• Title/Summary/Keyword: Transfer effectiveness

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NUMERICAL STUDY FOR THE FULL-SCALE ANALYSIS OF PLATE-TYPE HEAT EXCHANGER USING ONE-DIMENSIONAL FLOW NETWORK MODEL and ε-NTU METHOD (판형 열교환기 Full-scale 해석을 위한 1차원 유동 네트워크 모델 및 ε-NTU 모델의 수치적 연구)

  • Kim, Minsung;Min, June Kee;Ha, Man Yeong
    • Journal of computational fluids engineering
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    • v.19 no.1
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    • pp.47-56
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    • 2014
  • Since a typical plate heat exchanger is made up of a huge number of unitary cells, it may be impossible to predict the aero-thermal performance of the full scale heat exchanger through three-dimensional numerical simulation due to the enormous amount of computing resources and time required. In the present study, a simple flow-network model using the friction factor correlation and a thermal-network model based on the effectiveness-number of transfer units (${\varepsilon}$-NTU) method has been developed. The complicated flow pattern inside the cross-corrugated heat exchanger has been modeled into flow and thermal networks. Using this model, the heat transfer between neighboring streams can be considered, and the pressure drop and the heat transfer rate of full-scale heat exchanger matrix are calculated. In the calculation, the aero-thermal performance of each unitary cell of the heat exchanger matrix was evaluated using correlations of the Fanning friction factor f and the Nusselt number Nu, which were calculated by unitary-cell CFD model.

Layout Criteria of an Access Mode's on and off Facility at Multiple Transfer Centers (복합환승센터 접근교통수단의 승하차 시설배치기준)

  • Kim, Si-Gon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.2D
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    • pp.95-101
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    • 2012
  • Layout Criteria are developed for an access mode's on and off facility at multiple transfer centers in this paper. Layout Criteria are location issues between a main mode and access modes in terms of the on and off facility one another. The total distance between them has been suggested to be minimized. In the distance calculation stairs are considered to be more difficult and than open space. On the other hand an escalator and an elevator are treated as easier than open space. Considering the number of people between on and off facility, the weighted average distance is suggested to be a MOE(Measure of effectiveness) for layout criteria at multiple transfer centers. Finally, the layout criteria are applied to the existing Kimpo airport terminal and some improvement ideas are suggested.

A Feature-Based Malicious Executable Detection Approach Using Transfer Learning

  • Zhang, Yue;Yang, Hyun-Ho;Gao, Ning
    • Journal of Internet Computing and Services
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    • v.21 no.5
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    • pp.57-65
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    • 2020
  • At present, the existing virus recognition systems usually use signature approach to detect malicious executable files, but these methods often fail to detect new and invisible malware. At the same time, some methods try to use more general features to detect malware, and achieve some success. Moreover, machine learning-based approaches are applied to detect malware, which depend on features extracted from malicious codes. However, the different distribution of features oftraining and testing datasets also impacts the effectiveness of the detection models. And the generation oflabeled datasets need to spend a significant amount time, which degrades the performance of the learning method. In this paper, we use transfer learning to detect new and previously unseen malware. We first extract the features of Portable Executable (PE) files, then combine transfer learning training model with KNN approachto detect the new and unseen malware. We also evaluate the detection performance of a classifier in terms of precision, recall, F1, and so on. The experimental results demonstrate that proposed method with high detection rates andcan be anticipated to carry out as well in the real-world environment.

MODELING THE TECHNOLOGY TRANSFER PROCESS IN THE THAI CONSTRUCTION INDUSTRY: A PILOT STUDY

  • Tanut Waroonkun;Rodney A. Stewart;Sherif Mohamed
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.845-848
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    • 2005
  • Technology transfer (TT) has been defined as the shared responsibility between the source and the destination for ensuring that technology is accepted and at least understood by someone with the knowledge and resources to apply and/or use the technology. The adoption of TT in construction industries is necessary for economic growth to occur in developing countries such as Thailand. This process should provide numerous benefits for the host sector in areas such as increased productivity, enhancement of product quality, cost savings, improvements in market share and entry to new markets. However, there are many factors, which may impact on the TT process and its subsequent outcomes for Thai construction firms and individuals, including, the transfer environment, learning environment, transferor characteristics and transferee characteristics. The performance and interaction of these enablers will influence the degree of value added to the local construction sectors in areas such as economic advancement, knowledge advancement and project performance. This paper presents a conceptual framework for international TT that accommodates the numerous factors believed to impact on the processes effectiveness. Through a Pilot Study, where 27 industry professionals from Thailand were interviewed, the significant factors which impact on the TT process have been identified along with the strength of interrelationship between individual and groups of factors. Future research seeks to target a greater sample of respondents with the view to validate the conceptual model and apply it on a number of large Thai projects where international TT was incorporated into the project agreement.

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A TQM case of Centralized Sequential Decision-making Problem

  • Chang, Cheng-Chang;Chu, Yun-Feng
    • International Journal of Quality Innovation
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    • v.4 no.1
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    • pp.131-147
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    • 2003
  • This paper considers that a public department under specialized TQM manpower constraints have to implement multiple total quality management (TQM) policies to promote its service performance (fundamental goal) by adopting a centralized sequential advancement strategy (CSAS). Under CSAS, the decision-makers (DMs) start off by focusing specialized TQM manpower on a single policy, then transfer the specialized TQM manpower to the next policy when the first policy reaches the predetermined implementation time limit (in terms of education and training). Suppose that each TQM policy has a different desirous education and training goal. When the desirous goals for all TQM policies are achieved, we say that the fundamental goal will be satisfied. Within the limitation of total implementation period of time for all policies, assume the desirous goals for all TQM policies cannot be achieved completely. Under this premise, the optimal implementation sequence for all TQM policies must be calculated to maximize the weighted achievement of the desirous goal. We call this optimization problem a TQM case of "centralized sequential decision-making problem (CSDMP)". The achievement of the desirous goal for each TQM policy is usually affected by the experience in prior implemented policies, which makes solving CSDMP quite difficult. As a result, this paper introduces the concepts of sequential effectiveness and path effectiveness. The structural properties are then studied to propose theoretical methods for solving CSDMP. Finally, a numerical example is proposed to demonstrate CSDMP′s usability.

Thermal Characteristics of Cross-flow Small Scale Heat Exchanger (소형 직교류 열교환기의 열적 특성에 관한 연구)

  • Kum, Sungmin;Yu, Byeonghun;Rhee, Kwan-Seok;Lee, Seungro
    • Journal of Energy Engineering
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    • v.22 no.1
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    • pp.44-50
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    • 2013
  • This study was experimentally investigated NOx and CO emissions characteristics with various equivalence ratios using premixed type of burner installed small heat exchanger. The effectiveness of heat exchanger and the entropy generation number were also calculated. As results, the heat transfer rate increases with increasing equivalence ratio due to increase the flame temperature. According to the emission characteristics and the effectiveness, the optimal operating equivalence ratio is 0.75 in the range of this experiment. Consequently, the area of the heat exchanger should be increased to reduce the entropy generation number and to increase the effectiveness.

A study on the effectiveness of core competency courses according to facilitating strategy of learning transfer focusing H Corporation (학습전이 촉진 전략에 따른 핵심역량교육의 효과성 연구 -H사 사례를 중심으로-)

  • Kim, Young-Kil
    • Journal of Digital Convergence
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    • v.12 no.8
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    • pp.175-186
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    • 2014
  • The purpose of this study is to demonstrate the effectiveness of core competency courses by scrutinizing H Corporation case. The primary data survey was taken from direct and indirect participants of H Corporation core competency courses. The findings from the study are as follow. Firstly, before-and-after average differences were significant in inspecting core competency courses. Secondly, participants' own expected core competency was comparatively lower than how observers evaluated the participants. Thirdly, Core competency courses directly and indirectly influenced on the business performance. Therefore, the conclusions of the study are firstly, core competency courses may work effectively for the goal of the company in changing employees' organizational behavior. Secondly, for the better result of the core competency courses, customized and integrated learning transfer model for the particular company should be designed from the beginning of the education.

A scheme of EEMR protocol for energy efficient in wireless sensor networks (EEMR 프로토콜을 이용한 무선 센서 네트워크 노드의 에너지 소비 절감 방법)

  • Cho, Ik-Lae;Lee, Ho-Sun;Lee, Kyoon-Ha
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.229-237
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    • 2005
  • One of the important issues of in this research is effective usage of energy to increase life time of nodes which form a network. Existing LEEM protocol causes unnecessary active time due to small packets with shorter transfer time than active interval period of node and packets with transfer time of more than twice of active interval period of node. In this paper, we propose Energy-Efficient MAC by Reservation (EEMR) protocol which can increase energy effectiveness in wireless sensor network environment by reducing unnecessary active time using a method that reserves next-hop depend upon the size of packet. We evaluated effectiveness of our proposed method through experiments. The result showed that using EEMR protocol had better energy effectiveness than existing LEEM protocol by 15%.

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Development of Bioreactors for Hydrogen-Producing Immobilized Photosynthetic Bacteria(II) : Evaluation of Immobilized Bioreactor for Hydrogen Productivity and Mass Transfer Resistance (광합성 박테리아를 이용한 고성능 수소 생산 고정화 생물반응기의 개발(II) :고정층 반응기와 연속 교반탱크 반응기에서의 수소 생산성 및 물질전달 저항 비교)

  • 선용호;한정우
    • KSBB Journal
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    • v.8 no.3
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    • pp.256-265
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    • 1993
  • In this study, it was observed that hydrogen productivity varied with changes of input g1ucose concentration and dilution rate in FBR( Fixed Bed Reactor), and CSTR(Continuous Stirred Tank Reactor). We evaluated and compared reaction rate Parameters and internal external and overall mass transfer resistances of immobilized carrier in both reactors. Apparent $K_m$ decreased with increasing dilution rate in FBR but showed a constant value above $0.4h^{-1}$ of dilution rate in CSTR. The experimental results in FBR showed nearly analogous to those in CSTR, however, the performance of FBR resulted in lower hydrogen productivity and an external effectiveness factor but a higher internal effectiveness factor than in CSTR. The overall effectiveness factor obtained with various input 91ucose concentrations showed similar values in both reactors.

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The Effectiveness of 448-kHz Capacitive Resistive Monopolar Radiofrequency for Subcutaneous Fat Reduction in a Porcine Model

  • Kwon, Tae-Rin;Lee, Sung-Eun;Kim, Jong Hwan;Jeon, Yong Jae;Jang, You Na;Yoo, Kwang Ho;Kim, Beom Joon
    • Medical Lasers
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    • v.8 no.2
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    • pp.64-73
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    • 2019
  • Background and Objectives The effectiveness of many physiotherapy modalities in reducing subcutaneous fat has been investigated in numerous previous studies. However, to the best of our knowledge, there have been no attempts to determine the effectiveness of physiotherapy modalities in body contouring. The present report determined the effect of 448-kHz capacitive resistive monopolar radiofrequency (CRMRF) in a porcine model. Materials and Methods This study investigated the effect of selective destruction of the subcutaneous fat layer in abdominal fat tissue using CRMRF. The effects of two types of CRMRF (capacitive electric transfer (CET) and resistive electric transfer (RET)) treatment were evaluated using regular digital photography in addition to thermal imaging evaluation, ultrasound measurement, hematological evaluation, and histologic analyses (H&E (hematoxylin and eosin), Oil red O, and immunohistochemistry staining). Results Preclinical evaluation was performed to obtain the data for comparison of the safety and efficacy of the subcutaneous fat reduction after applying CRMRF using CET and RET. After treatment, the thermal transmission was effective, and a 42-47℃ temperature change was observed in the fat layer while an approximately temperature of 42℃ was confirmed on the skin surface. Moreover, after the application of both types of CRMRF treatment, fibrotic septa were observed in the adipose tissue induced by heat at the treatment sites. TUNEL staining was also performed to confirm the process of apoptosis in the adipocytes. Conclusion These results suggest that both CET and RET for CRMRF treatment are safe and effective for subcutaneous fat reduction in a porcine model.