멀티미디어 서비스에 적용 가능한 적응 변조 및 부호화 기법

신인식,오정훈,김영수,서덕영,김진상 경희-다반 ASIC 설계교육센터 2005 경희-다반 ASIC센터 논문집 Vol.6 No.-

적응 변조 기법은 통신 채널의 환경 변화에 따라 가장 적당한 변조기법을 선택하여 평균 전송 오류율을 정해진 값 이하로 유지하면서도 단일 변조 기법에 비해 더 많은 정보량을 전송하는 방법이다. 본 논문에서는 변조 기법을 선택하기 위한 스위칭 문턱 값을 최적화하여 실제적으로 전송 가능한 이론적인 최대 정보 전송량을 보장하는 기법을 채용한 적응변조 기법을 소개하고 그 성능을 단일 변조 기법 및 적응 변조 기법과 적응 부호화 기법을 사용했을 때의 성능을 비교 고찰한다.

경계층 난류박리의 제어에 관한 연구 : 제1보;매끄러운 2차원 디퓨저 벽면에서의 난류박리특성 First Report;Turbulent Separation Characteristic on the Smooth 2-Dimensional Diffuser Wall Surface

신정관,박종일,이한영,김경훈 경희대학교 산학협력기술연구원 1995 산학협력기술연구논문집 Vol.1 No.-

The structure of the turbulent wall layer developing into flow separation was studied. The experiments were performed to find out the formation of turbulent separation lead to diverging of the diffuser wall in a two-dimensional asymmetric diffuser which was attached to a downstream end of a long straight channel to provide a fully-developed turbulent inlet condition. First report, this is to estimate how to develop the region of the separation in the smooth diffuser wall with diverging condition and then is the reference on the characteristics of rough diffuser wall being under discussion at second report. As a result, static pressure profile of the fixed wall are in accord with the static pressure profire of the movable wall. Separation has broken out at the diffuser open angle θ=7o, while the diffuser openingangle is increasing, the region of the separation is advanced at the upstream and separation appears at the diffuser open angle θ=12o in the fixed wall too.

전국 농업기상관측망 구축과 농업기상정보 서비스 개발

신재훈,이계엽,이정택 한국농업정보과학회 2000 농업정보과학 Vol.2 No.1

This paper introduces the Agrometeorological Network and Information System. Twenty-one Automatic Weather Station (AWS) installed in Regional Agriculture Technology Center (ATC) were integrated into a network system based on the Internet. Also, this system was connected to the Korea Meteorological Administration (KMA) with high speed network for acquisition of data from national weather observation offices. In addition, daily agricultural climate data which had been compiled in 92 ATCs in the past 30 years were computerized into an integrated climate database. Bnsed on this database system, three main information services were developed. These are: a) real-time weather information including current agricultural weather condition at ATC and KHTA office by geographic maps as well as table format, b) climate database with search-ing and comparative analysis menus, and c) climate analysis infermation for farmers, such as greenhouse heat-ing requirement calculator, soil water content calculator, and growing degree days calculator.

DSP 보드를 이용한 OFDM 모뎀 구현

오정훈,신인식,김영수,서덕영,김진상 경희-다반 ASIC 설계교육센터 2005 경희-다반 ASIC센터 논문집 Vol.6 No.-

본 논문에서는 무선 멀티미디어 서비스를 위해 요구되는 고속의 데이터 전송에 적하한 Orthogonal frequency Division Multiplexing(OFDM) 모뎀을 Texas Instrument(TI)사의 범용 DSP 프로세서인 TMS320C6701을 기반으로 한 PCI/C6701 보드를 이용해서 소프트웨어로 설계하였다. 모듈은 크게 보드를 제어할 수 있는 타겟 프로그램과 호스트 프로그램으로 구성되며, 타겟 프로그렘은 IEEE 802.11a Wireless LAN 규격 시스템으로 이루어지고, 호스트 프로그램은 타겟 프로그램의 다운로드와 BSP 프로세서에 의해 처리된 데이터의 디스플레이 또는 저장으로 이루어진다.

Al-Mg합금(Al-5wt%Mg-3wt%Zn-1wt%Mn)의 T6 열처리에 따른 미세조직 및 기계적 특성변화

유정훈,신기삼,허성강,김정민 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

Al-Mg base alloys are attractive for aircraft. automobile and leisure applications because of their properties of low density, high intensity and wear resistance. The effect of Zn and Mn on the properties was studied in an Al-Mg base alloy. After T6 heat-treatment, the change of the microstructure and mechanical property was examined. Our investigations show that after T6 heat-treatment, the elongation was improved. The microstructures are investigated by TEM, which shows that the size of Al6Mn, Al57Mn12 phase is 100~500nm, and it also appears presence of the very small size MgZn₂ phase about 30nm.

중소규모 사업장 근로자의 직무스트레스로 인한 결근, 조퇴 현황과 한국형직무스트레스 하부요인과의 관련성

김정훈,박신구,김동현,김환철,임종한,이의철,이동훈,이지영 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

목적: 중소규모 사업장 근로자들의 직무 스트레스로 인한 결근, 조퇴의 현황과 한국형 직무 스트레스 하부 요인과의 관련성을 알아보고자 하였다. 방법: 중소규모 사업장 83곳 근로자들에 대해 한국형 직무스트레스요인 평가도구-단축형(KOSS-SF)과 사회 일반적 특성, 직업적 특정 및 직무스트레스로 인한 결근이나 조퇴 경험여부 등을 묻는 구조화된 자가 기입식 설문을 실시하였고, 응답한 4,350명에 대해 최종 분석을 시행하였다. 직무스트레스로 인한 결근, 조퇴와 한국형 직무스트레스 하부 요인들과의 관련성을 확인하기 위하여 로지스틱 회귀분석을 시행 하였다. 결과: 직무 스트레스로 인한 결근, 조퇴를 한 근로자는 남자에서 7%(196명), 여자에서 8%(113명) 로 조사되었고 한국형 직무 스트레스 하부요인과의 관련성에서는 남, 여 모두 직무요구, 관계갈등, 조직체계, 보상부적절, 직장문화 영역의 스트레스가 높은 군에서 통계적으로 의미있게 직무스트레스로 인한 결근, 조퇴율이 증가하였다. 결론: 중소규모 사업장 근로자들의 직무 스트레스로 인한 결근, 조퇴와 한국형 직무 스트레스 하부요인과의 관련성은 남자에서는 조직체계 영역이 가장 높았고, 여자는 직장문화 영역에서 가장 높은 관련성을 보였다. Objective: The aim of this study was to examine the actual conditions of absence and early leave due to job stress of 4,350 workers in 83 small and medium scale industries, and its relationship to job stress factors using Korean Occupational Stress Scale-Short Form (KOSS-SF). Methods: A structured self-reported questionnaire was used to assess each respondent's Sociodemographics, job stress, experience of absence and early leave due to job stress. Seven KOSS-SF domains of job stress were used. We estimated the relation of absence and early leave due to job stress and job stress factors using logistic regression analyses. Results: Absence or early leave due to job stress occurred in 7% of male workers and 8% of female workers. Multiple regression analysis revealed a significantly positive association job stress-related absence/early leave and job demand, interpersonal conflict, organizational system, lack of rewards and occupational climate. Conclusions: Absence and early leave due to job stress is significantly attributed to organizational System and lack of reward for men, and occupational climate and organizational system for women.

반발경도법에 의한 혼화재 및 섬유사용 콘크리트의 압축강도 추정

김정섭,신용석,노성열,김정훈 朝鮮大學校 建設技術硏究所 2007 建設技術硏究 Vol.27 No.2

This study aims to estimate strength approximate to actual concrete strength by presenting appropriate rebound method strength estimation expression with admixtures (fly ash, blast furnace slag, silica fume) which are used as cement substitute and polypropylene fiber and steel fiber and owing to their s of cement owing to their equal conditions to blending characteristics of concrete used for domestic structures and their recyclable properties. In case of rebound hammering, equation by Japanese Architecture Society was estimated 26~40% higher than destructive strength and remaining suggested equation was estimated 2%~18% lower. In case of ultrasound velocity, equation by Japanese Architecture Society was estimated 4%~11% higher than destructive strength till 60 days of age, but as age progresses, is estimated to 15% lower than destructive strength and remaining suggested equation was estimated 3%~27% lower than destructive strength in almost age. In case of complex methods, all suggested equations were estimated to 24%~94% higher than destructive strength. Since application of existing expression of normal concrete against concrete using admixtures and fiber causes error rate, this study suggests the following estimation expression depending on the kind of admixtures and fiber of concrete using them and position of non-destructive experiment. C-N f_(cu)=1.6R-25.43(R²=0.90), C-FA f_(cu) = 1.07R-8.76 (R²=0.82), C-BF f_(cu)=1.46R-23.09(R²=0.92) C-SF f_(cu) = 1.55R-22.96(R²=0.89), C-PP f_(cu) = 1.16R-12.24(R²=0.73), C-S f_(cu)=0.99R-8.07(R²=0.86)

반건식-백필터에 의한 소각배가스 중의 HCI, SOx 제거 (Ⅱ)

배병훈,신남철,조정구,문종익,임경택 동아대학교 환경문제연구소 1998 硏究報告 Vol.21 No.2

A combination of process modification and various additives to a lime-based spray-dryer/fabric-filter system was evaluated for its value in promoting sorbent utilization and simultaneous removal of HC1 and SO₂ from waste incineration flue gas. The variety of operating conditions were tested to evaluate important factors such as spray drying reactor(SDR) outlet temperature, retention time, molar equivalence ratio( MER ), fabric filter velocity, etc. For the sorbent activity enhancement, additives such as KmnO₄, NaOH, NaHCO₃, CaCl₂, a mixture of NaOH and CaCl₂ were added to Ca(OH)₂ at optimum operating condition. The mixture of NaOH and CaCl₂ ( 2 : 1 by weight ) was found to be the best economic additive. When that additive, 10% of Ca(OH)₂ by weight, was added, under the condition of Ca(OH)₂ of MER 1.0, HCl/SO₂ removal efficiencies at fabric filter were 98.3% and 97.1%, respectively.

사용자 중심의 프리스트레스트 콘크리트 교량의 해석 및 설계 프로그램 개발

김태훈,최정호,신현목 成均館大學校 科學技術硏究所 2000 論文集 Vol.51 No.1

In this paper, computer program NEO-PCBRG, was developed to analyze and design the prestressed concrete bridges. NEO-PCBRG based on the finite element method can predict the response of PSC bridges throughout their various stages of construction and service load history. NEO-PCBRG also possess both pre- and post-processing capabilities. Pre-processing refers to all of the necessary steps required to prepare a virtual prototype, more commonly termed a varied model for analysis. Post-processing is the phase of an analysis in which results from the numerical analysis are reviewed and interpreted. In order to make these sequential procedures effective, computer graphic with Visual Basic programming language is used. In conclusion, this study presents a new software architecture for analysis using user-oriented design technique.

다단토양층을 이용한 하수처리에 관한 연구

손대희,정윤철,신정훈,정진영,안대희 한국물환경학회 2004 한국물환경학회지 Vol.20 No.3

The sewages produced from small villages, rural community, drinking water reservation area and park which doesn't have sewage piping system can be caused a serious water pollution at the restricted areas. The objective of this research was to suggest an economical and effective sewage treatment method by investigating the removal of the organics, nitrogen, and phosphorus in the multi-soil-layering reactor. Soil, natural zeolite, and iron slag were used as a supporting media of multi-soil-layering in this research. The purpose of natural zeolite addition was to maintain the consistent ammonium exchange capacity by providing a sequential environment, and that of iron slag addition was to remove phosphorus by adsorption. Continuous experiment of lab-scale single-soil-layering (S-1), multi-soil-layering (S-2), and mixed-soil-layering (S-3) methods were studied to compare and optimize three different types of the reactors. The organic removal efficiencies showed more than 90% in all three reactors. While S-1 and S-3 reactors showed about T-N removal of 31%, 45%, respectively, the average T-N removal efficiency of the S-2 reactor represented an 87%. In conclusion, that results suggest that the multi-soil-layering reactor could be effectively utilized as a plant for treatment of small village sewage.