• Title/Summary/Keyword: evaluation studies

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MAINTENANCE PERFORMANCE EVALUATION OF THE BUILDINGS IN THE DESIGN PHASE

  • Hakyu Baeck;Chansik Lee
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.1138-1143
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    • 2005
  • As the importance of building maintenance is being emphasized, studies regarding the efficient building maintenance focus on the evaluation of the maintenance plan, implementation and its cost only while the evaluation of the maintenance performance is nearly ignored. At this point when the importance is placed on the performance design we need to have methods to improve maintenance performance of the buildings in Design Phase. The purpose of this study was to set the design evaluation items to improve the maintenance performance of the buildings. Through the review of the existing literature, we set the concept of the maintenance performance and suggested evaluation items to evaluate the maintenance performance through the analysis of domestic and overseas certification and design guidelines.

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Evaluation Factors of PDM Systems (PDM 시스템의 평가에 관한 연구)

  • 강석호;김영호;황영헌;김대환
    • The Journal of Society for e-Business Studies
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    • v.1 no.1
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    • pp.209-226
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    • 1996
  • System Intergration (SI) has resently been conceived as one df the most important tools for enforciong and reinforcing the competitiveness of an enterprise. A major concern of SI lies in sharing many types of information, such as engineering, production, finance, marketing, and so on. Product Data Management (PDM) systems are mainly concerned with product- related information, and also support a large portion of the Commerce At Light Speed (CALS) straitegy. PDM systems receive a great amount df attention form industry, A variety of PDM solutions have been introduced for the last few years, and its market has expanded very fast with an annual growth of 30%. However, in general, it is not an easy task to choose a right PDM solution for a particular company. A major purpose of this paper is to provide essential factors in evaluating PDM systems. While developing the factors. we consider the expected future trend of PDM technologies and three types of PDM-based intergration (frontward, rearward, and sideward integrations). We Propose to carry out the evaluation process in two fold. An overall evaluation is performed first to narrow down many alternatives into a few candidate systems, and then a detailed technical evaluation step follows to determine the final solution. A number of influencing factors are categorized and described in each of these steps.

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Structural identification based on incomplete measurements with iterative Kalman filter

  • Ding, Yong;Guo, Lina
    • Structural Engineering and Mechanics
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    • v.59 no.6
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    • pp.1037-1054
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    • 2016
  • Structural parameter evaluation and external force estimation are two important parts of structural health monitoring. But the structural parameter identification with limited input information is still a challenging problem. A new simultaneous identification method in time domain is proposed in this study to identify the structural parameters and evaluate the external force. Each sampling point in the time history of external force is taken as the unknowns in force evaluation. To reduce the number of unknowns for force evaluation the time domain measurements are divided into several windows. In each time window the structural excitation is decomposed by orthogonal polynomials. The time-variant excitation can be represented approximately by the linear combination of these orthogonal bases. Structural parameters and the coefficients of decomposition are added to the state variable to be identified. The extended Kalman filter (EKF) is augmented and selected as the mathematical tool for the implementation of state variable evaluation. The proposed method is validated numerically with simulation studies of a time-invariant linear structure, a hysteretic nonlinear structure and a time-variant linear shear frame, respectively. Results from the simulation studies indicate that the proposed method is capable of identifying the dynamic load and structural parameters fairly accurately. This method could also identify the time-variant and nonlinear structural parameter even with contaminated incomplete measurement.

Development of Evaluation Metrics for Pedestrian Flow Optimization in a Complex Service Environment Based on Behavior Observation Method

  • Bahn, Sang-Woo;Lee, Chai-Woo;Kwon, Sang-Hyun;Yun, Myung-Hwan
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.4
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    • pp.647-654
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    • 2010
  • In a service environment, the spatial layout is an important factor that has a great impact on customers' behavioral characteristics including wayfinding and purchasing. Previous studies have shown a gap between marketing, focusing solely on profitability and satisfaction, and architecture, looking only into efficiency of pedestrian flow. To balance such disparity, this study suggests an integrated approach for assessing behavioral patterns in complex service environments. With the objective that complex service environments should aim to increase its profitability and efficiency while guaranteeing customer satisfaction, quantitative metrics was developed for evaluation. The metrics was defined to use data from behavior observation including path tracking, population counting, and gaze analysis, while previous studies have relied on abstract survey methods that were prone to sampling errors and loss of data. For validation of the metrics in a real world setting, a case study was conducted at 4 train stations in Korea. In the case study, experiments were conducted to gather the required data in all 4 train stations, while their physical layouts were also analyzed. With the results from the case study, comparative evaluation of the 4 train stations in terms of behavioral efficiency was possible, together with a discussion on the effect of their physical settings.

Performance Evaluation of an Oxy-coal-fired Power Generation System - Thermodynamic Evaluation of Power Cycle (순산소 석탄 연소 발전 시스템의 성능 평가 - 동력 사이클의 열역학적 해석)

  • Lee, Kwang-Jin;Choi, Sang-Min;Kim, Tae-Hyung;Seo, Sang-Il
    • Journal of the Korean Society of Combustion
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    • v.15 no.2
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    • pp.1-11
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    • 2010
  • Power generation systems based on the oxy-coal combustion with carbon dioxide capture and storage (CCS) capability are being proposed and discussed lately. Although a large number of lab scale studies for oxy-coal power plant have been made, studies of pilot scale or commercial scale power plant are not enough. Only a few demonstration projects for oxy-coal power plant are publicized recently. The proposed systems are evolving and various alternatives are to be comparatively evaluated. This paper presents a proposed approach for performance evaluation of a commercial 100 MWe class power plant, which is currently being considered for 'retrofitting' for the demonstration of the concept. The system is configurated based on design and operating conditions with proper assumptions. System components to be included in the discussion are listed. Evaluation criteria in terms of performance are summarized based on the system heat and mass balance and simple performance parameters, such as the fuel to power efficiency and brief introduction of the second law analysis. Also, gas composition is identified for additional analysis to impurities in the system including the purity of oxygen and unwanted gaseous components of nitrogen, argon and oxygen in air separation unit and $CO_2$ processing unit.

Integrity Evaluation of Deep Foundations by Using Impact Echo Method(Numerical Study) (충격반향기법을 이용한 깊은 기초의 건전도 평가(수치해석))

  • 김동수;박연홍
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.139-152
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    • 1999
  • These days we broadly apply drilled shafts for deep foundations to build infrastructures. The defects of the deep foundations cause the decrease of their support load capacity and the increase of settlement, and the subsequent damage of the super-structures. In consequence, non-destructive testings techniques of concrete piles are important for their integrity evaluation. To improve understanding and reliable application of the impact echo method for the integrity evaluation of the drilled concrete piles, numerical studies of the impact response of concrete piles by using axi-symmetric three-dimensional finite element method are peformed for (a) sound piles: (b) piles containing necks, voids and layers of low-quality concrete: and (c) piles in soil and/or above rock. The results of these studies show that the finite element method is effective for evaluating the impact response of drilled concrete piles.

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Probabilistic Reliability Analysis of KEPCO System Using TRELSS

  • Tran Trung Tinh;Kwon Jung-Ji;Choi Jae-Seok;Choo Jin-Boo;Jeon Dong-Hun;Han Kyoeng-Nam;Billinton Roy
    • Journal of Electrical Engineering and Technology
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    • v.2 no.1
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    • pp.10-18
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    • 2007
  • The importance of conducting necessary studies on grid reliability evaluation has become increasingly important in recent years due to the number of blackout events occurring throughout the world. Additionally, quantitative evaluation of transmission system reliability is very important in a competitive electricity environment. The reason behind this is that successful operation of an electric power company under a deregulated electricity market depends on transmission system reliability management. The results of many case studies for the Korea Electric Power Cooperation (KEPCO) system using the Transmission Reliability Evaluation for Large-Scale Systems (TRELSS) Version 6.2 are illustrated in this paper. The TRELSS was developed by EPRI and Southern Company Services Inc. This paper presents the reliability analysis of KEPCO system expansion planning by using the TRELSS program.

Evaluation of English speaking proficiency under fixed speech rate: Focusing on utterances produced by Korean child learners of English

  • Narah Choi;Tae-Yeoub Jang
    • Phonetics and Speech Sciences
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    • v.15 no.1
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    • pp.47-54
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    • 2023
  • This study attempted to test the hypothesis that Korean evaluators can score L2 speech appropriately, even when speech rate features are unavailable. Two perception experiments-preliminary and main-were conducted sequentially. The purpose of the preliminary experiment was to categorize English-as-a-foreign-language (EFL) speakers into two groups-advanced learners and lower-level learners-based on the proficiency scores given by five human raters. In the main experiment, a set of stimuli was prepared such that the speech rate of all data tokens was modified to have a uniform speech rate. Ten human evaluators were asked to score the stimulus tokens on a 5-point scale. These scores were statistically analyzed to determine whether there was a significant difference in utterance production between the two groups. The results of the preliminary experiment confirm that higher-proficiency learners speak faster than lower-proficiency learners. The results of the main experiment indicate that under controlled speech-rate conditions, human raters can appropriately assess learner proficiency, probably thanks to the linguistic features that the raters considered during the evaluation process.

Traumatic Brachial Plexus Injury: Preoperative Evaluation and Treatment Principles (상완 신경총 손상에서의 수술 전 평가와 치료 계획)

  • Yoo, Jae-Sung;Park, Sung-Bae;Kim, Jong-Phil
    • Archives of Hand and Microsurgery
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    • v.22 no.3
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    • pp.137-146
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    • 2017
  • Brachial plexus injury is regarded as one of the most devastating injuries of the upper extremity. Accurate diagnosis is important to obtain the successful results. Basic preoperative evaluation includes simple radiography, cervical myelography. Magnetic resonance imaging, angiography, electrophysiologic studies and intraoperative studies. Furthermore, proper timing of surgery, surgical indication, plan and sufficient understanding of patients about the prognosis are the key for the satisfactory outcomes. This article provides an overview of the evaluation, diagnosis, intraoperative monitoring, and proper surgical planning for the treatment of posttraumatic brachial plexus injuries.

Toxicity Assessment of Cyperi rhizoma Aqueous Extract Orally Administered to Rats for 13 Consecutive Weeks (랫드에서 향부자 추출물의 13주 반복 경구투여 독성평가)

  • Han, So-Ri;Han, Hyoung-Yun;Park, Heejin;Mi, Byung-Sun;Chung, Moon-Koo;Moon, Kyoung-Sik;Jeong, Ja Young;Roh, Hang-Sik;Seok, Ji Hyeon;Kim, Sang Kyum
    • YAKHAK HOEJI
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    • v.57 no.4
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    • pp.258-264
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    • 2013
  • Herbal medicine has been traditionally used in Asian countries for a long time. Many pharmacological effects are identified in the herbs and these herbs are believed to be safe for human. However, the safety or adverse effect of some traditional herbal medicines has not been established. We have chosen Cyperi rhizoma based on the Korea Herbal Pharmacopoeia and which have been widely used for an anti-inflammatory effect in Korea. The object of the study was to evaluate safety of Cyperi rhizoma in rats. The aqueous extract of Cyperi rhizoma was prepared according to the standard hot water extraction method of the Korea Pharmacopoeia. In the sub-chronic study, the aqueous extract of Cyperi rhizoma was orally administered once daily as 0, 125, 250, 500, 1000 and 2000 mg/kg/day to male and female F344 rats for 13 weeks. There were no treatment related abnormalities in mortality, clinical signs, food consumption, ophthalmologic examination, hematology, serum chemistry, urinalysis, gross observation, organ weight and histopathologic examination. In conclusion, The NOAEL (No Observed Adverse Effect Level) for Cyperi rhizoma aqueous extract was determined as more than 2000 mg/kg/day in the present experimental condition.