• Title/Summary/Keyword: The design cycle

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Uplift Testing and Load-transfer Characteristics of Model Drilled Shafts in Compacted Weathered Granite Soils (화강풍화토 지반에 타설된 소형 현장 타설 말뚝의 인발시험 및 하중 전이 특성)

  • 임유진;서석현
    • Journal of the Korean Geotechnical Society
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    • v.18 no.4
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    • pp.105-117
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    • 2002
  • In the design of foundations for the super-structures such as transmission towers and oil-platforms, the foundations must be considered as a medium to resist cyclic tensile forces. In this study, the uplift capacity of the drilled shaft used as the medium resisting to this pattern of forces is investigated by performing cyclic uplift test of a small model-drilled shaft constructed in compacted granite soil in a steel chamber. In this test, the behavioral difference between a pile loaded on the top of the pile and a pile loaded at the bottom of the pile was investigated intensively. The load transfer curves obtained from the test were investigated by changing the confining pressure in the chamber. The load tests also included creep test and cyclic test. It is found from the tests that uplift capacity of the shaft loaded at the bottom is greater than that of the shaft loaded on the top of the pile. It is found also from the creep test that the pile loaded at the bottom was more stable than the shaft loaded on the top. If a pile loaded at the bottom is pre-tensioned, the pile will be most effective to the creep displacement. It is found also from the cyclic tests that apparent secant modulus obtained in a cycle of the load increases with the number of cycles.

Stress and Fatigue Evaluation of Distributor for Heat Recovery Steam Generator in Combined Cycle Power Plant (복합발전플랜트 배열회수보일러 분배기의 응력 및 피로 평가)

  • Lee, Boo-Youn
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.44-54
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    • 2018
  • Stress and fatigue of the distributor, an equipment of the high-pressure evaporator for the HRSG, were evaluated according to ASME Boiler & Pressure Vessel Code Section VIII Division 2. First, from the results of the piping system analysis model, reaction forces of the tubes connected to the distributor were derived and used as the nozzle load applied to the detailed analysis model of the distributor afterward. Next, the detailed model to analyze the distributor was constructed, the distributor being statically analyzed for the design condition with the steam pressure and the nozzle load. As a result, the maximum stress occurred at the bore of the horizontal nozzle, and the primary membrane stress at the shell and nozzle was found to be less than the allowable. Next, for the transient operating conditions given for the distributor, thermal analysis was performed and the structural analysis was carried out with the steam pressure, nozzle load, and thermal load. Under the transient conditions, the maximum stress occurred at the vertical downcomer nozzle, and of which fatigue life was evaluated. As a result, the cumulative usage factor was less than the allowable and hence the distributor was found to be safe from fatigue failure.

The Effect of Social Awareness of Startup and Entrepreneurial Education on Entrepreneurial Intention: Focused on Entrepreneurship (창업에 대한 사회적인식과 창업교육이 창업의도에 미치는 영향 : 기업가 정신의 매개효과를 중심으로)

  • Bae, Jee-Eun;Kim, Soo-JIn;Lee, Phil-Soo
    • The Korean Journal of Franchise Management
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    • v.8 no.4
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    • pp.43-54
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    • 2017
  • Purpose - Recently, the meaning and importance of entrepreneurship has been emphasized in order to achieve innovation-led economic growth through entrepreneurship. Various forms of entrepreneurship education have been established centering on universities, and the scale of the entrepreneurship support programs of the government and the private sector has been increasing. Entrepreneurial education can enhance entrepreneurship and promote entrepreneurial intention. The purpose of this study is to examine the effect of experience of entrepreneuship education and social awareness of entrepreneurship on entrepreneurial intention through entrepreneurship, focusing on women who were relatively alienated from entrepreneurial activities. This study will provide suggestions for women's entrepreneurship in the future. Research design, data, and methodology - Recently, the meaning and importance of entrepreneurship has been emphasized in order to achieve innovation-led economic growth through entrepreneurship. Various forms of entrepreneurship education have been established centering on universities, and the scale of the entrepreneurship support programs of the government and the private sector has been increasing. Entrepreneurial education can enhance entrepreneurship and promote entrepreneurial intention. The purpose of this study is to examine the effect of experience of entrepreneuship education and social awareness of entrepreneurship on entrepreneurial intention through entrepreneurship, focusing on women who were relatively alienated from entrepreneurial activities. This study will provide suggestions for women's entrepreneurship in the future. Result - Recently, the meaning and importance of entrepreneurship has been emphasized in order to achieve innovation-led economic growth through entrepreneurship. Various forms of entrepreneurship education have been established centering on universities, and the scale of the entrepreneurship support programs of the government and the private sector has been increasing. Entrepreneurial education can enhance entrepreneurship and promote entrepreneurial intention. The purpose of this study is to examine the effect of experience of entrepreneuship education and social awareness of entrepreneurship on entrepreneurial intention through entrepreneurship, focusing on women who were relatively alienated from entrepreneurial activities. This study will provide suggestions for women's entrepreneurship in the future. Conclusions - Although women's economic activity is increasing, women's activities in the field of business start-up are still passive. The purpose of this study is to examine the effect of entrepreneurship on entrepreneuship education and the social perception of entrepreneurship. As a result, we found that social awareness, entrepreneurship education, and entrepreneurship all had a significant influence on the intention of entrepreneurship. Positive social atmosphere for entrepreneurship induces interest in entrepreneurship education and forms a virtuous cycle structure that fosters entrepreneurship through entrepreneuship education. In addition, the introduction of diverse programs that encourage entrepreneurship should enhance the attractiveness of promising talent to enter the entrepreneurial market.

Profiling Approach for the Choice between Speculation and Postponement Strategy in Supply Chain Management (공급사슬관리의 예측전략과 지연전략 선택을 위한 프로파일링 접근법)

  • Kang, Sung-Wook;Kim, Gyu-Bae
    • Journal of Distribution Science
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    • v.12 no.4
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    • pp.47-54
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    • 2014
  • Purpose - The postponement strategy, which delays the form, place, and production of products as late as possible, has been widely considered as a competitive supply chain management scheme in an era of mass customization and modular manufacturing. An interesting business phenomenon is that not all manufacturing/logistics firms choose the postponement strategy. Given that postponement is a counter-measure to speculation, which has some advantages under certain environments, the current imprudent inclination toward the postponement strategy may cause firms to lose the potential of the speculation strategy, an alternative strategy in supply chain management. Building on the logistics and manufacturing literature, this study examines characteristics of two contrasting strategies, postponement and speculation, and major factors favoring each strategy. Research design, data, and methodology - We apply the profiling approach to two business cases, HP printer and LG mobile phone. The profiling approach is a method of choosing a particular strategy aligned with environmental factors. While various approaches have been used to check the fit between a business strategy and environmental factors, the literature on manufacturing strategy and logistics has commonly adopted the profiling approach. Major factors used in profiling variables are derived from the literature. Two samples, HP printer and LG mobile phone, are selected, because they represent major characteristics appropriate for each strategy. The profiling is based on data from semi-organized interviews with managers. Results - The profiling approach shows that the postponement strategy is a suitable one for HP printers. Most factors, such as product life cycle, large production volume, low-price, product value, and monetary density, support delaying end products until as late as possible. Despite some exceptions, such as delivery time and economy of scale, our analysis states that the overall profile of HP printer is favorable for the postponement strategy. On the other hand, LG mobile phone may adapt the speculation strategy. Although it has large production volume and low delivery frequency, most characteristics support the speculation strategy for this product. An interesting finding is that, despite common perception that advanced technology products such as mobile telephones favor the postponement strategy, profiling proposes the speculation strategy for this product. Conclusions - Our analysis shows that speculation is not the universal option for supply chain management, and that, when choosing a specific strategy, one should consider many factors simultaneously. A major implication of our work is to emphasize the role of environmental factors such as supply chain variables in choosing an inventory strategy, and the importance of fit rather than solely strategic orientation. A theoretical contribution is to demonstrate the benefit of the simultaneous consideration of business variables in choosing specific strategies. For practitioners, our work leads us to consider the existence and the potential of speculation as a counter-measure to postponement. In addition, the comprehensive framework in this research may be instantly used in examining a practical strategy.

Characteristics of the Flux-lock Type Superconducting Fault Current Limiter According to the Iron Core Conditions (자속구속형 초전도 전류제한기의 철심조건에 따른 특성)

  • Nam, Gueng-Hyun;Lee, Na-Young;Choi, Hyo-Sang;Cho, Guem-Bae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.7
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    • pp.38-45
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    • 2006
  • The superconducting fault current limiters(SFCLs) provide the effect such as enhancement in power system reliability due to limiting the fault current within a few miliseconds. Among various SFCLs we have developed a flux-lock type SFCL and exploited a special design to effectively reduce the fault current according to properly adjustable magnetic field after the short-circuit test. This SFCL consists of two copper coils wound in parallel on the same iron core and a component using the YBCO thin film connected in series to the secondary copper coil. Meanwhile, operating characteristics can be controlled by adjusting the inductances and the winding directions of the coils. To analyze the operational characteristics, we compared closed-loop with open-loop iron core. When the applied voltage was 200[Vrms] in the additive polarity winding, the peak values of the line current the increased up to 30.71[A] in the closed-loop and 32.01[A] in the open-loop iron core, respectively. On the other hand, in the voltages generated at current limiting elements were 220.14[V] in the closed-loop and 142.73[V] in the opal-loop iron core during first-half cycle after fault instant under the same conditions. We confirmed that the open-loop iron core had lower power burden than in the closed-loop iron core. Consequently, we found that the structure of iron core enabled the flux-lock type SFCL at power system to have the flexibility.

Evaluation of Performance and Construction the New National Test Road Sites of Modified Asphalt (신설국도의 시험시공을 통한 표층용 개질 아스팔트 공용성 평가)

  • Cho, Gyu-Tae
    • International Journal of Highway Engineering
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    • v.4 no.3 s.13
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    • pp.43-49
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    • 2002
  • Asphalt pavements have to perform under the conditions of heavily-loaded vehicles due to the industrialization and large temperature variance between the summer and the winter. Due to these factors, a characteristics change of early permanent deformation becomes a big issue, and to remedy this problem many research to use modified asphalt are being widely conducted. However, most of the modified asphalt is being paved after milling the surface course and applying tackcoating, and it is being used mostly for the repair and maintenance purpose rather than pavement of new national road. The purpose of this investigation is to obtain some fundamental data for the evaluation of the performance and long-term performance of the construction material mixtures by the laboratory test and field experiments. For the field experiment, 200m of two-lanes national road, that is being paved for the new national road under the direction of Pusan Regional Construction Management Office, was paved with SBS PMA and PSMA asphalt mixtures, which are an modified asphalt mixtures used for the surface course, on top of the base course paved with other modified asphalt mixtures. The remaining section of the new national road was paved with dense grade mixture. The laboratory tests assessed and analyzed the mixture characteristics by Marshall's stability test, strength tests and wheel-tracking test. On the basis of the evaluation result of the temperature control and roughness of the newly constructed road at the field experiment site, it is desired to evaluate and identify the most economic modified asphalt mixtures by long-term performance evaluation and LCC(Life Cycle Cost) analysis in order to apply the test result to the design of new road construction in the future.

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Development of the Calorimeter to Measure Heat Rate Generated from Battery for EV & HEV (전기자동차용 축전지의 발열량 측정을 위한 열용량계 개발)

  • Yang Cheol-Nam;Park Seong-Yong
    • Journal of the Korean Electrochemical Society
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    • v.2 no.4
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    • pp.218-220
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    • 1999
  • The performance of the Electric Vehicle and Hybrid Electric Vehicle depends on that of the battery pack composed of series connected batteries. And thermal property is one of the main factors which decide the performance of the battery pack. So heat generation rate from the battery under the various driving mode must be measured as precise as possible because thermal characteristics of the battery affect the driving performance and battery pack's life cycle. Besides, to design and develop the battery thermal management system for the EV and HEV, the measurements of the thermal properties of the batteries are needed. However, the established calorimeter is not adequate to test an EV's battery because its cavity is too small to accommodate the EV's battery. Therefore we developed the calorimeter to test the thermal property of the EV's battery. Its cavity size is 120mm long, 75mm wide and 200mm high. The calorimeter is calibrated by the dummy cell which generates the heat rate from zero to 200W. The measuring accuracy of the calorimeter is within $2\%$ and its voltage stability is 2.5mV in the constant temperature bath.

A Study on Design and Analysis of Module Control Method for Extended Use of Rechargeable Batteries in Mobile Devices (모바일 장치의 충전식 배터리 사용 연장을 위한 모듈 제어 방법 설계와 해석 연구)

  • Dohyeong Kim;jihoon Ryu;JinPyo Jo;JeongHo Kim
    • Journal of Platform Technology
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    • v.12 no.2
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    • pp.34-44
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    • 2024
  • This paper proposes a dynamic clock supply control algorithm and a system load power stabilization algorithm that minimizes the power consumption of the sensing system, which accounts for the largest percentage of power consumption in mobile devices, to extend the usage time of the rechargeable battery mounted on the mobile device. The dynamic clock supply control algorithm can reduce the power consumed by the sensing system by configuring a circuit to cut off the power of the sensing system and by recognizing the state of low sensor change and adjusting the measurement cycle. The system load power stabilization algorithm is an algorithm that controls the power of the surrounding module according to the power consumption state, and when it requires a lot of power, it controls the clock supply to stabilize the operation. The experimental results confirmed that applying only the dynamic clock supply control algorithm reduces the power consumed by the sensing system by 17%, and applying only the system load power stabilization algorithm reduces power consumption by 9.3%, enabling it to operate stably in situations that require a lot of power such as image processing. When both algorithms were applied, the power consumption of the battery was reduced by 67% compared to before applying the algorithm. Through this, the reliability of the proposed method was confirmed.

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A Study on the Present E-mail Marketing Status and Its Effective Utilization Methods on Local Internet Shopping Malls (국내(國內) 인터넷 패션 쇼핑몰의 E-mail 마케팅 현황(現況)과 효율적(效率的) 활용방안(活用方案)에 관(關)한 연구(硏究))

  • Jung, Yun-Kyoung;Kim, Il
    • Journal of Fashion Business
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    • v.7 no.1
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    • pp.38-54
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    • 2003
  • This study looked into the present status of e-mail marketing, which is conducted in local Internet fashion shopping malls and is being used as a one-to-one marketing method in the e-CRM concept so as to establish an effective e-mail marketing policy by grasping problems based on the current status and by presenting solutions to the problems. This study analyzed the e-mail letters received during a certain period of time by 30 professional Internet fashion shopping malls of with famous goods, brands and non-brands. Four individuals subscribed to shopping mall through the procedure for membership applying for e-mail services. The analysis showed that there were no shopping malls that were doing a differentiated e-mail marketing among Internet shopping malls. As for time factor, they were sending e-mail letters irregularly regardless of a certain cycle. And as for visual factor, they didnt have any standard for the content of the mail. As for content factor, the contents of their mail were not differentiated and all the same. The comparison of fashion malls showed that the brand shopping malls were the most active in e-mail marketing. On the basis of the problems, the direction for the effective e-mail marketing of Internet shopping malls are presented as follows: First, individualized contents fitting for customers should be developed, and differentiated mailing services should be provided thereby. Second, each shopping mall should make periodic tests of mailing to find out the optimal time and day to provide e-mail services to the customers at the designated time. Third, e-mail should be differentiated fitting for the website according to a certain on a certain standard for visual effects and the identity of shopping mall should be established. Firth, in the contents of e-mail, the image and message elements should be properly harmonized and creative policies should be made with interactive or recreational elements. Fifth, a homepage policy which can satisfy customers demand for information when the e-mail is clicked on..

Complexity Metrics for Analysis Classes in the Unified Software Development Process (Unified Process의 분석 클래스에 대한 복잡도 척도)

  • 김유경;박재년
    • The KIPS Transactions:PartD
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    • v.8D no.1
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    • pp.71-80
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    • 2001
  • Object-Oriented (OO) methodology to use the concept like encapsulation, inheritance, polymorphism, and message passing demands metrics that are different from structured methodology. There are many studies for OO software metrics such as program complexity or design metrics. But the metrics for the analysis class need to decrease the complexity in the analysis phase so that greatly reduce the effort and the cost of system development. In this paper, we propose new metrics to measure the complexity of analysis classes which draw out in the analysis phase based on Unified Process. By the collaboration complexity, is denoted by CC, we mean the maximum number of the collaborations can be achieved with each of the collaborator and detennine the potential complexity. And the interface complexity, is denoted by IC, shows the difficulty related to understand the interface of collaborators each other. We prove mathematically that the suggested metrics satisfy OO characteristics such as class size and inheritance. And we verify it theoretically for Weyuker' s nine properties. Moreover, we show the computation results for analysis classes of the system which automatically respond to questions of the it's user using the text mining technique. As we compared CC and IC to CBO and WMC, the complexity can be represented by CC and IC more than CBO and WMC. We expect to develop the cost-effective OO software by reviewing the complexity of analysis classes in the first stage of SDLC (Software Development Life Cycle).

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