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Analysis of Structural and Thermal Parameters for Evaluating Fire Resistance of Steel Beams (철골보의 내화시간 평가를 위한 구조 및 열적 변수해석)

  • Park, Han Na;Ahn, Jae Kwon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
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    • v.21 no.6
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    • pp.609-618
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    • 2009
  • This paper proposes a versatile formula which can be used to evaluate the fire resistant time of steel beams under various design conditions. Towards this end, the key parameters which affect the fire performance of steel beams were first determined through thermo-mechanical considerations, and classified into two groups: structural parameters and thermal parameters. Then the degree of influence of each parameter on the fire performance was investigated through a fully coupled thermo-mechanical analysis up to the occurrence of run-away deflection. The accuracy of the numerical model used was verified using an available full-scale fire test before conducting an extensive parametric analysis. Multiple linear regression analysis was performed to obtain the formula which can be used to predict the fire resistance time of steel beams under various design conditions. The statistical analysis showed that the proposed formula is very robust. The application of the formula in practical fire design under the current code was illustrated in detail. The economy and other advantages of the proposed formula were clearly shown.

Feasibility Tests for Treating Fine Suspended Solids from Mining Drainage, using Various Media by Column Methods - A Case from H Coal Mine (광산배수 부유물질 저감을 위한 다양한 여과 매질의 특성 및 적용성 평가 - H 석탄광산 배수)

  • Lee, Sanghoon;Kwon, HyukHyun;Oh, Minah;Lee, Jai-Young;Kim, DukMin
    • Journal of Soil and Groundwater Environment
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    • v.17 no.6
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    • pp.112-118
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    • 2012
  • Fine suspended solids from mine drainage draw attentions due to their potential adverse influences on the water quality, such as increasing turbidity and degrading aesthetic landscape. Currently, sand filter beds are adapted in some mine drainage treating systems. However, more efficient system is in demand, as the existing sand beds reveal some problems, such as frequent maintenance intervals. Various filtering mediums including fly ash, mine tailing aggregates and the sand were tested for improving the current system, using column experimental set-up. Mine drainage samples were collected from the current treating systems in the abandoned H coal mine. The experiment was run for 7 days. Suspended solids recorded as 100.9 mg/L and the value exceeds the current standard, 30 mg/L. Sand was proved to still be the optimum medium for the fine suspended solids, compared to fly ash and fly ash + sand. Mine tailing aggregates were placed at the exit of the columns, substituting gravels. The tailing aggregates is made by mine tailings and clay. Sand bed filters can also be improved by mixing granular activated carbon, which was found to be economical and efficient in the batch experiment, conducted at the same time.

Numerical and Experimental Study on Motion Response of 1MW OTEC Platform (1MW OTEC 구조물의 운동 응답에 대한 수치 및 모형시험 연구)

  • Kwon, Yong-Ju;Nam, Bo Woo;Kim, Namwoo;Jung, Dong-Ho;Hong, Sa Young;Kim, Hyeon-Ju
    • Journal of Ocean Engineering and Technology
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    • v.31 no.2
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    • pp.81-90
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    • 2017
  • The 1MW OTEC (Ocean Thermal Energy Conversion) platform was designed for application in equatorial seas. In this study, the OTEC platform was investigated using numerical and experimental methods. An octagon-shaped OTEC platform was investigated using the Ocean Engineering Basin of KRISO. These experiments included various tests of regular waves, irregular waves and irregular waves with current (wave+current). The responses of the platform in regular waves showed good agreement between the numerical and experimental results, including the motion RAO, wave run up, and mean drift force. The peak period of heave and pitch motions were observed around 0.5 rad/s, and the effect of the total reflection was found under short wave conditions. The standard deviation (STD) of the platform motion was checked in irregular waves of equatorial and Hawaiian seas. The STD of the pitch was less than $4^{\circ}$ different from the operability requirement under equatorial conditions and the surge STD of the wave frequency showed good agreement between the numerical and experimental results. The STD values of the surge and pitch were increased 66.6% and 92.8% by the current effects in irregular waves, but the pitch STD was less than $4^{\circ}$ under equatorial conditions. This study showed that the STD of the surge was affected by spring effects. Thus, the watch circle of the platform and tension of the mooring lines must be evaluated for a specific design in the future.

Dynamic Analysis on the Construction of the Innovative City (혁신도시 건설에 관한 동태적 분석)

  • Lee, Man-Hyung;Kim, Yeon-Sik;Kim, Mi-Sung;Hong, Sung-Ho
    • Korean System Dynamics Review
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    • v.8 no.2
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    • pp.141-173
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    • 2007
  • In Korean context, the innovative cities imply new towns or urban clusters in the Non Capital Regions, all of which would accommodate the relocated Capital based public organizations. The central government-initiated innovative cities have provoked pros and cons towards their effectiveness and efficacy for the balanced territorial development. From a broader prospective, this paper firstly examines the current status quo of the innovative cities. Based on their master plans, it analyzes physical and non physical factors which would exert significant impact on the innovative cities. Secondly, it pays attention to how key factors strengthen or weaken their behavioral patterns in terms of dynamic location and implementation policies of the innovative cities. Using System dynamics approaches, it sets up couples of scenarios, categorizing between supporting and opposing arguments towards the innovative cities. Lastly, after divulging systematic structure of the innovative cities, it proposes a series of practical alternatives which would contribute to minimizing unexpected side effects or unwanted social cost in the long run. In order to guarantee reinforcing structure of the innovative cities, the paper suggests that QOL (quality of life) variables, which would require continuous investment in the social infrastructure, are pivotal in achieving original goals of the innovative cities. Otherwise, the innovative cities would not be innovative per se. In the worst case, they might be degraded into the unpopular ghost towns.

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Egypt's Science and Technology Parks Outlook : A Focus on SRTACity (City for Scientific Research and Technology Applications)

  • Abdel-Fattah, Yasser R.;Kashyout, Abdel-Hady B.;Sheta, Walaa M.
    • World Technopolis Review
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    • v.2 no.2
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    • pp.96-108
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    • 2013
  • Egypt has been known as the light house of science and innovation not only in the Middle East but to the world across ages. Recently, there have been many ups and downs that positioned Egypt in a lower rank that it actually deserves according to its long history. This review entitles the current condition of science, technology and innovation in Egypt and the consequent setting up of best practices of science and technology parks (STPs) experiences. Egypt's science, technology and innovation (STI) system is highly centralized and dominated by the public sector, with R&D happening mostly in state-run universities and research centers supervised by the Ministry of Higher Education and Ministry of Scientific Research. R&D indicators state that Egypt ranking is 40th worldwide for the published articles (around 10,000 papers in 2011), while the numbers of issued patents (350 local and 50 international in 2011) is still far beyond expected. STPs in Egypt are addressed in this review by three examples; smart village in Cairo, Investment zone in Borg El-Arab City and Technology Valley in Ismailia. The three models are discussed in details and a suggested road map for developing more STPs is estimated.

A Study on the Clothing and Purchase Behavior for the Handicapped

  • Han, Myung-Suk;Ahn, Jung-Sook
    • The International Journal of Costume Culture
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    • v.12 no.2
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    • pp.121-128
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    • 2009
  • The goal of this study is to investigate the current conditions of apparels for the handicapped, identify the problems and recommend what are appropriate and functional apparels for the handicapped. The research method was to statistically process a survey on 200 handicapped by frequency analysis and cross tabulations. The study results are as follows. First, the degree of discomfort in daily activities was shown during toilet use and eating. Among clothes categories owned by the handicapped, most discomfort was felt in the order of everyday clothes, workout clothes, underwear, athletic shoes and working clothes. Second, children's clothing was most commonly preferred clothing style by handicap for the dwarfism. Comfortable clothes was preferred and relaxed, decent, and unique styles were preferred in the order. Soft feeling texture and absorbency was considered important as preferred clothing material. Third, sizes and designs were improvements wanted by the handicapped in apparel in the order. In addition, they wanted to wear apparel sensitive to the fashion just like the non-handicapped without showing the handicapped parts. There is a necessity for the government or municipalitiesto establish and run protected workplaces or independent workplaces for those who have studied apparel. The field is thought to require continuous and numerous follow-up studies such as researches on different physiques, standardization of apparel, segmentation of sizes and methods of producing custom apparel by function and handicap.

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Design and Implementation of Adaptable User Interfaces Generation System for Diverse Devices (다양한 장치를 위한 적응력 있는 유저 인터페이스 생성 시스템의 설계 및 구현)

  • Kim, Chi-Su;Kim, Young-Tae
    • The KIPS Transactions:PartD
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    • v.12D no.7 s.103
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    • pp.979-984
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    • 2005
  • Many web-based Information systems require degrees of adaptation of the system's user interfaces to different client devices, users and tasks. We describe a new approach to providing adaptable client interfaces for web-based Information systems that allow a developer to specify a web-based interface using a high-level mark-up language. At run-time this single interface description is used to automatically provide for multiple web devices This approach allows developers to much more easily construct and maintain web-based user interfaces than other current approaches.

Numerical Simulation of Flow around a Fixed Semi-submersible Offshore Structure Using the Modified Marker-density Method (수정된 밀도함수법을 이용한 고정된 반잠수식 해양구조물 주위 유동의 수치시뮬레이션)

  • Ha, Yoon-Jin;Lee, Young-Gill;Jeong, Kwang-Leol;Yang, In-Jun
    • Journal of the Society of Naval Architects of Korea
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    • v.53 no.1
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    • pp.1-9
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    • 2016
  • It is important to research and understand the physical phenomenon around a semi-submersible offshore structure on waves and currents because the wave run-up and load occurs owing to the waves and currents. In this study, the numerical simulations are performed about flow around a fixed semi-submersible offshore structure. The Modified Marker-density method is adopted in the present computation procedure, this method is one of the various methods to define the free-surface. The present computation results are compared with existing experimental and numerical simulation(VOF method) results. And, the computation results are relatively coincident with the existing results of model test and numerical simulation by VOF method.

Development and Test results of the Dielectric Evaluation System for a Helium Gas Cooled HTS Cable (헬륨가스 냉각 고온초전도 케이블의 절연특성 평가 시스템 개발 및 성능평가)

  • Kwag, Dong-Soon;Rodrigo, Horatio
    • Progress in Superconductivity and Cryogenics
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    • v.14 no.1
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    • pp.25-29
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    • 2012
  • The novel type of cable under consideration is cooled by gaseous Helium at elevated pressure. Helium is known for having poor electric breakdown strength; therefore the dielectric capabilities of this type of cable must be tested under conditions similar to the envisaged operation. In order to study the dielectric performance we have designed and built a novel high pressure cryostat rated at 2.17 MPa which has been used for testing model cables of lengths of up to 1 m. The cryostat is an open system where the gas is not re-circulated. This allows maintaining a high purity of the gas. The target temperature range is between 40 K and 70 K. This substantially increases the critical current density of the HTS compared to 77 K, which is the typical temperature of cables cooled by liquid nitrogen. The cryostat presented allows for adjusting the temperature and keeping it constant for the time necessary to run a complete dielectric characterization test. We give a detailed description of the cryostat. Measurements of partial discharge inception voltages as well as the temperature distribution along the model cables as a function of time are presented.

The Incentive Effect and Issues of Sales Promotions in Consumer Decision Making (구매의사결정과정에서 판매촉진의 인센티브 효과와 문제점)

  • 이미화;여정성
    • Journal of Families and Better Life
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    • v.21 no.4
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    • pp.41-53
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    • 2003
  • The purpose of this study is to understand and verify the incentives as an important market environment and to help consumers use them effectively, and consequently to improve the consumer welfare. This study examined the representative incentive, the sales promotions which can effect on the consumer decision making process and current issues of them. For the purpose, a coffee specialty store was hypothesized and the subjects were 20∼30 years old, since the sales promotions can be more effective toward the younger consumers making their decisions low-involvement goods and services. The conclusions can be summarized as follows; Consumers understand the advantages and disadvantages of sales promotion very well, and use them rationally and usefully to maximize their satisfaction. the sales promotions act as incentives in the all steps of decision making processes. Generally, consumers prefer to get things at a good price, so in this survey, the discount coupons and the point accumulative membership had more effect than others. Consumers pointed out controversial issues of the sales promotions as follows: the sales promotions could bring about cost rising and unnecessary and/or impulse buying, and stir up speculative motivation. These are common serious problems in the sales promotions. The sales promotions are very useful tools in promoting sales but not fundamental in the long run. Marketers and manufacturers should keep it in mind that the best way to satisfy the consumers is to keep all things in good quality and moderate price.