지하 무선 CDMA 망의 전파 측정 및 Micro BTS의 성능 분석

안호중,노재성,조성언,조성준 한국항공대학교 1998 論文集 Vol.36 No.-

지하 무선망에서 CDMA(Code Division Multiple Access)시스템의 용량과 품질은 다중 사용자 간섭과 임펄스성 간섭의 영향을 받는다. 그러므로 CDMA 시스템에서는 간섭을 최소화하려는 연구가 필요하다. 최근에는 서비스 영역을 확대하기 위한 방법으로 지하 공간 또는 음영 지역에서 LCX(Leakage Coaxial Cable)가 이용되고 있다. 본 논문에서는 지하 무선 CDMA 망의 전파의 세기를 측정하였다. 그리고 측정된 결과를 이용하여 이론적인 Micro BTS의 성능을 분석하였다. 이론적인 BER 해석을 위하여 지하 무선 CDMA 망의 임펄스성 간섭 모델을 제안하고, 측정된 파라미터 값을 이용하여 Micro BTS의 BER 성능을 구하였다. 측정 결과, 지하철이 없을 경우보다 지하철이 운행함에 따라서 임펄스성 간섭이 중대됨을 알 수 있었으며, 단방향 운행보다 양방향 운행에서 임펄스성 간섭이 더욱 증가하였다. 수치 계산을 통하여 임펄스성 간섭의 발생 시간율과 다중 사용자 수에 따라 Micro BTS의 BER 성능이 주로 열화됨을 알 수 있었다. The capacity and quality of CDMA(Code Division Multiple Access) system are affected by multi user interference and impulsive interference in the underground wireless network. Therefore, it is essential to minimize the interference in CDMA system. Recently, LCX (Leaxial Cable) is used to expand service area in the underground area or shadow region. In this paper, the propagation of underground wireless CDMA network is measured. And then, using the measured data the theoretical performance of Micro BTS(Base Transmitter Station) is analyzed. For theoretical BER analysis, the impulsive interference model in the underground wireless CDMA network is proposed and the BER performance of Micro BTS is obtained by using the measured data. From the measurement results, it is found that the impulsive interference increases in the presence of passing train than the absence of passing train. Also, it is known that more interference appears in the presence of crossing two way train than in the presence of passing one way directional train. From the numerical results, the BER performance of Micro BTS is to be mainly degraded by the occurrence rate of impulsive interference and the number of multiple users.

Three-Dimensional Porous Collagen/Chitosan Complex Sponge for Tissue Engineering

Kim, Sung Eun,Cho, Yong Woo,Kang, Eun Jung,Kwon, Ick Chan,Lee, Eunhee Bae,Kim, Jung Hyun,Chung, Hesson,Jeong, Seo Young The Korean Fiber Society 2001 Fibers and polymers Vol.2 No.2

A three-dimensional, porous collagen/chitosan complex sponge was prepared to closely simulate basic extracellular matrix (ECM) constitutes, collagen and glycosaminoglycan. The complex sponge was prepared by a lyophilization method and had the regular network with highly porous structure, suitable for cell adhesion and growth. The pores were well interconnected, and their distribution was fairly homogeneous. The complex sponge was crosslinked using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to increase its boilogical stability and enhance its mechanical properties. The crosslinking medium has a great effect on the inner structure of the sponge. The homogeneous, porous structure of the sponge was remarkably collapsed in an aqueous crosslinking medium. However, the morphology of the sponge remained almost intact in a water/ethanol mixture crosslinking milieu. Mechanical properties of the collagen/chitosan sponge were significantly enhanced by EDC-mediated crosslinking. The potential of the sponge as a scaffold for tissue engineering was investigated using a Chinese hamster ovary cell (CHO-K1) line.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)

김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1

In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

2003년 국내 중증급성호흡기증후군 진료 현황 및 문제점 분석

이진수,김은실,정문현,백제중,정선화,안주희,최영화,이선희,고철우,김성범,김민자,박승철,기현균,송재훈,최상호,김양수,이상오,조용균,박영훈,정숙인,김연숙,이흥범,손창희,장성희,정희진,김우주 대한감염학회 2004 감염과 화학요법 Vol.36 No.3

목적 : 2002년 말 중국에서 SARS가 발생한 이후 국내에서도 2003년 10월까지 총 3명의 추정환자, 17명의 의심환자가 보고되었다. 향후 추가적인 SARS의 유행이 우려되는 상황에서, 그간의 SARS 환자 진료에 있어서의 실질적인 준비사항, 진료 현황 등에 대한 조사를 통해 문제점을 파악하여, 향후 더 나은 대비가 될 수 있도록 개선점을 제시하고자 하였다. 재료 및 방법 : SARS로 의심되는 환자를 진료 경험이 있는 병원의료진을 대상으로 2003년 10월에 설문조사를 실시하였다. 설문에는 SARS 환자 진료 시의 실질적인 조치, 진료 현황, 병실, 응급실 및 외래에서의 격리 시설과 준비사항, 보건당국의 관리와 지원에 관한 사항을 포함하였다. 결과 : 대상이 되는 22개 병원 중 17개(17/22, 77.2%) 병원이 설문에 응하였다. SARS 환자를 위한 격리실은 응급실, 외래, 일반병실 및 중환자실에서 각각 9개(9/17, 52.9%), 5개(5/17, 29.4%), 15개(15/16, 93.7%), 4개(4/16, 25%) 병원에서 음압처리가 되어있지 않은 일인실 혹은 다인실이 사용되었고, 1개(1/16, 6.3%) 병원에서만 일반병실에서 음압격리실이 운영되었다. 입원환자의 진찰 시 개인보호구의 착용은 거의 모든 의료기관에서 이루어졌다. 보건당국에서 SARS지정병원의 시설 등을 사전에 확인한 곳은 1곳(1/12, 8.3%)이였고, 14개 병원(14/15, 93.3%)에서는 보건당국에 의뢰한 검사결과를 통하 받지 못하였다. 결론 : 의료기관에서 SARS 환자용 격리실뿐만 아니라 기존의 격리실 설비 등이 미흡하였으며, 특히 중환자실 및 외래의 준비가 더욱 부족하였다. 보건당국의 의료기관에 대한 종합적인 지원이 부족하였고, 병원과의 원활한 연계가 잘 이루어지지 않았다. SARS 만이 아닌 격리를 필요로 하는 질환의 적절한 진료를 위해 향후 병원 시설의 정비와 정부차원에서의 보다 구체적이고 실질적인 대책마련이 필요하다. Background : There was an worldwide outbreak of the Severe Acute Respiratory Syndrome (SARS) originated from China in late 2002. During that period three cases of suspected SARS and 17 cases of probable SARS were reported in Korea. With the concerns about the reemergence of SARS-coV transmission, it is important to be prepared for any possibility. So, this study is aimed to analysis the past measures in managing SARS and propose the amendatory plans to improve the preparedness. Materials & Methods : Questionnaires were collected among clinicians with any experience in managing the probable or suspected SARS cases in Oct. 2003. 17 out of 22 hospitals responded to the questionnaire. The contents in the questionnaire were practical activities, personal equipments, response plans, isolation facilities in emergency centers, outpatient clinics, general wards and intensive care units, and relationship with the public health department. Results : The dedicated isolation rooms in emergency centers, outpatient clinics, general wards, and intensive care units were prepared in 9 (9/17, 52.9%), 5 (5/17, 29.4%), 15 (15/16, 93.7%), and 4 (4/16, 25.0%) hospitals, respectively. Except for one hospital that newly made negative pressure room for SARS, single or multi-bed rooms without airborne infection control were used in all the other hospitals. The personal precaution principles were kept quite well in general wards. Before the designation of SARS hospital by the public health department prior evalution to see if the hospital was suitable for managing SARS was conducted in only 1 (1/12, 8.3%) hospital. The results of laboratory diagnosis were reported back in 1 (1/15, 6.6%) hospital. Conclusions : The isolation facilities which can control airborne infection were almost deficient not only for SARS but also for other respiratory transmissible diseases. For the infection control of transmissible diseases including SARS, more investment is needed on medical facilities and comprehensive support from the public health department required.

선형 최적제어 관측기와 결합된 다항식 급수분석(Ⅱ)

曺明鉉,鄭盛夫 瑞逸專門大學 1992 論文集 Vol.10 No.-

신경회로망을 이용한 자기신뢰도를 갖는 스마트 센서

조준기,이민호,반상우,성정훈,이덕동 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

In this paper, we propose a new smart sensor scheme using neural networks. The proposed smart sensor automatically generates not only an averaged output of a sensor but also the reliability of the outputs that have an ambiguity. We demonstrate the performance of the proposed method using computer generated data and experimental data obtained from gas sensor.

취성재료의 미소압입시 균열전파의 유한요소해석

조성산,이정현 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.1

Stress around the edge of penny-shaped lateral crack in the residual stress fields in elastic perfectly-plastic half-spaces indented by a rigid cone are analyzed using finite element technique. The stresses are characterized and interpreted to investigate the crack growth behavior with the aid of linear elastic fracture mechanics. The influence of material properties on the crack growth behavior is also examined. Continuing growth of the crack after removal of indentation load is explained based on the variation of crack growth driving force with crack size. Furthermore, it is demonstrated that the change in the crack propagation direction with the growth is due to the change in the crack growth mechanism.

악성 혈액질환에서 성공적인 동종골수이식 후 숙주 기질 미세환경의 구축

조상희,이제중,남찬은,최경상,정익주,이일권,김진희,박종태,김형준 대한조혈모세포이식학회 2002 대한조혈모세포이식학회지 Vol.7 No.1

인체의 골수는 간엽모세포를 함유하고 있으며 이들은 골수미세환경의 주된 세포들로 분화가 가능하여 조혈기능을 지지한다. 본 연구에서는 성별이 다른 동종조혈모세포이식 환경에서 조혈모세포의 완전 생착을 보이고, 이식 후 1년에서 8년이 지난 11예의 재생불량성 빈혈 및 백혈병 환자들을 대상으로 하여 골수에서 MSC를 분리하고 체외 확장을 통해 배양된 MSC에서 X 염색체 탐식자를 이용한 FISH 및 microsatellite polymorphism PCR 기법으로 그 기원을 확인하였다. 그 결과 조혈모세포는 완전히 공여자 기원으로 대치되었음에도 불구하고 MSC는 모두 수여자 기원임을 알 수 있어, 동종조혈모세포이식에서 미세환경의 구축은 수여자의 자가 생산에 의한 골수 간질세포에 의한 것으로 생각된다. Background: Human bone marrow (BM) contains mesenchymal stem cells (MSC) that can differentiate into various cells of mesenchymal origin. It remains a matter of controversy whether donor-derived stromal cells are capable of engraftment following hematopoietic stem cell transplantation (HSCT) or not. Methods: To determine if donor-derived stromal cells are transferred to the recipients of allogeneic HSCT, we investigated the characterization of MSC in 11 patients 1 to 8 years after sex mis-matched allogeneic HSCT in severe aplastic anemia and leukemia. Results: All patients had complete engraftment with donor- derived stem cells as shown by detection of donor type DNA in peripheral blood mononuclear cells. Following culture, MSC showed the expression of SH2 and SH4, but none of the hematopoietic markers of CD14, CD34, or CD45. MSC which can be differentiated to osteogenic lineage showed the genotype of recipient completely using FISH or PCR analysis. Conclusion: This study confirmed that MSC isolated from recipients of allogeneic HSCT in severe aplastic anemia and leukemia are not of donor genotype despite of full hematopoietic engraftment with donor type. Donor cells did not contribute to reconstitute the marrow microenvironment.