• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.166-180
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• 2000

Recommendations of ITU-T and ISO stipulate the managerial abstraction of static and dynamic characteristics of network elements, management functions as well as management communication protocol. The current recommendations provide the formal mechanism for the structural parts of managed objects such as managed object class and attributes. But the current description method does not provide the formal mechanism for the behavioral characteristics of managed objects in clear manner but in natural language form, the complete specification of managed objects is not fully described. Also, the behaviour of managed objects is affected by their temporal and active properties. While the temporal properties representing periodic or repetitive internals are to describe managed objects behaviour in rather strict way, it will be more powerful if more dynamic temporal properties determined by external conditions are added to managed objects. In this paper, we added dynamic features to scheduling managed objects, and described, in GDMO, scheduling managed objects that support dynamic features. We also described behaviour of managed objects in newly defined BDL that has dynamic temporal properties. This paper showed that dynamic temporal managed objects provide a systematic and formal method in agent management function model.

• Korean Journal of Construction Engineering and Management
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• v.17 no.5
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• pp.22-34
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• 2016

The Project Delivery System (PDS) is used in mixed way without clear classification from tendering system and the standard itself that can be selected is set with project budget or estimated cost only. Essentially, the PDS should consider and reflect project characteristics and types, internal and external factors for the purpose of improving the lives of citizens and their welfare. However, the current status is not operated flexibly due to the given budget, period and uniform laws and regulations. In order to solve this problem, this study suggests a Decision Support Model to select the optimal PDS for public construction projects. The current problem of the PDS for public construction projects were identified and the application of a decision support model was proposed. Subsequently a decision-making model was suggested for each PDS using the identified factors and linear discriminant function of discriminant analysis. An additional questionnaire survey and actual practical case analysis were carried out to verify the effectiveness and applicability of the model to actual work. It can be used by adjusting the decision support model and detailed factors according to the specific characteristics of public organization, ability of person in charge and project type.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.762-767
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• 2016

High thermal efficiency and the ability to use various types of fuel are a few of the many advantages of diesel engines. However, a major disadvantage is that their exhaust emissions are more harmful to humans and the environment than that of conventional engine. Consequently, the provisions of the international emissions standards for diesel engine equipped passenger cars, commercial vehicles, and ships have become more stringent. These standards include the EU Euro 6, the IMO MEPC Tier 3, and the US EPA Tier 4. Ryu et al. published a study that applied fuel additives to two-stroke diesel engines. In this study, a four-stroke diesel engine using diesel oil for a generator is utilized as the test subject, and an experiment is performed to verify whether fuel additive can be used to improve performance and exhaust emissions. In addition, this experimental study presents research results for the application of fuel additives in both two-stroke and four-stroke diesel engines. The experimental results were compared and analyzed by placing an oil-soluble calcium-based organometallic compound in diesel oil. The results confirmed that the addition of fuel additive improved the performance (fuel consumption rate, exhaust gas temperature) and exhaust emissions (NOx, CO) of the diesel engine.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.1-11
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• 1999

The Korean government is developing a systematic plan of integrated coastal management for effective conservation, utilization, and development of coastal areas. For this plan, integrated maps of land maps and nautical charts are indispensable. However, these maps are not made, nor studied yet in terms of integration, although digital maps(DM) on land and electronic nautical charts(ENC) have been recently developed by Korean Geography Institute and National Marine Investigation Institute, respectively. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined, specifically, coastal lines from DM and ENC are matched against each other. Issues on map production procedures, coordinate systems, and map projections, are carefully considered. A test coastal area located in Seo-Gu, Pusan, over 14 km of coastal lines is selected for the edge matching of coastal lines. RMS differences are 13.83 m and 4.37 m over man-made coastal lines and natural coast lines, respectively, which are quite larger considering a scale difference and other factors. However, no systematic differences are found.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.5
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• pp.343-349
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• 2013

Crashworthy fuel cells have a great influence on improving the survivability of crews. Since 1960's, the US army has developed a detailed military specification, MIL-DTL-27422, defining the performance requirements for rotorcraft fuel cells. In the qualification tests required by MIL-DTL-27422, the crash impact test should be conducted to verify the crashworthiness of fuel cell. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. Because the crash impact test itself takes a long-term preparation efforts together with costly fuel cell specimens, the failure of crash impact test can result in serious delay of a entire rotorcraft development. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error with full-scale fuel cells. Present study performs the numerical simulation using SPH(smoothed particle hydro-dynamic) method supported by a crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the resulting equivalent stresses of fuel cell itself are calculated and vulnerable areas are also evaluated.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.145-148
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• 2015

According to the Korea Food Additives Code, sodium metasilicate is permitted for use as a filtering agent for edible oils and fats. Sodium metasilicate is currently used as a food additives to increase the weight of shark fins. In this study, we developed an analytical method to quantify sodium metasilicate in food. Sodium metasilicate content was estimated by measuring the moisture content, pH and silicon content of shark fins. Silicon content was analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES) following microwave-assisted digestion with $HNO_3$ (65%) and $H_2O_2$ (30%). Shark fin total silicon content was $7.17{\pm}8.92mg/kg$, while the soluble silicon content was $2.34{\pm}3.80mg/kg$. After soaking raw shark fin in an aqueous solution of sodium metasilicate, fin weight, pH and silicon content were measured. These results would be used as the basic information for shark fins safety management.

• Geotechnical Engineering
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• v.5 no.1
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• pp.7-18
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• 1989

In pile load tests on end bearing piles, generally, it is not possible to continue loading to the ultimate load. Thus, the concept of yield load has been introduced for determining design loads Iron the pile load test records. The conventional rules to determine the yield load were not available for evaluation on pile load test records obtained in 6 fields nearby westers 8r Southern Coasts in Korea. A new rule 9.as presented to determine easily the yield load, based on investigations on the pile load test records. The yield load of piles is determined at the infiection point on semi-logarithmic coordinates (P-logS), in which load is plotted in normal scale and settlement is plotted in logarithmic scale. This method may not only save much costs and times but also present safe luorking circumstances for pile load tests in field. It was found that the yield load represented the elastic limit of the pile load-settlement behalf.iota. The ultimate load, which is given at 25.4mm settlement on pile head, was 1.5 times of the yield load. The allowable long-term and short-term load capacities were, respectively, 50% and 75% of the yield load. The safety factors to get the allowable pile capacity were obtained as 2.0~4.0 for the equations to predict the static pile capacity.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.227-236
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• 2003

The evaluation of the reliable strength and deformation characteristics of weathered granite masses is very important for the design of geotechnical structure under working stress conditions. Various types of laboratory test such as triaxial compression test can be performed to determine the strength parameters. However, it is very difficult to obtain the representative undisturbed samples on the site and also the rock specimen cannot represent rock mass including discontinuities, fracture zone, etc. This study aims to investigate the strength and deformation characteristics of granite masses corresponding to its weathering and develop a practical strength parameter evaluation method using the results of PMT. To predict weathering intensity and strength parameters of the weathered granite masess in the field, various laboratory tests and in-situ tests including field triaxial test and PMT are carried out. Based on the results of weathering index tests, the classification method is proposed to identify the weathering degree in three groups for the weathered granite masses. Using the analytical method based on the Mohr-Coulomb failure criteria and the cavity expansion theory, the strength parameters of rock masses were evaluated from the results of PMT. It shows that weathering intensity increases with decreasing the strength parameters exponentially. The strength parameters evaluated with the results of PM almost coincide with the results of field triaxial test.

• The Korean Journal of Financial Management
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• v.9 no.2
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• pp.101-147
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• 1992

증권거래소(證券去來所)는 시황에 따라 위탁증거금율(委託證據金率)을 탄력적으로 변경 운용함으로써 시장의 수급을 조절하는 등의 시장관리수단의 하나로 이용하여 공정한 시세형성을 기하고자 설립시부터 증권회사로 하여금 매매의 위탁시 위탁증거금을 징수하도록 규정하고 증거금율을 상황에 따라 신축적으로 운용하여 1962년 이후에만도 무려 32회이상 변경하였다. 따라서 문제의 핵심은 위탁증거금징수가 주식시장에서의 과잉투기행위를 근절시키고 주가변동율(株價變動率)(stock volatility)을 감소시켜 공정거래질서(公正去來秩序)를 확보하는데 기여하고 있는지의 여부가 된다. 이 점은 특히 미국(美國)에서 1987년 10월 소위 '검은 월요일(Black Monday)'당시 갑작스러운 주가폭락과 시장체계의 붕괴사태이후 금융시장의 발전을 모색하는 정책당국자들과 학자들사이에 새로운 주목을 받기 시작하였다. Salinger(1989)와 Schwert(1989)는 위탁증거금율(委託證據金率)의 변경과 주가변동율(株價變動率)의 감소와는 아무런 인과관계가 없다고 결론을 내리고 있다. 특히 Schwert는 거래일시중단시책마저도 주가변동율에 별 효과가 없다고 주장하면서 금융공황과 관련된 거래일시중단은 주가변동을 큰 폭으로 증가시켜왔으나 금융공황을 동반하지 않은 기래일시중단은 높은 주가변동율과 무관함을 밝히고 있다. Hardouvelis(1991)는 그러나 위탁증거금율을 상승시키면 주가변동율이 낮아지며, 결과적으로 주가가 본원적가치(本源的價値)로부터 일탈하는 현상도 줄어든다는 사실을 통계적으로 입증하고, 위탁증거금의 징수가 시장을 교란하는 악성투기행위를 억제시키는데 매우 효과적인 정책수단이라고 주장하고 있다. 본 연구는 우리나라 주식시장에서 과잉투기현상을 억제하여 시장의 안정을 확보하는 기능으로서의 위탁증거금제도에 대해 그 경제적 효과여부를 규명하는 실증분석을 행하였다. 이 논문에서는 Schwert(1989)와 Hardouvelis(1991)의 방법을 원용하여 두가지 서로 다른 방법으로 주가변동율을 측정하여 비교하였다. 통계적 기법은 기본적으로 다변량(多變量) 회귀분석법(回歸分析法)을 택하였다. 분석의 결과로 매우 흥미로운 실증상(實證上)의 규칙성(規則性)을 발견하였다. 즉 현금시장(cash market)의 위탁증거금율이 높아지면 실제주가변동율(實際株價變動率)과 초과주가변동율(超過株價變動率)이 감소되고, 또한 유행(流行)의 경우와 마찬가지로 본원적 가치로부터의 괴리가 작아진다. 이 결과에 따르면 위탁증거금의 징수는 그 제도의 취지에 부합되고 있다. 다만 제도운용상의 이유이거나 혹은 우리나라 주식시장의 투자자들이 비합리적인 투자형태를 보임에 따라 그 정책적 효과는 때로 역기능적인 결과로 초래하였다. 그럼에도 불구하고 이 연구결과를 통하여 최소한 주식시장(株式市場)에서 위탁증거금제도는 그 제도적 의의가 여전히 있다는 사실이 확인되었다. 또한 우리나라 주식시장에서 통상 과열투기 행위가 빈번히 일어나 주식시장을 교란시킴으로써 건전한 투자풍토조성에 저해된다는 저간의 우려가 매우 커왔으나 표본 기간동안에 대하여 실증분석을 한 결과 주식시장 전체적으로 볼 때 주가변동율(株價變動率), 특히 초과주가변동율(超過株價變動率)에 미치는 영향이 그다지 심각한 정도는 아니었으며 오히려 우리나라의 주식시장은 미국시장에 비해 주가가 비교적 안정적인 수준을 유지해 왔다고 볼 수 있다.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.2
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• pp.150-155
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• 2006

This study observes information education of facilities for the disabled. A certain facility for the disabled was selected in Daejeon to compare the educational environment for visually disabled of regular school for visually disabled and facilities for the disabled, and then personnel current situation by age and form of the disabled, teacher current situation by age, computer possessing current situation, weekly education schedule for the disabled, and equipment possessing current situation for visually disabled were observed. As a result, expansion of Braille education was necessary for the Braille skilled, which is the basis of information education information to visually disabled is insufficient, and forming of learning environment was desperate since equipment necessary for computer education was absurdly lacking unlike regular schools. Also, only 10 out of 21 teachers(47%) majored in social welfare or special education, and none majored in computer. It is because support for employment of those who majored social welfare, special education, and computer is insufficient compared to treatment for teachers at general schools at the facility for the disabled since teacher employment regulation at the facility for the disabled is not set. It is studied that providing high-quality of education environment to the disabled was desperate through physical and social treatment that suits nurturing of the professionally knowledge personnel through expansion of equipments and constant education and training based on government support to promote information education of the facility for the disabled.