• Environmental Analysis Health and Toxicology
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• 제21권2호
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• pp.197-208
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• 2006

The hazards of chemicals can be classified using classification criteria that are based on physical, chemical and ecotoxicological endpoints. These criteria may be developed be iteratively, based on scientific or regulatory processes. A number of national and international schemes have been developed over the past 50 years, and some, such as the UN Dangerous Goods system or the EC system for hazardous substances, are in widespread use. However, the unnecessarily complicated multiplicity of existing hazard classifications created much unnecessary confusion at the user level, and a recommendation was made at the 1992 Rio Earth summit to develop a globally harmonized chemical hazard classification and compatible labelling system, including material safety data sheets and easily understandable symbols, that could be used for manufacture, transport, use and disposal of chemical substances. This became the globally harmonized system for the Classification and Labelling of Chemicals (GHS). The developmental phase of the GHS is largely complete. Consistent criteria for categorizing chemicals according to their toxic, physical, chemical and ecological hazards are now available. Consistent hazard communication tools such as labelling and material safety data sheets are also close to finalizations. The next phase is implementation of the GHS. The Intergovernmental Forum for Chemical Safety recommends that all countries implement the GHS as soon as possible with a view to have the system fully operational by 2008. When the GHS is in place, the world will finally have one system for classification of chemical hazards.

• 산업기술연구
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• 제21권B호
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• pp.31-35
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• 2001

The phase forming ability and formation enthalpies(${\Delta}H$) of Si-M(M = Ti, Cu, Ni, Zr) compound alloys were predicted by Miedema's model. The silicon compound alloys were synthesized by mechanical alloying and then characterized for the phase formation by X -ray diffraction. The electrochemical properties as the anode materials for lithium ion batteries were investigated using a galvanostatic method. It appears that the electrochemical characteristics of Si-M alloys can be predicted from the thermodynamic criteria for the phase formation using the Miedema's model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.171-173
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• 1991

the poly silicon film was deposited by APCVD. and then the deposition mechanism and electrical characteristics was investigated for that film. The grain phase, the deposition rate, and the etch characteristics were evaluated according to the deposition conditions. The criteria temperature of surface morphology state was $730^{\circ}C {\sim}780^{\circ}C$ between the mirror phase grain and the powder phase grain.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1937-1939
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• 1998

This paper presents a simple switching method to generate a PWM pattern mostly relevant to signle-phase three-level PWM rectifier. The adopted PWM switching pattern is performed in a manner similar to the space vector PWM method, which is popularly used in the three-phase rectifier and inverter. A set of possible voltages has been selected so that an equation with a time integral considered within a sampling period should be satisfied every sampling time. The simulation result shows that the proposed control scheme is good in some performance criteria such as unity power factor, low harmonic distortion of input current, dynamic response and voltage balancing of two series-connected DC capacitors.

• 대한기계학회논문집
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• 제10권6호
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• pp.814-822
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• 1986

본 연구에서는 이러한 점에 착안하여 비가열수직이상유동계에서 전도Probe 를 이용하여 시간평균보이드율을 측정하여 이들로부터 통계적으로 처리된 확률밀도함 수(PDF)분포와 이와 관련된 일련의 모우멘트계산을 시도 하므로써 유동양식과 천이특 성에 대하여 객관적이고 체계적인 해석을 하였다. 또한 학계 및 산업계에서는 측정 기구의 단순화가 요구되므로 전도Probe의 출력신호를 분석하여 유동양식에 따르는 특 성을 아울러 구명하였다.

• 디자인학연구
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• 제2권1호
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• pp.99-106
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• 1989

Environmental designers face a wide range of problems to be solved in their day-to-day works. The scale and number of problems and so enormous that designers should be a way out to meet these complex situation. Lately, environmental design process based on systems a.pproach is chosen for design methodology. It is a very complicated procedure with many alternatives. It is a evolutionary process that establishes the solution of a series of problems. This study attempt to tell the designer how to find design solution to problems and how to organize form as solution problems. The model of this design process is largely composed of three phases; Phase I : Problem definition and existing system analysis. Phase II : design goals and objectives, design criteria Phase III : creative process of design form.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.253-254
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• 2016

In the trend of building enlargement, high-rise and irregular shaped building, domestic application of BIM in construction phase is increasing in recent years. BIM that is based on a three-dimensional, requires a specific building expression. Model expression level required for each phase such as design, construction, and maintenance of the construction project can be different. BIM model to apply in practice is difficult because it is not clear to set up the criteria for the expression level of construction BIM model. And it has a limit that is lower productivity in construction project. Therefore, this study considers the way of the improvement and analyzes the application for representation level of construction BIM model through the survey. By analyzing of the survey results, this study will be to present a basis for an appropriate expression level setting of construction BIM model.

• Korean Chemical Engineering Research
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• 제55권1호
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• pp.130-134
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• 2017

Organic aerosols dispersed in the atmosphere likely undergo phase separation. Such internally mixed particles are often described as comprising an organic phase and an aqueous phase separately. We studied the morphology of two liquid separated aerosols in the sub-microscale by using a simple thermodynamic model with Russian doll geometry. The morphology of particles can be easily predicted from the simple criteria on the surface tension and two algebraic equations (the volume constraint and Young equation). This result may give the potential explanation about the complex morphology of the organic airborne particles.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제7권1호
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• pp.52-60
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• 1996

본 연구는 월경전기에 불편감이 있다고 응답한 230명의 여고생을 대상으로 전향적인 매일 평가서를 사용하여 월경주기에 따른 신체적, 기분, 행동변화의 양상을 보고자 하였다 '월경전 불쾌기분장애'로 확인된 군과 전체대상군 모두에서 후기황체기에 신체적 , 심리적 증상들이 뚜렷한 악화를 보이기 시작하여 월경이 시작되면서 증상의 최고치를 나타냈으며, 월경시작4일째에 급격한 감소를 보였다. 또한 월경주기중에서 특히 월경기때에 보다많이 신체적인 불편감을 경험하고 있고, 이때 월경기간이 길수록 불편감이 큰 것으로 보여진다. 이러한 양상들은 젊은 여성의 월경전기 변화 양상을 대표할 수는 없으나, 본 대상군이 여고생임을 감안할 때 우리나라 청소년의 월경주기에 따른 고유한 증상의 변화양상을 보여주는 것이라고 할 수 있겠다.

• 한국통신학회논문지
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• 제25권1A호
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• pp.10-17
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• 2000

본 논문에서는 가변 확산이득 (VSG) 구조를 갖는 멀티미디어 멀티레이트 DS/CDMA 시스템에서 PN 시퀀스의 위상에 따른 상관 특성을 보였고, 시퀀스 위상을 최적화 하였다. 멀티레이트 VSG-DS/CDMA 시스템의 경우에 시퀀스의 최적화는 동일 길이의 시퀀스들과는 물론, 다른 확산 이득을 갖는 다른 시퀀스들에 대해서 동시에 이루어져야 하므로 시퀀스의 최적화가 쉽지 않다. 따라서, 본 논문에서는 이러한 멀티레이트 시스템에서의 시퀀스 상관 특성을 살펴보았고, 이를 통해서 비트 오율을 최소화 시킬 수 있는 시퀀스 선택기준으로 MIN-AIP를 제시하였다. m 시퀀스와 Gold 시퀀스에 대한 성능분석 결과, MIN-AIP 기준에 의한 시퀀스 초기 위상의 선택기준이 성능을 가장 향상시킬 수 있는 최적의 선택기준이라는 결론을 얻을 수 있었다.