• Title/Summary/Keyword: Interim analysis

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A Study on the Error Analysis and Performance Improvement of Low-Cost Inertial Sensors (저급 관성센서의 오차 분석 및 성능 향상에 관한 연구)

  • 박문수;원종훈;홍석교;이자성
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.28-28
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    • 2000
  • Low-cost solid-state inertial sensors of three rate Gyroscopes and a triaxial Accelerometer are evaluated in static and dynamic environments. As a interim result, error models of each inertial sensors are generated. Model parameters with respect to temperature are acquired in static environment. These error models are included in an Extended Kalman Filter(EKF) to compensate bias error due to temperature variation. Experimental results in dynamic environment are included to show the validity of the each error model and the performance improvement of a compensated low cost inertial sensors for a navigational application

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A Study on Customer Segmentation for CRM Analysis (CRM 분석을 위한 고객 세분화에 관한 연구)

  • 송관배;양광모;강경식
    • Journal of the Korea Safety Management & Science
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    • v.5 no.3
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    • pp.133-143
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    • 2003
  • Even in the present situation where any general criterion on CRM dose not exist, utilization of CRM is expected to be actively continued, which will cause many problems. In this regard, evaluating CRM counts. As the result, projects are being suspended and budgets cut, plans for introducing CRM suspended or cancelled and many CRM software vendors and technical consulting firms are facing serious management crisis. Yet, this phenomenon can be regarded as an interim one. In fact, some cases that successfully introduced CRM show that CRM is migrating from small scale which is typical when introduced to larger scale through various tests. Therefore, this study tries to segment customer for the sloving the problem. And it make efficient customer management. Using this model, SN ratio of taguchi method for each of subjective factors as well as values of weights are used in this comprehensive method for customer. A example is presented to illustrate the model and to show a rank reversal when compared to a model that does not eliminate extreme values and eliminates the highest and lowest experts' values allocating the weights and the subjective factors.

Aerodynamic and Structural Design on Small Wind Turbine Blade Using High Performance Configuration and E-Glass/Epoxy-Urethane Foam Sandwich Composite Structure

  • Kong, Changduk;Bang, Johyuk
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.401-407
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    • 2004
  • This study proposes a interim development result for the l-㎾ class small wind turbine system, which is applicable to relatively low wind speed regions like Korea and has the variable pitch control mechanism. In the aerodynamic design of the wind turbine blade, parametric studies were carried out to determine an optimum aerodynamic configuration which is not only more efficient at low wind speed but whose diameter is not much larger than similar class other blades. A light composite structure, which can endure effectively various loads, was newly designed. In order to evaluate the structural design of the composite blade, the structural analysis was performed by the finite element method. Moreover both structural safety and stability were verified through the full-scale structural test.

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Fault Tree Analysis for Risk Assessment of CO2 Leakage from Geologic Storage (지중 저장 이산화탄소의 누출 위험도 평가를 위한 결함수 분석)

  • Lee, Sang Il;Lee, Sang Ki;Hwang, Jin Hwan
    • Journal of Environmental Impact Assessment
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    • v.18 no.6
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    • pp.359-366
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    • 2009
  • CCS (Carbon Capture and Storage) is considered as the most promising interim solution to deal with the greenhouse gas such as $CO_2$ responsible for global warming. Even though carefully chosen geologic formations are known to contain stored gas for a long time period, there are potential risks of leakage. Up to now, applicable risk assessment procedures for the leakage of $CO_2$ are not available. This study presents a basis for risk analysis applicable to a complex geologic storage system. It starts with the classification of potential leakage pathways. Receptors and the leakage effect on them are identified and quantified. Then, a fault tree is constructed, which yields the minimum cut set (i.e., the most vulnerable leakage pathway) and quantifies the probability of the leakage risk through the cut set. The methodology will provide a tool for risk assessment in a CCS project. The outcomes of the assessment will not only ensure the safety of the CCS system but also offer a reliable and efficient monitoring plan.

Development of the Numerical Guide for Cost-Benefit Analysis of Occupational Radiation Exposure In the Korean Next Generation Reactor

  • Sohn, Ki-Yoon;Kang, Chang-Sun
    • Nuclear Engineering and Technology
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    • v.29 no.1
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    • pp.78-84
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    • 1997
  • The specific purpose of this study is to develop the numerical guide for the cost-benefit analysis of ORE ($/person-Sv reduction) to meet the criterion of ALARA in the design stage of the KNGR. In deriving the guide, the risk factor which is defined by the risk to unit collective radiation exposure dose (deaths/person-Sv) and the monetary value of human life ($/death) are required. The risk factor has been estimated from various clinical data accumulated for a number of years and continuously modified. And the monetary value of human life is usually quantified using the human capital approach. In this study, the risk to radiation exposure perceived by a group of people is investigated through an extensive poll survey conducted among university students in order to modify the existing risk factor for radiation exposure. And in evaluating the monetary value of human life, the QOL factor is introduced in order to incorporate the degree of public welfare or quality of life. As a result of study, a value within the range of 151, 000~172, 000 dollars per person-Sv reduction is recommended as the appropriate interim numerical guide for cost-benefit analysis of ORE to meet the criterion of ALARA in the design stage of the KNGR. A poll survey was also conducted in order to see whether the public acceptance cost of nuclear power should be incorporated in developing the guide, and the result of study shooed that such a cost does not need to be considered.

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IMPACT ANALYSES AND TESTS OF CONCRETE OVERPACKS OF SPENT NUCLEAR FUEL STORAGE CASKS

  • Lee, Sanghoon;Cho, Sang-Soon;Jeon, Je-Eon;Kim, Ki-Young;Seo, Ki-Seog
    • Nuclear Engineering and Technology
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    • v.46 no.1
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    • pp.73-80
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    • 2014
  • A concrete cask is an option for spent nuclear fuel interim storage. A concrete cask usually consists of a metallic canister which confines the spent nuclear fuel assemblies and a concrete overpack. When the overpack undergoes a missile impact, which might be caused by a tornado or an aircraft crash, it should sustain an acceptable level of structural integrity so that its radiation shielding capability and the retrievability of the canister are maintained. A missile impact against a concrete overpack produces two damage modes, local damage and global damage. In conventional approaches [1], those two damage modes are decoupled and evaluated separately. The local damage of concrete is usually evaluated by empirical formulas, while the global damage is evaluated by finite element analysis. However, this decoupled approach may lead to a very conservative estimation of both damages. In this research, finite element analysis with material failure models and element erosion is applied to the evaluation of local and global damage of concrete overpacks under high speed missile impacts. Two types of concrete overpacks with different configurations are considered. The numerical simulation results are compared with test results, and it is shown that the finite element analysis predicts both local and global damage qualitatively well, but the quantitative accuracy of the results are highly dependent on the fine-tuning of material and failure parameters.

Tolerability, Safety and Effectiveness of Paliperidone ER in Patients with Schizophrenia : A 24-Week Interim Analysis of the 48-Week Open-Label, Prospective, Switch Study (조현병 환자에서 Paliperidone Extended Release의 효능, 안전성 및 내약성 : 48주 개방형, 전향적 연구의 24주 중간 분석)

  • Choi, You Ra;Jung, Dong Chung;Kim, Eun Young;Kim, Se Hyun;Lee, Hyun Jeong;Lee, Nam Young;Chang, Sung Man;Shim, Joo Cheol;Joo, Eun Jeong;Kim, Jae Jin;Lee, Sang Hyuk;Chung, Young Chul;Kim, Yong Sik;Ahn, Yong Min
    • Korean Journal of Biological Psychiatry
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    • v.20 no.1
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    • pp.12-20
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    • 2013
  • Objectives We investigated the tolerability, safety, and treatment response to flexible-dose paliperidone ER in patients with non-acute schizophrenia in whom previous antipsychotic drugs were ineffective. Methods This 24-week interim analysis of the 48-week multicenter, prospective, open-label study assessed effectiveness using the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Schizophrenia-Severity (CGI-SCH-S) Scale, Personal and Social Performance (PSP) and Drug Attitude Inventory (DAI). Safety and tolerability were assessed using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) and Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS). Results Effectiveness was assessed in 169 patients. Significant improvement in the PANSS total score was observed by week-1 and continued until week-24. The response rate was 33%. The CGI-SCH-S and PSP total scores significantly improved during 24 weeks ; however, no change occurred in the total DAI. Fifty-nine percent of patients reported adverse events, of which extrapyramidal symptoms were the most frequent (19.0%). The DIEPSS and LUNSERS scores were improved after 24 week. Conclusions Switching to the flexible-dose paliperidone ER from an ineffective antipsychotic drug was safe, tolerable, and showed a good treatment response in Korean patients with schizophrenia.

Development of Spent Nuclear Fuel Transportation Worker Exposure Scenario by Dry Storage Methods (건식 저장방식별 사용후핵연료 운반 작업자 피폭시나리오 개발)

  • Geon Woo Son;Hyeok Jae Kim;Shin Dong Lee;Min Woo Kwak;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.18 no.1
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    • pp.43-52
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    • 2024
  • Currently, there are no interim storage facilities and permanent disposal facilities in Korea, so all spent nuclear fuels are temporarily stored. However, the temporary storage facility is approaching saturation, and as a measure to this, the 2nd Basic Plan for the Management of High-Level Radioactive Waste presented an operation plan for dry interim storage facilities and dry temporary storage facilities on the NPP on-site. The dry storage can be operated in various ways, and to select the optimal dry storage method, the reduction of exposure for workers must be considered. Accordingly, it is necessary to develop a worker exposure scenario according to the dry storage method and evaluate and compare the radiological impact for each method. The purpose of this study is to develop an exposure scenario for workers transporting spent nuclear fuel by dry storage method. To this end, first, the operation procedure of the foreign commercial spent nuclear fuel dry storage system was analyzed based on the Final Safety Analysis Report (FSAR). 1) the concrete overpack-based system, 2) the metal overpack-based system, and 3) the vertical storage module-based system were selected for analysis. Factors were assumed that could affect the type of work (working distance, working hours, number of workers, etc.) during transportation work. Finally, the work type of the processes involved in transporting spent nuclear fuel by dry storage method was set, and an exposure scenario was developed accordingly. The concrete overpack method, the metal overpack method, and the vertical storage module method were classified into a total of 31, 9, and 23 processes, respectively. The work distance, work time, and number of workers for each process were set. The product of working hours and number of workers (Man-hour) was set high in the order of concrete overpack method, vertical storage module method, and metal overpack method, and short-range work (10 cm) was most often applied to the concrete overpack method. The results of this study are expected to be used as basic data for performing radiological comparisons of transport workers by dry storage method of spent nuclear fuel.

Finite Element Analysis and Development of Interim Consolidated 5-N Curve for Fatigue Design of Welded Structure (용접구조물의 피로설계를 위한 유한요소 해석 및 통합 피로선도 초안 개발)

  • Kim, Jong-Sung;Jin, Tae-Eun;Hong, Jeong-Kyun;P. Dong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.5
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    • pp.724-733
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    • 2003
  • Fatigue design rules for welds in the ASME Boiler and Pressure Vessels Code are based on the use of Fatigue Strength Reduction Factors(FSRF) against a code specified fatigue design curve generated from smooth base metal specimens without the presence of welds. Similarly, stress intensification factors that are used in the ASME B3l.1 Piping Code are based on component S-N curves with a reference fatigue strength based on straight pipe girth welds. But the determination of either the FSRF or stress intensification factor requires extensive fatigue testing to take into account the stress concentration effects associated with various types of component geometry, weld configuration and loading conditions. As the fatigue behavior of welded joints is being better understood, it has been generally accepted that the difference in fatigue lives from one type of weld to another is dominated by the difference in stress concentration. However, general finite element procedures are currently not available for effective determination of such stress concentration effects. In this paper, a mesh-insensitive structural stress method is used to re-evaluate the S-N test data, and then more effective method is proposed for pressure vessel and piping fatigue design.

Performance Analysis on Income Generation Works in Comprehensive Rural Village Development Project by Their Implementation (농촌마을종합개발사업의 공동소득사업 성과분석)

  • Yang, Won-Sik;Choi, Soo-Myung
    • Journal of Korean Society of Rural Planning
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    • v.19 no.1
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    • pp.55-70
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    • 2013
  • Since 2004, Ministry for Food, Agriculture, Forestry and Fisheries(MIFAFF) has been carrying out comprehensive rural village development project as the core one of Rural Area Development Schemes in Korea. Up to now, 56 projects had been completed after having with 5-year plan implementation period, on which it is possible to try post-project evaluation works. This study aims to propose a rational income-generation works model of comprehensive rural village development project, based on fulfillment checking results of their statutory stepwise working procedures specified in the project guidelines and their interim/post project performance analysis results in 56 project areas above mentioned. In comprehensive rural village development project, income-generation works generally have both quantitative and qualitative effects to rural communities; the former is focussed on income increasement of villagers, while the latter on community revitalization through job creation and spill-over effects of other linked community activities. So, the research works of this study focussed on these two comprehensive effects above mentioned.