• Title/Summary/Keyword: analytical study

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Calibration Methods for the Gas Chromatographic Analysis of ppt-level Hydrogen Sulfide (H2) in Air (환경 대기 중 ppt 수준의 황화수소 분석을 위한 GC 방식의 검량 기법에 대한 연구)

  • 김기현;오상인;최여진;최규훈;주도원
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.6
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    • pp.679-687
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    • 2003
  • In this study, we investigated the analytical techniques to quantify the ambient concentration of hydrogen sulfide (H$_2$S) in air at ppt concentration level. For this purpose, an on-line GC analytical system equipped with both pulsed-flame photometric detector (PFPD) and thermal desorption unit (TDU) was investigated by collecting ambient air samples. The results of our study generally indicated that calibration conditions of GC system is highly sensitive to affect the accuracy of the analytical technique. Most importantly. we found that the use of different matrices in the the preparation stage of working standards was sensitive to control the overall performance of this technique. The calibration of our analytical system was tested by the two types of working standard (prepared by mixing either with high purity $N_2$ or with the ambient air). According to this test, the latter represented more efficiently the detecting conditions of actual air samples. The peak occurrence patterns of both air samples and standards (prepared by mixing with ambient air) were altered in a similar manner as the function of the loaded volume; however, it was not the case for the $N_2$-mixed standards. Results of our study suggest that detection of H$_2$S is highly different from other sulfides and that its quantification requires minimiaing interfering effects of non -pure substance (like water vapor) and (either sorptive or destructive) loss effects.

The study of simplified technique compared with analytical solution method for calculating the energy consumption loads of four houses having various wall construction

  • Han, Kyu-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.1
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    • pp.46-58
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    • 2011
  • A steady-state analysis and a simple dynamic model as simplified methods are developed, and results of energy consumption loads are compared with results obtained using computer to evaluate the analytical solution. Before obtaining simplified model a mathematical model is formulated for the effect of wall mass on the thermal performance of four different houses having various wall construction. This analytical study was motivated by the experimental work of Burch et al. An analytical solution of one-dimensional, linear, partial differential equation for wall temperature profiles and room air temperatures is obtained using the Laplace transform method. Typical Meteorological Year data are processed to yield hourly average monthly values. This study is conducted using weather data from four different locations in the United States: Albuquerque, New mexico; Miami, Florida; Santa Maria, California; and Washington D.C. for both winter and summer conditions. The steady state analysis that does not include the effect of thermal mass can provide an accurate estimate of energy consumption in most cases except for houses #2 and #4 in mild weather areas. This result shows that there is an effect of mass on the thermal performance of heavily constructed house in mild weather conditions. The simple dynamic model is applicable for high cycling rates and accurate values of inside wall temperature and ambient air temperature.

Seismic response control of a building complex utilizing passive friction damper: Analytical study

  • Ng, C.L.;Xu, Y.L.
    • Structural Engineering and Mechanics
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    • v.22 no.1
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    • pp.85-105
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    • 2006
  • Control of structural response due to seismic excitation in a manner of coupling adjacent buildings has been actively developed, and most attention focused on those buildings of similar height. However, with the rapid development of some modern cities, multi-story buildings constructed with an auxiliary low-rise podium structure to provide extra functions to the complex become a growing construction scheme. Being inspired by the positively examined coupling control approach for buildings with similar height, this paper aims to provide a comprehensive analytical study on control effectiveness of using friction dampers to link the two buildings with significant height difference to supplement the recent experimental investigation carried out by the writers. The analytical model of a coupled building system is first developed with passive friction dampers being modeled as Coulomb friction. To highlight potential advantage of coupling the main building and podium structure with control devices that provide a lower degree of coupling, the inherent demerit of rigid-coupled configuration is then evaluated. Extensive parametric studies are finally performed. The concerned parameters influencing the design of optimal friction force and control efficiency include variety of earthquake excitation and differences in floor mass, story number as well as number of dampers installed between the two buildings. In general, the feasibility of interaction control approach applied to the complex structure for vibration reduction due to seismic excitation is supported by positive results.

An Analytical Approach to Derive the Quality Loss Function with Multi-characteristics by Taguchi's Quality Loss Concept (다구찌 품질손실개념에 의한 다특성치 품질손실함수 도출의 분석적 접근방법)

  • Pai, Hoo Seok;Lim, Chae Kwan
    • Journal of Korean Society for Quality Management
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    • v.48 no.4
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    • pp.535-552
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    • 2020
  • Purpose: The main theme of this study is to derive a specific quality loss function with multiple characteristics according to the same analytical structure as the single characteristic quality loss function of Taguchi. In other words, it presents an analytical framework for measuring quality costs that can be controlled in practice. Methods: This study followed the analytical methodology through geometric, linear algebraic, and statistical approaches Results: The function suggested by this study is as follows; $$L(x_1,x_2,{\cdots},x_t)={\sum\limits_{i=1}^{t}}k_i\{x_i+{\sum\limits_{j=1}^{t}}\({\rho}_{ij}{\frac{d_i}{d_j}}\)x_j\}x_i$$ Conclusion: This paper derived the quality loss function with multiple quality characteristics to expand the usefulness of the Taguchi quality loss function. The function derived in this paper would be more meaningful to estimate quality costs under the practical situation and general structure with multiple quality characteristics than the function by linear algebraic approach in response surface analysis.

Analytical Framework for Promoting Customer Participation in Benefit Delay Type Services

  • Cho, Myung-Rae
    • The Journal of Economics, Marketing and Management
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    • v.6 no.1
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    • pp.9-16
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    • 2018
  • Purpose - Benefit delay type services have a characteristic of benefit delay that does not immediately appear at the time of delivery of service. Due to a characteristic of benefit delay, the customer's participation in the service delivery system is hindered, and the quality of service declines. As a result, customer satisfaction would be reduced. The purpose of this study is to construct an analytical framework to analyze a mechanism that promotes customer participation in benefit delay type services. Research design, data, and Methodology - Existing research has considered only the performance of service companies to enhance the quality of service and customer satisfaction. This study focused on customer participation as a factor affecting the quality of service and customer satisfaction and attempted to construct an analytical framework based on a theoretical perspective of motivational research. Results - By adopting the motivation theory, this research derived three concepts, the possibility of gaining benefits, the emotional experience, and the desire of benefit. And motivation is created when the three factors interact with each other. Conclusions - This paper has constructed an analytical framework for analyzing factors that promote customer participation in the benefit delay service and finally has proposed case study for further research.

Current status of working environment monitoring the designated organization's laboratory and factors affecting reliability of the analysis results (작업환경측정 지정기관의 분석실 현황 및 분석결과의 신뢰성에 영향을 주는 요인)

  • Kim, Ki-Woong;Park, Hae Dong;Kim, Sungho;Ro, Jiwon;Hwang, Eun Song;Chung, Eun-Kyo;Cho, Kee Hong
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.28 no.1
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    • pp.108-116
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    • 2018
  • Objectives: This study investigated to the analytical work environment, analyst's expert and status of analytical instrument in the designated organization's laboratory for measuring work environment, and carried out to ensure reliability of analytical results. Methods: This study was conducted by 114 analysts who work in designated organization's laboratory for measuring work environment. Information on the working environment and personal characteristics of the analysts were collected using a self-reported questionnaire and were analyzed using the SPSS program through analysis of frequency and t-test. Results: The speciality of subjects was occupational health(57.0%), environmental health(38.6%) and environmental engineering(4.4%), and they had a higher level of academic ability than workers in other industries. Analysts had to handle a large number of sample analysis and many tasks other than analytical work. The analysts answered that it was difficult to analyze organic substances than inorganic substances, and the difficult parts were the analytical methods setting of new substances(55.3%), instrument analysis(24.6%) and principle of analysis(23.7%). Analytical instruments mainly have legally required instruments. The difficulty of the analysis is solved from the senior analyst in the laboratory and analytical information is mainly exchanged through seminar organized by the Association of Occupational Health Analysts. The analysts who are planning to move or considering the company were 48.2%, and the reasons for moving the company were difficult to work(14.0%), low salary(9.6%), employment type(8.8%) and job stress(7.0%). Conclusions: The conclusions of our study were that it was possible to secure reliability by solving the problems such as implementing professional education to improve expertise of analysts, strengthening analytical instruments through institutional improvement and improving work environment.

An Analytical Study of Shear Locking (전단과대현상에 대한 해석적 고찰)

  • ;Ma, Haitao
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.11-18
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    • 1993
  • An Analytical study of shear locking is introduced for linear thick beam element. The appropriate sampling point which eliminate shear locking phenomenon was Proposed through this study. Reduced integration point is exactly same as the sampling point obtained from this study. Numerical example indicates how shear locking is serious. some solutions for shear locking are presented.

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Analytical Study to Determine the Dynamic Property of Control Equipment Room using LRB (납-고무베어링을 적용한 제어장치의 동적평가를 위한 해석적 연구)

  • 김우범;김대곤;이경진;박병구
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.473-480
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    • 2003
  • In these days, The base isolation system is often used improve the seismic capacity of the structure Instead of conventional techniques of strengthening the structural members. The purpose of this study is to evaluate dynamic property evaluation of control equipment using Lead Rubber Bearing. In this study, analysis numerical was performed to determine the optimal dynamic property of lead rubber bearing and damper which minimize the response of base from in main control room. Also the analytical results was composed with the test results peformed in previous study

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A Comparative Study on the Determination of the Selenium in Biological Samples using 75Se and 77mSe Nuclides (75Se과 77mSe 핵종을 이용한 생물시료 중의 셀렌 분석에 대한 비교 연구)

  • Moon, Jong-Hwa;Kang, Sang-Hoon;Kim, Sun-Ha;Chung, Yong-Sam;Kim, Young-Jin
    • Analytical Science and Technology
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    • v.18 no.1
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    • pp.23-26
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    • 2005
  • Se is well known as an anti-oxidant trace element and many customers are interested in an analysis and contents of Se in the various foodstuff samples. This study was aimed at establishig and comparing an analytical method for the determination of the Se in biological samples by neutron activation analysis using two nuclides, $^{75}Se$ and $^{77m}Se$. Keeping this objective, three NIST biological standard reference materials were chosen and the concentrations of the Se were determined under the prefixed analytical conditions such as the irradiation, decay and measurement time. The measured values by both analytical methods were evaluated with certified values. In addition, the detection limits and measurement uncertainty for the analytical results using $^{75}Se$ and $^{77m}Se$ were compared with each other.

Development of the Standard Analytical Methods for Ginkgo biloba Leaf Extract (은행엽엑스 제제의 기준 및 시험법과 규격 설정)

  • Kim, Seung-Hyun;Kim, Dae-Hyun;Park, Jin-Ho;Oh, Mi-Hyune;Cho, Chang-Hee;Baek, Ju-Hyun;Cho, Jung-Hee;Kim, Tae-Bum;Lee, Ki-Yong;Kim, Young-Choong;Sung, Sang-Hyun
    • Korean Journal of Pharmacognosy
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    • v.39 no.3
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    • pp.218-222
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    • 2008
  • This study was carried out to establish standard analytical methods for Ginkgo biloba leaf extract. Ginkgo flavonoids, terpene lactones, ginkgolic acids were employed as reference compounds for analytical method. Analytical method of US Pharmacopoeia was adopted for flavonoids and terpene lactones, and a new method was developed for ginkgolic acids. Analytical methods established in this study could be applied to a reasonable and unified quality control of G. biloba leaf extract.