• Title/Summary/Keyword: Bottleneck

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A Study on the Student Guidance at Home Management House (가정관리실습관에 있어서의 학생지도에 관한 연구 - 서울 시내모여자대학교대상-)

  • 김복길
    • Journal of the Korean Home Economics Association
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    • v.12 no.34
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    • pp.679-697
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    • 1974
  • I. Preface A. Establishment. There are many psycological and physiological difficulties that students have made practical application to a building site of 600 pyung and a structure of 65 pyung each sixteen students in the Home Management House, but there exists problem in students apprentice and management of professors. B. Purpose of study This research aim to seek a high degree of efficiency approach in investigating, studying and analyzing factors of the problem in Home Management which have been faced in women colleges in seoul. C. Content of study. This study is aim at finding out the problems including facilites, system, guiding principle, working bottleneck and administrative problem in making practical application of Home Management. II. A plan and method of study A. This subject of statiscal research is 616 women students in senior year from september 27 1970 to October 31 1974. The rate of collection of questionnaire is 100 percent. B. The Method of study is devised through refering documents, interview with students, questionnaire and observation. III. Result of study Of the total of 29 university in seoul, 24 Universities have its Course of Home Economic among which only 12 have Home Management for making practical application. Home Management House for making practical application is located mainly in campus but some of them exceptimally are in outside university. Students practice mainly at civilzed resident, apartment, bangalow so forth, and demention of which occupies approxiamtely 50-600 pyung (land) and 20-70 pyung (Building). A member with 4 or 20 students make practical application from 10 days to 3 months. A member consists of students and assistant teacher, and practice site classifies into living school for Professors living, and another school for Professors and assistant teachers. Answer to a questionnaire. 616 students answer to a questionnaire. 49 Perfect of 616 students like to have a member with 12 students like to have a member with 12 students, 38 percent student a member with 16 students. About the period of making practical About the period of making practical application, 76 percent students like to have two or three week period. 19 percent students think it a short period and 4 percent students think it a long period. There is none who thinks 25 day period day period to be short. About making practical application, 66 percent of 616 students feel uneasy, 40 percent students feel lack of sleep and tired. Students take a pleasure in having a conversation with their friends, inviting their mother, having dinner-party and birthday party. 77 percent students want to invite their father and 67 percent students want to invite their boy-friends. It is hard to have a good personal relation about the great the result of practice, students acknowledge themselves that they have learned about Cautiousness and they are sure of good Home Manager. There are 9 difficult problems during the period. IV. Summary discussion a. Many problems come from having a number of students. b. Students feel tired with their practice if over three weeks. No Matter how good a plan is, it useless if students can't adapt themselves to it. Suggestions 1) it is good to have a member with 5 or 6 students, and it is suitable to have two or three week period, and to have an area of 20 or 30 pyung. 2) it's proposed a profess or to live together in making practical application of Home Management 3) it is proposed a professor to have a sure T.O. and to be treated better.

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Round Robin(RR) ONE-IP: Efficient Connection Scheduling Technique for Hosting Internet Services on a Cluster of Servers (서버 클러스터에서의 인터넷 서비스를 위한 효율적인 연결 스케줄링 기법)

  • 최재웅;김성천
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.04a
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    • pp.736-738
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    • 2001
  • 웹을 사용하는 사용자들의 급속도로 증가하는 서비스 요청을 신속하고 저렴한 비용으로 처리하기 위한 대응책으로, LAN 환경의 웹 서버 클러스터 구조가 각광을 받고 있다. 높은 가용성 및 확장성을 보장하는 웹 서비스를 제공하기 위해 많은 부하의 서비스 요구를 여러 서버에게 효과적으로 나누어 처리할 수 있어야 하며, 따라서 서비스 요청 패킷을 고르게 분배할 수 있는 합리적인 스케줄링 기법을 필요로 한다. ONE-IP 스케줄링 기법은 이더넷의 브로드케스트 메시지에 의해 스케줄링이 분산되도록 하는 전략을 사용함으로써, 클러스터에 유입되는 패킷의 집중화로 인해 발생할 수 있는 병목 현상(bottleneck)과 치명적인 오류(Single-point of Failure) 문제를 효과적으로 해결하였다. 그러나, 서비스를 요청하는 패킷의 발신지 주소만을 이용하는 단순한 패킷 스케줄링을 사용하기 때문에 클러스터를 구성하는 서버들 간의 부하 불균형을 가중시키며, 결과적으로 클러스터의 효율성을 저하시키는 문제점을 가지고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 RR ONE-IP 기법을 제안하였다. 제안한 기법은 서버에 할당되는 부하간에 불균형이 발생하는 문제점을 해결하기 위해 TCP 연결 단위의 스케줄링 전략을 사용하였으며, 서버의 부하 정보를 이용하지 않는 RR 스케줄링 기법을 도입함으로써, ONE-IP 기법의 장점을 그대로 유지하면서 보다 나은 부하의 균등한 분배로 시스템의 처리 능력을 향상시키도록 하였다. 또한, 실험을 수행한 결과 제안한 기법이 기존의 기법에 비해 평균 3.84%의 시스템의 성능 향상을 보였으며, 과부하 발생율에서는 평균 23.5%의 감소를 가져왔음을 보였다.우 단어 인식률이 43.21%인 반면 표제어간 음운변화 현상을 반영한 1-Best 사전의 경우 48.99%, Multi 사전의 경우 50.19%로 인식률이 5~6%정도 향상되었음을 볼 수 있었고, 수작업에 의한 표준발음사전의 단어 인식률 45.90% 보다도 약 3~4% 좋은 성능을 보였다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아이에서 그 주산기사망률(周産基死亡率)

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NS2 based Simulator for Performance Evaluation of P2P Streaming Systems (P2P 스트리밍 시스템의 성능 평가를 위한 NS2 기반 시뮬레이터 개발)

  • Kim, Hye-Sun;Hwang, Ki-Tae
    • The KIPS Transactions:PartD
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    • v.14D no.5
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    • pp.555-564
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    • 2007
  • Internet streaming systems consist of a media server, a streaming sewer, and terminals. The media server delivers multimedia contents such as video and/or audio to the streaming server, which distributes the contents to terminals as well. Existing Internet streaming systems have a bottleneck problem in the streaming server because of the limit of the processing capacity of the streaming server and therefore a streaming server can not accomodate more terminals than the limit. As a solution to this problem, P2P streaming systems have been lately proposed and investigated, using P2P distributed architectures. Actually, however, there exist many difficulties in the design and implementation of P2P streaming systems, because it needs many real computers and various network constructions. In this paper, we have proposed and defined a P2P streaming system model such as the architectural model, the timing model, the behavior model, and the performance metrics. And also we have implemented an NS2 based P2P streaming system simulator called P2PStreamSim. Finally, we have verified it through test simulations and analyzed the results.

A Study on the Structuring of Professional System for Design Business (전문적 체계정립을 위한 디자인비즈니스 유형구조화 연구)

  • 김보영
    • Archives of design research
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    • v.17 no.3
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    • pp.17-26
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    • 2004
  • Those of the growth of e-business, the development of the cultural creative industry, the contents and knowledge industry have expanded and diversified the existing business models and created new ones. They are triggering new interpretations and discussions on business models. Such of changing business environment has paved the way for the expansion of design management within the design industry and opened new windows of opportunity for the traditionally small and non-specialized design business. Until now, the design business has not been distinguished from design industry or design service, and has not been viewed as an independent field. Rather, the design business has merely been part of a process. As such, the lack of dear definition and structured system had been a bottleneck for many design companies trying to achieve capital and social success and establish the foundation for growth and for companies striving to advance the design management in developing design business models or growth strategy in line with the changing environment. Against these sort of backdrops, this paper attempts to dearly define the design business. To this end, the paper tries to developed a design business model framework which classifies design business model into four types - customized, ready-made, provider and contract - according to the business activities between the producer and the end user, and business items into product, additional sonics, knowledge and promotion. The framework will expand the definition of design business and contribute to the expansion of design business activities and the development of diverse business models.

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Physiological and Ecological Characteristics of Lipid-Producing Botryococcus Isolated from the Korean Freshwaters (한국산 고지질 미세조류 Botryococcus의 분포 및 생장 특성)

  • Shin, Sang-Yoon;Jo, Beom-Ho;Lee, Hyung-Gwan;Oh, Hee-Mock
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.288-294
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    • 2013
  • Recently, sustainable production of biofuel using algal biomass is being pursued because of its enormous potential. First and foremost, securing superior strains to develop an efficient production system for algal biodiesel through screening or genetic improvement of microalgae is necessary. The genus of Botryococcus is regarded as one of the superior microalgae for biodiesel production due to its ability to accumulate high amounts of lipids and hydrocarbons. However, its low growth rate is a bottleneck for large-scale production and commercialization. The purpose of this study is to obtain indigenous Botryococcus strains which possess high lipid content and biomass productivity. The Botryococcus sp. was isolated from the Seobu Reservoir in Jeju Island and identified as Botryococcus sudeticus J2 by comparative analysis of 18s rRNA gene and ITS regions. The biomass productivity and lipid content of B. sudeticus J2 were 0.116 g $L^{-1}day^{-1}$ and 40.1% of dry wt., respectively. This was higher than the value of B. braunii UTEX 572, which is widely regarded as a superior strain among Botryococcus species. The relatively high growth rate of B. sudeticus J2 was achieved under a light intensity of 240 ${\mu}mol$ photons $m^{-2}s^{-1}$ with ambient air spargingwhen compared to 120 ${\mu}mol$ photons $m^{-2}s^{-1}$ with 2% $CO_2$ supply. In summary, it is likely that the isolated B. sudeticus J2 can be used for the mass cultivation and biodiesel production.

A study on the improvement of work flow and productivity in complex manufacturing line by employing the effective process control methods (복잡한 생산라인에서 효율적 공정관리 기법 도입에 따른 공정흐름 및 생산성 개선 연구)

  • Park, Kyungmin;Jeong, Sukjae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.305-315
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    • 2016
  • Due to the change from small volume production to small quantity batch production systems, individual companies have been attempting to produce a wide range of operating strategies, maximize their productivity, and minimize their WIP level by operating with the proper cycle time to defend their market share. In particular, using a complex workflow and process sequence in the manufacturing line has some drawbacks when it comes to designing the production strategy by applying analytical models, such as mathematical models and queueing theory. For this purpose, this paper uses three heuristic algorithms to solve the job release problem at the bottleneck workstation, product mix problem in multi-purpose machine(s), and batch size and sequence in batch machine(s). To verify the effectiveness of the proposed methods, a simulation analysis was performed. The experimental results demonstrated that the combined application of the proposed methods showed positive effects on the reduction of the cycle time and WIP level, and improvement of the throughput.

A $CST^+$ Tree Index Structure for Range Search (범위 검색을 위한 $CST^+$ 트리 인덱스 구조)

  • Lee, Jae-Won;Kang, Dae-Hee;Lee, Sang-Goo
    • Journal of KIISE:Databases
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    • v.35 no.1
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    • pp.17-28
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    • 2008
  • Recently, main memory access is a performance bottleneck for many computer applications. Cache memory is introduced in order to reduce memory access latency. However, it is possible for cache memory to reduce memory access latency, when desired data are located on cache. EST tree is proposed to solve this problem by improving T tree. However, when doing a range search, EST tree has to search unnecessary nodes. Therefore, this paper proposes $CST^+$ tree which has the merit of CST tree and is possible to do a range search by linking data nodes with linked lists. By experiments, we show that $CST^+$ is $4{\sim}10$ times as fast as CST and $CSB^+$. In addition, rebuilding an index Is an essential step for the database recovery from system failure. In this paper, we propose a fast tree index rebuilding algorithm called MaxPL. MaxPL has no node-split overhead and employs a parallelism for reading the data records and inserting the keys into the index. We show that MaxPL is $2{\sim}11$ times as fast as sequential insert and batch insert.

A Performance Improvement of Linux TCP/IP Stack based on Flow-Level Parallelism in a Multi-Core System (멀티코어 시스템에서 흐름 수준 병렬처리에 기반한 리눅스 TCP/IP 스택의 성능 개선)

  • Kwon, Hui-Ung;Jung, Hyung-Jin;Kwak, Hu-Keun;Kim, Young-Jong;Chung, Kyu-Sik
    • The KIPS Transactions:PartA
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    • v.16A no.2
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    • pp.113-124
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    • 2009
  • With increasing multicore system, much effort has been put on the performance improvement of its application. Because multicore system has multiple processing devices in one system, its processing power increases compared to the single core system. However in many cases the advantages of multicore can not be exploited fully because the existing software and hardware were designed to be suitable for single core. When the existing software runs on multicore, its performance improvement is limited by the bottleneck of sharing resources and the inefficient use of cache memory on multicore. Therefore, according as the number of core increases, it doesn't show performance improvement and shows performance drop in the worst case. In this paper we propose a method of performance improvement of multicore system by applying Flow-Level Parallelism to the existing TCP/IP network application and operating system. The proposed method sets up the execution environment so that each core unit operates independently as much as possible in network application, TCP/IP stack on operating system, device driver, and network interface. Moreover it distributes network traffics to each core unit through L2 switch. The proposed method allows to minimize the sharing of application data, data structure, socket, device driver, and network interface between each core. Also it allows to minimize the competition among cores to take resources and increase the hit ratio of cache. We implemented the proposed methods with 8 core system and performed experiment. Experimental results show that network access speed and bandwidth increase linearly according to the number of core.

Planning Evacuation Routes with Load Balancing in Indoor Building Environments (실내 빌딩 환경에서 부하 균등을 고려한 대피경로 산출)

  • Jang, Minsoo;Lim, Kyungshik
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.7
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    • pp.159-172
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    • 2016
  • This paper presents a novel algorithm for searching evacuation paths in indoor disaster environments. The proposed method significantly improves the time complexity to find the paths to the evacuation exit by introducing a light-weight Disaster Evacuation Graph (DEG) for a building in terms of the size of the graph. With the DEG, the method also considers load balancing and bottleneck capacity of the paths to the evacuation exit simultaneously. The behavior of the algorithm consists of two phases: horizontal tiering (HT) and vertical tiering (VT). The HT phase finds a possible optimal path from anywhere of a specific floor to the evacuation stairs of the floor. Thus, after finishing the HT phases of all floors in parallel the VT phase begins to integrate all results from the previous HT phases to determine a evacuation path from anywhere of a floor to the safety zone of the building that could be the entrance or the roof of the building. It should be noted that the path produced by the algorithm. And, in order to define the range of graph to process, tiering scheme is used. In order to test the performance of the method, computing times and evacuation times are compared to the existing path searching algorithms. The result shows the proposed method is better than the existing algorithms in terms of the computing time and evacuation time. It is useful in a large-scale building to find the evacuation routes for evacuees quickly.

Using Balanced Scorecard to Explore Learning Performance of Enterprise Organization

  • Chiu, Chung-Ching;Tsai, Chih-Hung;Chung, Yi-Chan
    • International Journal of Quality Innovation
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    • v.8 no.1
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    • pp.40-75
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    • 2007
  • In the early industrial age which with high intensity of machine and labor, using financial measurement index was good enough to tie in company's mechanization and philosophy of management and been in efficiency. But being comply with "New Economic age," a new economic environment is full of knowledge and information, the enterprise competition had changed from tangible assets, plants to intangible innovation ability of knowledge. As recognizing the new tendency by enterprise, they value gradually the growth and influence from learning. Practice of organization learning not only needs firm structure and be in coordination with both hardware and software, but also needs an affect measurement model to offer enterprise to estimate learning performance. It's a good instrument of financial performance measure mold in the past years, But it's for measuring the past, couldn't formulate enterprise trend to future, hard to estimate investment for future, such as development of products, organization learning, knowledge management etc, as which intangible assets and knowledge ability just the key factors of being win around competition environment in the future. In 1992, Kaplan and Norton brought up Balance Scorecard (BSC) on Harvard Business Review, as an instrument helping enterprise to measure performance, which is being considered to be a most influence management instrument. It added non-financial index such as customer, internal process and learning growth besides traditional financial index, as offering enterprise an index to measure and manage intangible assets and intellectual property. As being aware of organization learning is hard to be ignored in the new economic age, this research is based on learning and growth of BSC, and citing one national material company try to let the most difficult measurement performance of organization learning, to be estimate through BSC, analyze of factor and individual case, to discuss the company how to make the related strategy and vision of organization learning to develop learning and growth of the structure of BSC, subject the matter of out put factors to be discussed, and measure the outcomes as a result of research. The research affect offers (1) the base implement procedure of carrying out BSC; (2) the reference of formulating measurement index while enterprise using BSC to estimate performance of organization learning; (3) the possibility bottleneck maybe forcing while carrying out BSC, to be an improvement or preventive for enterprise.