분산하고, 빠른 서비스가 제공되도록 하였다. 또한 임의의 웹서버에 장애가 발생하더라도 또 다른 웹서버에 의해 서비스가 계속 유지되도록 하였다. In this paper we researched on the Duplication Techniques for Active-Active Web Servers. Rsync and crontab utilities make copy periodically between web servers and maintain the same status. Load Balancing Server makes web servers load balanced and fast servicing by executing web servers alternatively. Even though one web server stops due to some critical errors, the remaining web server can take over and provide services continuously.