• Title/Summary/Keyword: Work capacity evaluation

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Capacity Evaluation of VoIP Service over HSDPA with Frame-Bundling (HSDPA 시스템에서 Frame-Bundling을 채용한 VoIP 서비스 용량 평가)

  • Hwang, Jong-Yoon;Kim, Yong-Seok;Whang, Keum-Chan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3B
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    • pp.161-167
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    • 2007
  • In this paper, we evaluate the capacity of voice over internet protocol (VoIP) services over high-speed downlink packet access (HSDPA), in which frame-bundling (FB) is incorporated to reduce the effect of relatively large headers in the IP/UDP/RTP layers. Also, a modified proportional pair (PF) packet scheduler design supporting for VoIP service is provided. The main focus of this work is the effect of FB on system outage based on delay budget in radio access networks. Simulation results show that VoIP system performance with FB scheme is highly sensitive to delay budget. We also conclude that HSDPA is attractive for transmission of VoIP if compared to the circuit switched (CS) voice that is used in WCDMA (Release'99).

Evaluation on the Deformation Capacity of Multipurpose Floor Level Joint System (다목적 바닥 레벨조인트의 변형 능력 평가)

  • Seo, Soo-Yeon;Choi, Yun-Cheul;Kang, In-Seok;Lee, Li-Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.197-204
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    • 2005
  • Multipurpose Floor Level Joint(MFLJ) is a new construction technology system which was developed in domestic. By using this system, it is possible not only to absorb the deformation at expansion joint due to shrinkages of concrete but also to make ease the floor leveling during the concrete casting at floor. The system consists of two elements, supporting devices and rails. Their structural capacities were verified through several experimental programs, such as compressive strength test of support and bending test of rail. The purpose of this paper is to evaluate the deformation absorbing capacity of the floor level joint. An experimental work was carried out to simulate the deformation condition at the joint and the test result was analyzed and evaluated. In addition, FEM analysis for expansion joint of typical building was also performed to predict the real behavior of MFLJ. The test results showed that MFLJ has sufficient deformation capacity required to act as expansion joint.

The Constructability Evaluation of Ecological Restoration Construction Using Environment-friendly Design Factor - In the case of Construction of Gucheon Eco-River in Geoge City - (친환경적 설계인자를 적용한 생태복원공사의 시공성 평가 - 거제시 구천천 생태하천 조성공사를 중심으로 -)

  • An, Byung-Chul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.4
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    • pp.99-114
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    • 2013
  • In this study, constructability of ecologocal stream restoration process was evaluated and improved approaches for habitat were suggested. The study site is Gucheon River in Geoje city where conducted ecologocal restoration work within maintaining its flood control function. Application of ecological design factors and constructability in the process from planning to construction was analyzed and its results are as follows: In the process of planning and designing, it was focused more on the naturality of Gucheon River rather than the human convinience and ecological design factors were applied within the ecological capacity of the site. First, the indexes for constructability evaluation is selected. It was classified into three major categories as construction quality, design quality and construction administration system. Each index has details, so there are twenty sub indexes for contractibility evaluation. Second, the evaluation results shows that the index most in need of improvement was plumbing construction, followed by Stone construction and pavement construction. design concept was evaluated as appropriate in entire categories. Finally it is suggested that it can be improved in both process of design to enhance the technology and process of construction to enhance the quality management. The constructability of ecological stream needs adaptive management and it must be discussed with its designing which is at the stage before construction. Also it needs discussion with its designer constantly and feed-back process.

Corrosion Evaluation for Advanced Fuel Cycle Facilities (선진 핵연료주기 시설(AFC)의 부식건전성 조사, 분석)

  • Hwang, Seong Sik
    • Corrosion Science and Technology
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    • v.11 no.6
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    • pp.213-217
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    • 2012
  • The amount of spent fuel from nuclear power plants has been increasing. An effective management plan of the spent fuel becomes a critical issue, because the storage capacity of each plant will reach its storage limit in a few years. The volume of high toxic spent fuel can be reduced through a fuel processing. Advanced Fuel Cycle (AFC) system is considered to be one of the options to reduce the toxicity and volume of the spent fuel. It is necessary to set up a test facility to demonstrate the feasibility of the process at the engineering scale. The objective of the work is a development of the safety evaluation technology for the AFC system. The evaluation technology of the AFC structural integrity and processes were surveyed and reviewed. Key evaluation parameters for the main processes such as electrolytic reduction, electrorefining, and electrowinning were obtained. The survey results may be used for the establishment of the AFC regulatory licensing procedure. The establishment of the licensing criteria minimizes the trials and errors of the AFC facility design. Issues taken from the survey on the regulatory procedure and design safety features for the AFC facility provide a chance to resolve potential issues in advance.

An Experimental Study on the Construction Performances and Economical Evaluation of the Self-compacting Concrete by Cementitious Materials (결합재에 따른 자기충전 콘크리트의 시공성 및 경제성 평가에 관한 실험적 연구)

  • Kwon, Yeong-Ho
    • Journal of the Korea Concrete Institute
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    • v.29 no.3
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    • pp.315-322
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    • 2017
  • The purpose of this study is to investigate experimentally the construction performances and economical evaluation of the self-compacting concrete in actual site work after selecting the optimum mix proportions according to cementitious materials. Slag cement type of 46.5% slag powder and belite cement of 51.4% $C_2S$ content, lime stone powder as binders are selected for site experiment including water cement ratio. Also, test items for optimum mix proportion are as followings ; (1) Slump flow, 500 mm reaching time, V-type flowing time and U-box height (2) Setting time, bleeding, shortening depth and adiabatic temperature rising (3) Mixing time in plant (4) Concrete quantity and cost, quality control in actual concrete work. As test results, (4) Optimum water-cement ratio ; Slag cement type 41.0% and belite cement 51.0% (2) Setting time and bleeding finishing time of slag cement are faster, bleeding content of slag cement is higher, shortening depth and adiabatic temperature rising of belite cement type are lower (3) Optimum mixing time in batcher plant is 75 seconds and concrete productive capacity is about $100{\sim}110m^3/hr$. (4) Belite cement type is lower than slag cement type in material cost 14.0%, and concrete quantity in actual concreting work save 3.3% in case of belite cement type. Therefore, self-compacting concrete of belite cement type is definitely superior to that of slag cement type in various test items without compressive strength development.

Structural Capacity Evaluation of System Scaffolding using X-Type Advanced Guardrail (교차가새형 선행 안전난간을 적용한 시스템비계의 구조 성능 평가)

  • Park, J.D.;Lee, H.S.;Shin, W.S.;Kwon, Y.J.;Park, S.E.;Yang, S.S.;Jung, K.
    • Journal of the Korean Society of Safety
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    • v.35 no.5
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    • pp.49-58
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    • 2020
  • In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

An Experimental Study on the Evaluation of Residual Tensile Load-carrying Capacity of Corroded Steel Plates of Temporary Structure (가시설 부식 강재의 잔존 인장 내하성능 평가에 관한 실험적 연구)

  • Kim, In-Tae;Chang, Hong-Ju;Cheung, Ji-Young
    • Journal of Korean Society of Steel Construction
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    • v.22 no.5
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    • pp.399-409
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    • 2010
  • Steel structures are threatened to reduce load-carrying capacity as the cross section is decreased by corrosion. However, there has been no method in definitely evaluating residual load-carrying capacity and the effect of corrosion to the load-carrying capacity of steel. This study evaluated tensile residual load-carrying capacity of corroded steel plates by using tensile tests of specimens, which were selected from the web of temporary structure's main beam. After the surface shapes were measured and tensile tests were examined, the rust of 21 corroded specimens was, first of all, removed using a chemical method. From the tensile test result, which of reference specimens that was picked off at the flange of the same main 13-mm-thick beam and corroded specimens were based, surface geometry and correlation with the reduction of corroded thickness and strain, yield strength or tensile strength was established as constant numbers. Effective thickness of corroded steel with irregular cross sections could be calculated using average residual thickness and standard deviation. The irregular cross sections could be the evaluated tensile strength that is equalized to non-corroded uniform steel's regardless of corrosion. Also, reasonable measuring intervals of residual thickness could be proposed by using this result to apply for executive work.

A Qualitative Study of Running질 Science Garden질 (과학동산 운영에 관한 질적 연구)

  • 채동현;이수영
    • Journal of Korean Elementary Science Education
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    • v.21 no.2
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    • pp.263-288
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    • 2002
  • 'Science Garden' is a science program that develops acquirements of science & technology at an early stage through experiential study and inspire the spirit of scientific inquiry by carrying out laboratory work, science movie, science lecture, scientific work, outdoor activities, computer classes and science experiment which is hard to do through the regular educational course. It is targeted grade 4,5,6 students during summer and winter vacation. 'Science Garden' is conducted by selective participation freely. It is a wholelistic activity that develops children's potential talents or creativities, improves interest and attitude toward science, and also gives opportunity for self-realization by extending capacity for inquiry to show each student's ability. This study is observed and is compared how it is conducted in elementary school using qualitative study. This study is used narrative observation, in-depth interview and document analysis. Objects of narrative observation are two elementary schools, each from Jellabukdo and Gyeonggido, and 7 teachers were interviewed in-depthly. Here are results of the study. 1 A teacher in school G never takes part in student activities, tends to be indifferent to classes, but focuses on observation and experiment in laboratory. And feedback or evaluation about student's activity is never done. On the other hand, a teacher in school S guides students to understand the principals of science on themselves, and wide variety forms of activities such as role playing, discussion, and games are being done. But an effort to evaluate student's activity is not being made properly. 2. Teachers set a high valuation on the need of 'Science Garden'. Observing the way of conducting 'Science Garden', usually teachers who is in charge of science for official work is selected as a teacher in charge, and groan under a heavy burden of conducting it without anyone's help. Participating students are selected by volunteering or teacher's recommendation, but because of low Participation rate, teachers have difficulty in conducting it. Plan for conducting ‘science Garden’ is made 20 days before it, after getting an official document from Office of Education, refering to booklets produced by National Jungang Science Institute, or data from Office of Education, and internet. Teachers evaluate rarely Most school principals have interest in 'Science Garden' but parents are not well aware of it, The budget is made at the same time with the plan, and scale is varied between 200,000∼500,000 won. Because of the improper way of selecting teacher in charge, difficulty in selecting students, heavy works caused by planning, conducting the program, as well as reporting teacher's work, and lack of parents' awareness, 'Science Garden' has been conducted formally and superficially. Next gives you direction to change, for the right way of conducting' Science Garden'. It is important to motivate competent teachers to instruct students actively. For students' active participation, They should publicize thoroughly beforehand, and develope 'Science Garden' program for teachers to be able to make better use of it. Evaluation of student activities and program should be done in the aspect of developing students’ faculties. Beside of school facilities, they need to put diverse local facilities and places to practical use for immediate natural experience. And not only separate schools but also associated form of schools to conduct it is necessary.

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Technique to Evaluate Safety and Loaded Heavy Equipment Grade in RC Building during Demolition Work (RC건축물 해체공사의 안전성 평가기법 및 탑재장비 등급 제안)

  • Park, Seong-Sik;Lee, Bum-Sik;Kim, Hyo-Jin;Sohn, Chang-Hak
    • Land and Housing Review
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    • v.2 no.2
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    • pp.195-204
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    • 2011
  • During mechanical demolition of RC structures, weights of dismantling equipment and demolition waste of building are applied to unexpected load which did not be considered during the design of structural member. Nevertheless, the loading of dismantling equipment and dismantling process are mainly dependent on field managers' field workers' or experiences without considering safety of structural member by a structural engineer. It is urgently required that reflecting actual circumstance of mechanical demolition, safety evaluation method to evaluate the safety and the guideline for appropriate capacity of structural member to support dismantling equipment weight, be provided. Through site investigation and questionnaire on field workers, this paper proposed demolition waste load, load factor, strength reduction factor, and so on. These are essential to safe evaluation of a building, ready to demolition. Considering actual circumstance of mechanical demolition, safety evaluation method of building and design method of slab and beam was suggested to a dilapidated building. An capability to loading of dismantling equipment was proposed, applied to RC slab and RC beam. Therefore, the suggested safety evaluation method and the guideline for an capability to loading of dismantling equipment weight can reasonably evaluate the capacity of structural member in demolition and use effectively as increasing efficiency and improving safety of demolition through proper management of dismantling equipments.

The Empirical Study on Relationship Between Evaluation Index Characteristics for Occupancy of Business Incubator(BI) and BI Performance : focused on the Moderating Effect of BI Competence (창업보육센터(BI) 입주심사지표특성과 성과의 관계에 관한 실증연구 -BI 역량의 조절효과를 중심으로)

  • Park, Man-Hee;Yang, Dong-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.233-247
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    • 2011
  • With recent increase in growth without employment and unemployment rate, Business Incubator (BI), which is the birthplace of business start-up, is drawing much attention. Therefore, numerous studies had been carried out from the perspectives of efficient operation and performances of BI. Preceding studies at home and abroad were concentrated mainly on the effect of Critical Success Factors of BI on performance, or on internal operational programs or support services of BI. Recently, assertion that potential capacity of companies located in BI at the time of their commencement of occupancy imparts effect on the performance has been presented. Therefore, this Study, in order to pursue research on above issues, will, firstly, analyze the effect of the characteristics of evaluation of companies wishing to be located in BI conducted by each BI, and, secondly, regulation effect of characteristics of evaluation of companies wishing to be located in BI imparted on performance in connection with the work capabilities of BI and capabilities of manager. The results of analysis illustrated that the expertise, among the capabilities of CEO, imparts affirmative effect on the success rate of business start-up. Product competitiveness and marketability displayed affirmative effect on the success rate of business start-up when work capability (operational intensity) is applied. In particular, although the financing capability of CEO of the company located in BI, as an important factor, imparts negative effect on the success rate of business start-up, it implies affirmative regulation effect through the capabilities of manager.