이동통신분야의 표준화 전망

안재민,김은정,An, Jae-Min,Kim, Eun-Jeong 한국정보통신기술협회 2007 TTA저널 Vol.109 No.-

고속 패킷 데이터 서비스를 위한 cdma2000 무선접속 기술

안재민 에스케이텔레콤 (주) 2003 Telecommunications Review Vol.0 No.-

이동통신망을 통한 데이터 서비스의 제공은 여러 가지 측면에서 한계를 갖고 있다고 할 수 있다. 특히 음성 위주의 서비스를 근간으로 하고 있는 기존 이동통신은 패킷 형태의 트래픽 특성을 갖고 있는 데이터 서비스를 수용하기에 더욱 많은 한계를 보일 수 밖에는 없다는 점에서 이동통신망에서의 패킷 데이터 서비스에 대한 회의론이 등장하기도 한다. 그럼에도 불구하고 이동통신이 갖고 있는 사용 편의성과 서비스의 연속성, 그리고 이에 기인한 넓은 사용자 층을 바탕으로 이동통신망을 통한 고속 패킷 데이터 서비스를 제공하기 위한 기술 개발은 여전히 이루어지고 있다. 본 논문에서는 이동통신망에서 패킷 데이터통신을 제공하기 위한 기술들을 살펴보면서 이러한 기술들이 cdma2000 방식의 무선접속 기술에 어떤 형태로 나타나 있는지에 대하여 살펴보고자 한다.

폐광산 인근 지역에서 생산되는 농산물의 중금속 오염도 평가

안재민,장순영,황향란,박대한,이봄내,김샛별,이광희 한국환경농학회 2020 한국환경농학회지 Vol.39 No.1

BACKGROUND: This study was to carry out risk assessment of contamination of cadmium (Cd), lead (Pb), and inorganic arsenic (I-As) in agricultural products of 25 crops from the abandoned mine areas. The 36 typical investigation sites located in Gyeongbuk provincial area were selected by considering the heavy metal levels, that had been known that the amount of the heavy metals exceeded the contamination level based on the previous survey. METHODS AND RESULTS: Cadmium, lead, and total arsenic (T-As) concentrations were determined using microwave device and ICP-MS. Inorganic arsenic was determined by HPLC-ICP-MS. The limits of quantification for heavy metals were 0.59 μg/kg for Cd, 0.42 μg/kg for Pb, 0.55 μg/kg for T-As, and sum of As (Ⅲ) (1.74 μg/kg) and As (Ⅴ) (2.25 μg/kg) for I-As, respectively. The contents of Cd, Pb, and I-As (only rice) were N.D.-0.958 mg/kg, N.D.-0.227 mg/kg, and 0.082 mg/kg, respectively, in the agricultural products. For risk assessment, dietary exposures of heavy metals through usual intake were 5.20×10-4-7.15×100 μg/day for Cd, 7.00×10-5-7.75×10-1 μg/day for Pb, and 1.17×101 μg/day for I-As, taking 0.01-14.37%, 0.01-2.05%, and 15.16% as risk indices, respectively. CONCLUSION: It requires to consider the critical levels of heavy metals in agricultural products due to unexpectedly high levels in a few places, while concentrations of heavy metals in the samples were relatively low in most areas. .

RF Magnetron Sputtering법으로 $BaTiO_3$ 박막 증착시 $O_2/Ar$비가 박막의 특성에 미치는 영향

안재민,최덕균,김영호 한국세라믹학회 1994 한국세라믹학회지 Vol.31 No.8

Structural and electrical properties of BaTiO3 thin films deposited on Pt/SiO2/Si substrates by RF magnetron sputtering method have been investigated. Crystallization behavior and electrical properties were studied for the films deposited under various sputtering gas compositions (Ar+O2 gas mixture) and substrate temperatures. All the films deposited above 50$0^{\circ}C$ were all crystallized and their preferred orientation changed from (001) to (111) with the addition of oxygen gas. The dielectric constant of films deposited in pure argon was about 110 and showed little dependence on the substrate temperature. But that was increased as the ratio of O2/Ar increased and its substrate temperature dependence was discernible. The highest dielectric constant reached to 550. In addition, the films deposited in mixed gas showed stable dielectric properties against the frequency and temperature.

Sputtering법에 의한 $BaTiO_3$ 박막의 상형성에 관한 연구

안재민,최덕균,김영호 한국세라믹학회 1993 한국세라믹학회지 Vol.30 No.8

BaTiO3 sputtering targets of 3 inch diameter were prepared by sintering the CIP (Cold Isotatic Pressing) compacts at 136$0^{\circ}C$ for 3hrs. The apparent density and grain size were 97% and 30${\mu}{\textrm}{m}$, respectively. After BaTiO3 films were deposited on Si and Pt/Ti/SiO2/Si substrates using these targets, films were annealed at various conditions and the crystallization behavior, reaction with the substrate and the electrical properties were investigated. The films on both substrates required 5~20hrs furnace annealing for crystallization at the temperatures from $600^{\circ}C$ to 80$0^{\circ}C$. For the films on Si substrate, interaction between the film and the substrate was suppressed upt o $700^{\circ}C$ for 10 hrs and the relative dielectric constant was 30. As the annelaing temperature and time were increased, the relative dielectric constants of the films decreased due to the formation of silicate phases through the reaction with the substrate. For the BaTiO3 films on Pt/Ti/SiO2/Si substrate, the reaction with the substrate was further reduced when the annealing condition was identical to that for Si substrate, but the reaction between the layers in Pt electrode took place above $700^{\circ}C$. When the films were annealed at $600^{\circ}C$ where the stability of Pt electrode was sustained, relative dielectric constant was increased to 110 since the reaction with substrate was effectively reduced even for a longer annealing time and the crystallization was enhanced.

견봉쇄골관절 완전탈구에서 수술적 치료후 발생한 후유증(원인규명 및 예방에 대하여)

안재민,박희전,황성관,차지환 대한골절학회 1988 대한골절학회지 Vol.1 No.1

The conservative treatment such as splinting, bandaging and harnessing in the partial disruption of the acromioclavicular joint(Grade II or less) has been successuful, but many surgeons prefer to operative treatments for complete A-C dislocation(Grade III). Though more than 55 operative methods of treatment were reported in the literature, they could be divided into four categories: 1) acromioclar reduction and acromioclavicular fixation, 2) acromioclavicular reduction, coracoclavicular ligament repair, and coracoclavicular fixation, 3) distal clavicle excision, and 4) muscle transfers. Among numerous operative methods, we used Weaver Dunn technic, A-0 tension Band technic, and Modified Bosworth technic in total 28 cases of complete A C dislocation from March 1984 ta June 1988 at the Yonsei University Wonju College of Medicine, Wonju Christian Hospital. In most cases, excellent or good results were obtained, but we still found several postoperative complications. We experienced neither deep wound infection nor osteomyelitis. All 6 cases had fixation-related complications. After close examination of operation notes and X-rays, following suggestions were considered; 1. Reduce every A-C joint anatomically before inserting K-wires through A-C joints. 2. Start shoulder motion several days after operation to provide enough time for healing of deltoid and trapezius muscles. 3. Surgenous play a major role to prevent complications such as malposition oi' fixatives and incomplete A-C joint reduction.

맞춤형 진로교육을 위한 웹기반 SMTS의 설계와 구현

안재민,박대우,An, Jae-Min,Park, Dea-Woo 한국정보통신학회 2010 한국정보통신학회논문지 Vol.14 No.10

고등학교에서 학생의 진로교육에 대한 기본 자료는 교육과학기술부에서 지원하는 NEIS의 교무업무시스템과 담임교사 중심의 진로교육 자료가 오프라인 형태로 관리 및 운영되고 있어, 학생들의 진로교육을 위한 실질적 의사결정 시스템으로서 활용하기에 어려움이 있다. 본 논문에서는 학생들의 맞춤형 진로교육을 위한 e포트폴리오, 성적 및 상담자료 등을 DB로 구축하여, 인터넷 웹 기반의 학생관리통합시스템(SMTS: Student Management Total System)을 설계하고 구현한다. 이 결과 교사들은 학생의 소질과 적성을 고려한 맞춤형 진로교육을 실시하여, 건전한 직업관을 가진 미래의 국가자원으로 성장시키고자 하는데 그 목적이 있다. As basic data about students' career education in high school are being managed only in forms of NEIS, which is supported by Ministry of Education, Science and Technology, and the information for career education that homeroom teachers have operated by off-line system, it is hard to use them as practical decision support system for students' career education. In this study, we intend to design and embody web-based Student Management Total System by constructing DB of students' e-portfolios, school records and counselling data etc. As a result, teachers can carry out vocational education that is considered students' talents and aptitude, and we have a goal for promoting the growth of the students as the national human resources who have sound occupational consciousness through this education.

골반골절의 해부학, 분류 및 방사선학

안재민,서정탁 대한골절학회 2013 대한골절학회지 Vol.26 No.3

TG-4G Air Interface

안재민 한국컴퓨터통신연구회 2001 OSIA Standards & Technology Review Vol.15 No.1

3GPP/3GPP2 국제 표준화 활동

안재민 한국컴퓨터통신연구회 2002 OSIA Standards & Technology Review Vol.17 No.1