• Title/Summary/Keyword: Operating Practices

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Improving the Read Performance of Compressed File Systems Considering Kernel Read-ahead Mechanism (커널의 미리읽기를 고려한 압축파일시스템의 읽기성능향상)

  • Ahn, Sung-Yong;Hyun, Seung-Hwan;Koh, Kern
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.6
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    • pp.678-682
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    • 2010
  • Compressed filesystem is frequently used in the embedded system to increase cost efficiency. One of the drawbacks of compressed filesystem is low read performance. Moreover, read-ahead mechanism that improves the read throughput of storage device has negative effect on the read performance of compressed filesystem, increasing read latency. Main reason is that compressed filesystem has too big read-ahead miss penalty due to decompression overhead. To solve this problem, this paper proposes new read technique considering kernel read-ahead mechanism for compressed filesystem. Proposed technique improves read throughput of device by bulk read from device and reduces decompression overhead of compressed filesystem by selective decompression. We implement proposed technique by modifying CramFS and evaluate our implementation in the Linux kernel 2.6.21. Performance evaluation results show that proposed technique reduces the average major page fault handling latency by 28%.

Sensor Network Simulator for Ubiquitous Application Development (유비쿼터스 응용 개발을 위한 센서 네트워크 시뮬레이터)

  • Kim, Bang-Hyun;Kim, Jong-Hyun
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.6
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    • pp.358-370
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    • 2007
  • Software simulations have been widely used for the design and application development of a wireless sensor network that is an infrastructure of ubiquitous computing. In this study, we develop a sensor network simulator that can verify the behavior of sensor network applications, estimate execution time and power consumption, and simulate a large-scale sensor network. To implement the simulator, we use an instruction-level parallel discrete-event simulation method. Instruction-level simulation uses executable images loaded into a real sensor board as workload, such that it results in the high degree of details. Parallel simulation makes simulation of a large-scale sensor network possible by distributing workload into multiple computers. The simulator can predict the amount of power consumption based on operating time of modules in a sensor node and counting the number of executed instructions by kind. Also it can simulate ubiquitous applications with various scenarios and debug programs. Instruction traces used as workload for simulations are executable images produced by the cross-compiler for ATmega128L microcontroller.

A Status Report on Dual Energy X-ray Absorptiometry Quality Control in Korea (이중에너지 방사선흡수 골밀도 장치의 품질관리 현황)

  • Kim, Jung-Su;Rho, Young-Hoon;Lee, In-Ju;Kim, Sung-Su;Kim, Kyoung-Ah;Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.527-534
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    • 2016
  • Dual-energy X-ray absorptiometry (DEXA) is the most widely used technical instrument for evaluating bone mineral content (BMC) and density (BMD) in patients of all ages. In 2016, DEXA devices operating is 5617 in Korea. In this study we investigated the quality of management practices survey for DEXA equipment and we analyzed it. We got a survey response rate of 12.6%. Accurate bone densitometry test is used data for estimation a patient's risk of fracture. However, improper bone densitometry will increase the possibility of causing a false positive. Therefore. it is essential to use the proper aids accurate bone densitomenty to be performed, and the quality control of the device to reduce the error factor of the tester through the training to reduce error for the device and the attitude.

A Mapping Method for a Logical Volume Manager in SAN Environment (SAN 논리볼륨 관리자를 위한 매핑 기법)

  • 남상수;송석일;유재수;김창수;김명준
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.6
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    • pp.718-731
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    • 2003
  • SAN(Storage Area Network) was developed in response to the requirements of high availability of data, scalable growth, and system performance. In order to use the SAN more efficiently, most of the SAN operating software supports storage virtualization concepts that allow users to view physical storage devices of the SAN as a large volume. A logical volume manager plays a key role in storage virtualization. It realizes the storage virtualization by mapping logical addresses to physical addresses. In this paper, we design and implement an efficient and flexible mapping method for the logical volume manager. Additionally we also design and implement a free space management method for flexible mapping. Our mapping method supports a snapshot that preserves a volume image at certain time and on-line reorganization to allow users to add or remove storage devices to and from the SAN even while the system is running. To justify our mapping method, we compare it with the mapping method of the GFS (Global File System) through various experiments.

Policy Plans for the Maintenance of Public Security of Living During the War (전시 국민생활안정 유지방안)

  • Kil, Byung-Ok
    • Journal of National Security and Military Science
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    • s.5
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    • pp.131-172
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    • 2007
  • Government duties in the cases of crisis are aimed at supporting efficient military operations in the fields of non-military affairs and resource mobilization, maintenance of government functions, and search for the public security of living during the war. In crisis, the government must change its functions into the total-war system with all resources available for the efficient performance of military operations, war economy, public safety and security as well as government continuance. The main contents of "Chung-Mu Plan" include the alternative measures to control the circulation of life necessities, emergency electricity, water and gas; recover public facilities from the disaster; and accommodate the wounded and refugees. Governments have practiced Ul-chi and ChungMoo exercises to improve government's management capabilities and master standard operating procedures including systematic distribution plans in the national and local level. However, such plans have not yet sufficient enough for the maintenance of public security of living. In addition to the conceptual ambiguity, major problems are the inappropriate system of the war economy, legal institutions, and administrative SOPs for the efficient maintenance of it. Thus, for the betterment of national crisis management system, the government should have the manual stated from every step and level dealing with crisis to the legal institutions. It is important to empower the National Emergency Planning Commission for the policy consistency and efficient/effective implementation. The comprehensive plans must have an integrated cooperative system of the central/local governments, military and civil society with actual practices and exercises for the maintenance of the public security of living.

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Applying Design Pattern & Refactoring on Implementing RTOS for the Small Educational Multi-Joint Robot (소형 교육용 다관절로봇 RTOS 구현을 위한 디자인 패턴 & 리팩토링 적용)

  • Son, Hyun-Seung;Kim, Woo-Yeol;Ahn, Hong-Young;Kim, Robert Young-Chul
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.217-224
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    • 2009
  • The traditional small educational multi-joint robots were developed on firmware. In these system's case, we cann't give a chance to educate good practices due on executing just robot's simple movements. But it may be possible for RTOS to control the elaborate movement of the robot with assembling each part on firmware. With this RTOS, we can enhance the efficiency of robot's movements, but too difficult to use the education as increasing the complexity of robot system. To solve the problem, we apply with Design pattern and Refactoring for the Education. Applying robot's design with Design pattern and Refactoring. There may be easily understand what and how to design RTOS for any level ones. We may easily change/upgrade RTOS for new system with this approach. This paper mentions to design RTOS with Design patterns and to apply RTOS's source code with Refactoring.

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A Preliminary Establishment of Dose Constraints for the Member of Public Taking into Account Multi-unit Nuclear Power Plants in Korea (국내 복수호기 원전 운영을 고려한 일반인 선량제약치 설정에 대한 고찰)

  • Kong, Tae-Young;Choi, Jong-Rack;Son, Jung-Kwon;Kim, Hee-Geun
    • Journal of Radiation Protection and Research
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    • v.37 no.3
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    • pp.129-137
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    • 2012
  • In the 2007 recommendation, the ICRP evolves from the previous process-based system of practices and intervention to the system based on the characteristics of radiation exposure situation. In addition, ICRP recommends the application of source-related dose constraints under the planned exposure situation as a tool for the optimization of protection to workers and the member of public. In this study, the analysis of radioactive effluents from Korean nuclear power plants and the public dose assessment were conducted in reference with the use of dose constraints. Finally, the measure to implement the dose constraints for the member of public was suggested taking into account multi-unit reactors operating at a single site in Korea.

Qualitative Study on Improvement of Operating System and Tailored Nutrition Education Program for Marriage Immigrants to Korea: Program Providers' Perspective (다문화가정 맞춤형 영양교육 프로그램과 운영시스템 개선을 위한 질적 연구 : 프로그램 제공자 측면)

  • Joe, Mee-Young;Hwang, Ji-Yun
    • Korean Journal of Community Nutrition
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    • v.22 no.4
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    • pp.323-335
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    • 2017
  • Objectives: The purpose of this study is to analyze the current status of nutrition education programs for multicultural families and to provide policy suggestions for improvement. Methods: In-depth interviews of a total of 21 multicultural experts were conducted; 15 people were interviewed individually, while 6 people were interviewed in groups of three. Results: In-depth interviews revealed various problems related to the operation of nutrition education programs. The causes of problems were analyzed and categorized as four factors: systemic, practical, environmental and cultural. As for the systematic factors, insufficient linkage between related organizations and duplicate performance of several projects were identified as concerns Establishment of a control tower and strengthening the linkage among the related organizations may be needed to address this concern. With regard to practical factors, the study identified that language barriers, and lack of nutritional education media and tools translated into multicultural languages were limiting factors. These limitations the development of nutrition education materials that aretranslated into multiple languages, implementation of education programs that are different from the Korean education, and by providing interpreters. As for the environmental factors, low educational level and poor nutritional knowledge of multicultural women made it difficult for them to understand the contents of the education. Demonstration, practical training and urgent education on pregnancy and childbirth nutrition were identified as needs to address these concerns. Withregard to cultural factors, food culture conflict with Korean families, and difficulties in home practices were detected as concerns. Participants in the study suggested that getting education with family and facilitation of weekend and nighttime programs health of this community. Conclusions: Further studies are needed to adopt more effective and efficient nutrition intervention to promote the healthy eating of the married immigrant women based on the study results.

A Study on the Medical Program and Space Configuration for Veterinary Medical Teaching Hospital - Focused on the Analysis of Veterinary Medical Teaching Hospital built in the last ten years of Korea (수의과대학 반려동물병원의 프로그램 및 공간구성에 관한 연구 - 최근 10년 내에 준공 된 국내 수의과대학 동물병원 분석을 중심으로)

  • Kim, Dohyeon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.3
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    • pp.71-80
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    • 2017
  • Purpose: At the moment prevention and treatment of animal related diseases is becoming a social concern as the demand for animal increases. Furthermore, The design of the veterinary medical teaching hospital are even more complex because they have to accommodate medical program for animal and education and research program for students. However, there are a few experience and useful guidelines for the planning of the veterinary medical teaching hospital. So it is not easy for the regional hub universities to work out the proper plan for the construction of the veterinary medical teaching hospital for their own. This study has been started in order to provide basic informations for the planning of Korean veterinary medical teaching hospital. Methods: Interview to veterinarian, intern and employee of the veterinary medical teaching hospital and Field surveys to veterinary medical teaching hospital in Korea have been conducted for the data collection. The drawings of three universities of veterinary medical teaching hospital have been analysed and diagramed. Results: The result of this study can be summarized into three points. The first one is that the veterinary medical teaching hospital spaces are divided into five areas (ambulatory care, central medical care, hospitalization, education and research, operations and support) and each area is divided independently and connected properly. The second one is that the veterinary medical teaching hospital differs from hospital in the detailed space plan in the sense that the animal is a patient. The third one is that each hospital has different operating practices and programs according to local conditions Implications: It is meaningful as a basic source of veterinary medical teaching hospital design in the future.

An Extension to Time-out Facility in C Language for Embedded Real-Time Programming (내장 실시간 프로그래밍을 위한 C 언어의 타임아웃 기능의 확장)

  • Lee, Sheen;Yang, Seung-Min
    • Journal of KIISE:Computing Practices and Letters
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    • v.8 no.4
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    • pp.423-429
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    • 2002
  • Time-out is one of the basic but important functions in real-time programming. However, the C language used commonly in the embedded real-time systems doesn't support this capability. For this capability, there have been numerous studies on language extension and/or special purpose real-time kernel (or engine). Those require preprocessor or new kernel support. In this paper, we propose a time-out facility supported by a library and some macro functions with a minimum dependency on operating systems. Furthermore, we also provide a structured _within statement, a macro function which makes programming easy. We have implemented this for the LINUX and the DOS environment, and for the POSIX multithread environment as well.