• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.7-17
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• 2009

The development of wireless communication MAC layer is usually released as SoC which is a combination in hardware and software. In this system development environment, an environment for software development and verification is necessary because the hardware development takes a lot of time priori to completion. In integrated development of hardware and software, simulation environment of hardware and software provided by hardware modeling using HDL at RTL and ISS respectively. By increasing the development complexity of system, ESL design modeling systems at higher abstraction level than RTL has already prompted. The ESL design is divided untime model and time model. This paper present design and implementation of MCU for untime model simulation, not time model. Proposed MCU can optimize the system at early step of system development and move up the development completion time by verifying the system function easily and rapidly than part required exact time in untime model. In this paper, we present an MCU module based on SystemC and UC/OS-II Module providing real-time operate system.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.171-177
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• 2009

Optical packet switching(OPS) is a strong candidate for the next-generation internet, since it has a fine switching granularity at the packet level for providing flexible bandwidth, and provides seamless integration between WDM layer and IP layer. Optical packet switching have been studied in two categories: OPS in synchronous and OPS in asynchronous networks. In this article we are focused on contention resolution of OPS in asynchronous networks. The hybrid buffer have been addressed, to reduce packet loss further as one of the alternative buffer structures for contention resolution of asynchronous and variable length packets, which consists of the FDL buffer and the electronic buffer. The OPS design issue for the limited number of TWCs and internal wavelengths is important in the aspect of switch cost and resource efficiency. Therefore, an hybrid buffer structured optical packet switch and its scheduling algorithm is presented for considering the limited number of TWCs and internal wavelengths, for contention resolution of asynchronous and variable length packets. The proposed algorithm could lead to the packet loss improvement compared to the legacy LAUC-VF algorithm with only the FDL buffer.

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.11a
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• pp.0-0
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• 1998

-Part I- As market needs become more various, the production of smaller quantities of a wider variety of products becomes increasingly important. In addition, in order to meet demands for more efficient production, long-term unmanned factory operation is prevailing at a remarkable pace. Within this context, laser machines are gaining increasing popularity for use in applications such as cutting and welding metallic and ceramic materials. FANUC supplies four models of $CO_2$ laser oscillators with laser power ranging from 1.5㎾ to 6㎾ on an OEM basis to machine tool builders. However, FANUC has been requested to produce laser oscillators that allow more compact and lower-cost laser machines to be built. To meet such demands, FANUC has developed six models of Slab type YAG laser oscillators with output power ranging from 150W to 2㎾. These oscillators are designed mainly fur cutting and welding sheet metals. The oscillator has an exceptionally superior laser beam quality compared to conventional YAG laser oscillators, thus providing significantly improved machining capability. In addition, the laser beam of the oscillator can be efficiently transmitted through quartz optical fibers, enabling laser machines to be simplified and made more compact. This paper introduces the features of FANUC’s developed Slab type YAG laser oscillators and their applications. - Part II - All-solid-state lasers employing laser diodes (LD) as a source of pumping solid-state laser feature high efficiency, compactness, and high reliability. Thus, they are expected to provide a new generation of processing tools in various fields, especially in automobile and aircraft industries where great hopes are being placed on laser welding technology for steel plates and aluminum materials for which a significant growth in demand is expected. Also, in power plants, it is hoped that reliability and safety will be improved by using the laser welding technology. As in the above, the advent of high-power all-solid-state lasers may not only bring a great technological innovation to existing industry, but also create new industry. This is the background for this project, which has set its sights on the development of high-power, all-solid-state lasers with an average output of over 10㎾, an oscillation efficiency of over 20%, and a laser head volume of below 0.05㎥. FANUC Ltd. is responsible for the research and development of slab type lasers, and TOSHIBA Corp. far rod type lasers. By pumping slab type Nd: YAG crystal and by using quasi-continuous wave (QCW) type LD stacks, FANUC has already obtained an average output power of 1.7㎾, an optical conversion efficiency of 42%, and an electro-optical conversion efficiency of 16%. These conversion efficiencies are the best results the world has ever seen in the field of high-power all-solid-state lasers. TOSHIBA Corp. has also obtained an output power of 1.2㎾, an optical conversion efficiency of 30％, and an electro-optical conversion efficiency of 12%, by pumping the rod type Nd: YAG crystal by continuous wave (CW) type LD stacks. The laser power achieved by TOSHIBA Corp. is also a new world record in the field of rod type all-solid-state lasers. This report provides details of the above results and some information on future development plans.

• Korean Journal of Community Nutrition
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• v.9 no.2
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• pp.161-172
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• 2004

The dietary habits of middle-aged obese, overweight and normal subjects were evaluated for the purpose of providing the background information of the degenerative disease control. A survey was conducted with 293 subjects (121 males and 172 females) between the ages 40-64 and they were divided into three groups of normal (BMI 18.5-22.9), overweight (BMI 23-24.9) and obese ($BMI\geq25$) based on the criteria of Korean Obesity Association (2000). The mean age of the subjects was $52.0\pm7.3(male)\;and\;51.9\pm6.9$ (female). Socioeconomic levels of subjects belong to the mid-upper class, since 71.9% of the males and 39.5% of the females received above a college education. More than 40% (44.6%) of males and 22.1% of females were obese, and educational background did not affect the obesity rate in males, whereas in females those who received lower education had a higher rate of obesity (p ＜ 0.001). The subjects had a similar degree of drinking to the national average value. but had a lower degree of smoking. The obese group had the higher rate of drinking (p ＜ 0.01) and smoking (p ＜ 0.01). The annual increase in weight, more than 4 kg, was 8.8% for normal group and 30.9% for obese group. However, there were no differences in the mean annual increase in weight among the three groups. In females there were greater tendencies of weight changes in obese group (p ＜ 0.05). About 44.9% of subjects responded that they were exercising regularly, and the obese group appeared to put into practice less than the other groups and to use more strenuous exercise. There was the greater rate of skipping dinner in the obese female group (p ＜ 0.05). The unbalanced dietary pattern was found more with normal group than the other groups (p ＜ 0.01). The food consumption frequency by food groups was not different among the groups. The obese group consumed less frequently meats, vegetables and fruits and had higher frequency in fish, legumes and their products, instant or fast food. In all subjects the higher rate of obesity was found with males than females and with those of heavier smoking and drinking, and in females the higher rate of obesity was found with lower education levels, skipping meals and having an unbalanced diet. In middle-aged subjects of this study with higher educational and socioeconomic background factors contributing to the effects of obesity may include smoking, drinking, educational background, skipping meals or unbalanced dietary pattern. The predictable characteristics for the development of obesity can be defined as sudden fluctuation of weights, exercise regularity and intakes of vegetables and fruits.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.452-460
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• 2017

Rice fields are important stopover sites for the conservation of shorebirds during long-distance migration. These fields serve as food sources providing energy for the next leg of the journey. Shorebirds are able to change their preferred food source at stopover sites. However, the type and distribution of food resources remain unknown for the shorebirds in the Republic of Korea. Therefore, we studied the type and distribution pattern of food resource (macroinvertebrates, remaining rice, and other seeds) for shorebirds in the rice fields. We have identified potential and actual food sources for shorebirds in the rice fields. The potential food sources were collected by using a core-sampling method and the actual food source was ascertained by observational analysis. As a result, a total 19 species of benthic macroinvertebrates in 15 families were recorded as potential food sources. A total of 9 families in 9 orders of benthic macroinvertebrates known to be actual food sources were also recorded during the study period, including loaches, and a tuber of sea club rush. Also, the distribution of the food source depended on soil conditions generated by cultivation such as plowing, harrowing, and the use of pesticides. In the present study, we identified the type and distribution of food sources for shorebirds. This information can be used as essential primary baseline data for conservation of shorebirds using the rice fields of the Republic of Korea.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.80-89
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• 2017

This study aims to get necessary information for designing the systematic and practical career preparation education program by checking the differences among core competency of collegiate and career variables. In order to do that, the core competence of collegiate was identified through Korea collegiate essential skills assessment(K-CESA), and the survey results about career preparation behavior, career decision-making self efficacy and career barriers were collected. And then the data were compared and analyzed to differentiate relationships among core competency of collegiate and career variables, based on the university types and the locations. The data were analyzed by ANOVAs and t-tests using the SPSS 21.0 program. According to the analysis, firstly, there is a difference in the level of collegiate essential skills depending on the characteristics of schools. Secondly, the students at metropolitan four-year universities feel more difficulties primarily in the variable of career barriers than the students at local universities and students at colleges. Thirdly, the students of high rank at core competence showed higher career decision-making self-efficacy and career preparation behavior than the students of low rank, and they feel less difficulties in the matter of career barrier. This study shows that in order to support students' career efficiently, it is necessary for each college and university to design career program by considering the core competency and the level of career development of students, instead of providing them with a unified and fractional program.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1025-1036
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• 2003

In industry, it is a current trend that systems are developed by using Enterprise JavaBeans(EJB) technology for reducing the cost and the time. Thus, the architecture of EJB is getting more essential to enhance reusability, extensibility and portability of system. However little has been studied in the realm of the practical software architectures for EJB. The architecture has just bean studied in abstract level, but not in concrete level providing the method to substantiate it using the practical J2EE techniques. Just using the EJB technology doesn't guarantee the reusability of the artifacts because EJB specification provides the characteristics and architecture for only fine grained components as session and entity bean. In this paper, we propose the enterprise software architecture for the systems based on EJB and the concrete techniques for implementing that. Also, design patterns of modeling efficient enterprise architecture are represented. By analyzing both the strengths and the weaknesses of suggested design patterns, EJB design patterns which are suitable for each layer of enterprise architecture will be identified. Through the component which design patterns are applied, the architecture can support the optimized relationship between the components. Five techniques for designing components from fine grained to coarse grained based on EJB technology, and architecture design techniques including transaction and assembling techniques are proposed.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.264-270
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• 2018

In recent years, It is required to verify software reliability according to DO-178, which announced by radio technical commission for aeronautics (RTCA) and recognized by the Federal Aviation Administration (FAA), for civil aircraft developed or intended to fly in the United States or Europe. This is because the reliance on software in each field is deepening, and the efforts for improvement of software reliability have been made first in civil aviation field where economic and social impacts are catastrophic in the event of an accident. In this paper, we have identified some issues to be considered for requirements-based reliability verification required by DO-178 to improve software reliability and present the major elements of the present weapon system acquisition procedure of DAPA for each stage. In addition, we analyzed the results of applying the identified main check factors to a domestic aircraft development project based on the information accumulated in overseas aircraft development projects. As a result, we have shown that it is possible to verify requirements-based software reliability according to DO-178 by adding key checkpoints to the current weapon system acquisition procedure and providing objective inspection criteria.

• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.581-591
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• 2005

Collaborative filtering systems have problems involving sparsity and the provision of recommendations by making correlations between only two users' preferences. These systems recommend items based only on the preferences without taking in to account the contents of the items. As a result, the accuracy of recommendations depends on the data from user-rated items. When users rate items, it can be expected that not all users ran do so earnestly. This brings down the accuracy of recommendations. This paper proposes a collaborative recommendation method for extracting typical group preferences using user-item matrix optimization and user profiles in collaborative tittering systems. The method excludes unproven users by using entropy based on data from user-rated items and groups users into clusters after generating user profiles, and then extracts typical group preferences. The proposed method generates collaborative user profiles by using association word mining to reflect contents as well as preferences of items and groups users into clusters based on the profiles by using the vector space model and the K-means algorithm. To compensate for the shortcoming of providing recommendations using correlations between only two user preferences, the proposed method extracts typical preferences of groups using the entropy theory The typical preferences are extracted by combining user entropies with item preferences. The recommender system using typical group preferences solves the problem caused by recommendations based on preferences rated incorrectly by users and reduces time for retrieving the most similar users in groups.

• Journal of KIISE:Software and Applications
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• v.26 no.11
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• pp.1359-1371
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• 1999

대규모 네트워크 상에서 동작하는 분산 시스템의 구현을 위해 제시된 방법 중의 하나인 이동 코드 개념은 네트워크 공유 자원에 접근할 수 있는 효과적인 방법을 제시하였고 이 개념을 지원하는 많은 언어들의 개발을 가져왔다. 개발된 언어들이 가지고 있는 이동 코드를 지원하기 위한 언어 구문과 적용하려는 문제 영역의 특성을 반영한 언어 구문은 네트워크 프로그래밍을 하는데 있어서 효율과 문제 중심의 프로그램의 두 가지를 모두 가능하게 하고 있다. 본 논문에서는 현재 분산 컴퓨팅 환경에서 가장 많이 사용되고 있는 클라이언트-서버 모델을 확장하여 서버의 자원에 접근할 수 있는 또 다른 방법을 가진 모델을 제시하고, 이 모델을 표현할 수 있는 언어를 설계하였다. 설계된 언어는 이동 코드의 개념을 지원함으로써 대규모 네트워크에서 수행되는 프로그램의 작성을 가능하게 하고, 분산 범위 규칙을 채택함으로써 이동 코드의 기술을 일반 함수를 기술하듯 명확한 관점에서 할 수 있도록 하였다. 또한 네트워크 관련 자원들을 언어 구문으로 채택하여 네트워크 프로그래밍을 언어 수준에서 할 수 있도록 하였다. 언어의 이론적인 설계에 그치지 않고 설계된 언어를 수행할 수 있는 실행 시간 지원 시스템을 구현하였다. 실행 시간 지원 시스템은 언어를 해석하고 실행하는 코드 해석기와 이동 코드를 지원하는 네트워크 감독으로 구성되며 설계된 언어를 사용하여 실제로 네트워크 응용 프로그램을 작성하고 테스트 해 볼 수 있다.Abstract Some studies bring up a concept of code mobility as an innovative way to access network resources in order to develop distributed systems working on a large scale network. After that, many languages are suggested to support this concept. In these languages, language constructors for their particular application domains and mobile codes provide both problem-oriented views to the programmer and reasonable performance to the system. In this thesis, we extend the client-server model that is the most popular model in developing distributed systems these days. We propose a model to have another method to access server's resources and extend the C language to implement the proposed model for the large scale network. The new language has capability to build a software working on a large scale network by supporting mobile code and gives a consistent network programming view to the programmer by adapting distributed semantics. The language also makes network programming easy by providing network primitives at the language level. We implement a prototype of run-time system to support this language. The run-time system is composed of two major parts: code-interpreter that interprets and executes the language and network-daemon that supports mobile codes.