• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4114-4114
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• 2001

For the quality control of tablets several parameters have to be checked. The most important one is the content of an active ingredient which has to match a narrow range around the designated content. The only useful measurement mode is transmission which provides information of the complete tablet. A measurement in diffuse reflectance would register only the surface which is useless especially in case of a coated tablet. In this work tablets for a clinical study (placebo/verum studies) with very low concentrations of the active ingredient were measured. The concentration range was 0 to 6 mg with a total weight of the tablets of 105 mg, leading to a highest concentration of the active component of 5.7% by weight. Especially the spectroscopic distinction between the placebo and the low dosage forms with 0.25 and 0.5 mg active agent requires an extraordinarily accurate sampling technique. Using the VECTOR 22/N-T in transmission mode allows the collection of the information from the complete tablets. A quantitative PLS-model with transmission spectra from the tablets described above shows that the active substance can be predicted with a RMSECV (root mean square error of cross validation) of 0.04% absolute for this special application. The results are compared with those of measurements in diffuse reflectance using different accessories.

• Steel and Composite Structures
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• 제22권2호
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• pp.235-255
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• 2016

This paper experimentally investigated the behavior of steel frame structures of traditional-style buildings subjected to combined constant axial load and reversed lateral cyclic loading conditions. The low cyclic reversed loading test was carried out on a 1/2 model of a traditional-style steel frame. The failure process and failure mode of the structure were observed. The mechanical behaviors of the steel frame, including hysteretic behaviors, order of plastic hinges, load-displacement curve, characteristic loads and corresponding displacements, ductility, energy dissipation capacity, and stiffness degradation were analyzed. Test results showed that the Dou-Gong component (a special construct in traditional-style buildings) in steel frame structures acted as the first seismic line under the action of horizontal loads, the plastic hinges at the beam end developed sufficiently and satisfied the Chinese Seismic Design Principle of "strong columns-weak beams, strong joints-weak members". The pinching phenomenon of hysteretic loops occurred and it changed into Z-shape, indicating shear-slip property. The stiffness degradation of the structure was significant at the early stage of the loading. When failure, the ultimate elastic-plastic interlayer displacement angle was 1/20, which indicated high collapse resistance capacity of the steel frame. Furthermore, the finite element analysis was conducted to simulate the behavior of traditional-style frame structure. Test results agreed well with the results of the finite element analysis.

• 한국농공학회논문집
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• 제53권6호
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• pp.31-41
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• 2011

This study was conducted to predict future land-cover changes under climate change scenarios and to cluster analysis of regional land-cover characteristics. To simulate the future land-cover according to climate change scenarios - A1B, A2, and B1 of the Special Report on Emissions Scenarios (SRES), Dyna-CLUE (Conversion of Land Use Change and its Effects) was applied for modeling of competition among land-use types in relation with socioeconomic and biophysical driving factors. Gyeonggi-do were selected as study areas. The simulation results from 2010 to 2040 suggested future land-cover changes under the scenario conditions. All scenarios resulted in a gradual decrease in paddy area, while upland area continuously increased. A1B scenario showed the highest increase in built-up area, but all scenarios showed only slight changes in forest area. As a result of cluster analysis with the land-cover component scores, 31 si/gun in Gyeonggi-do were classified into three clusters. This approach is expected to be useful for evaluating and simulating land-use changes in relation to development constraints and scenarios. The results could be used as fundamental basis for providing policy direction by considering regional land-cover characteristics.

• 한국전자통신학회논문지
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• 제1권1호
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• pp.87-93
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• 2006

이 논문은 블루투스 장치의 전 세계적으로 사용되는 무허가 ISM 대역의 2.4GHZ로 동작한다. 이 대역은 널리 사용되고 있지만, 블루투스 이외의 수많은 다른 시스템들이 이 주파수대를 사용하고 있고 마이크 웨이브 오븐과 같은 잡음원이 이 주파수대를 차지하고 있기 때문에 오히려 방해가 심한 주파수 대역이 되고 있다. 블루투스는 이와 같이 방해가 심한 전파환경을 극복하기 위해 빠른 주파수 호핑법과, 에러방지 및 정정기술을 사용하고 있다. 이와 같은 상황에도 불구하고, 저가의 블루투스 시스템이 신뢰성 있고 안정하게 하기 위해 언급할 몇 가지 중요한 설계 상 문제점이 있고 시스템 설계시 몇 가지 면밀한 주의가 필요하므로 연구하고자 한다.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.8-16
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• 2021

The tourism industry is influenced by a large number of factors that affect the development scenarios of the tourism in different ways. At the same time, tourism is an important component of the national economy of any state, forms its image, investment attractiveness, is a source of income and a stimulus for business development. The aim of the article is to conduct an empirical study to identify the importance of cognitive determinants in the development of tourism. The study used general and special methods: systems analysis, synthesis, grouping, systematization, cognitive modeling, cognitive map, pulse method, predictive extrapolation. Target factors, indicators, and control factors influencing the development of tourism in Ukraine are determined and a cognitive model is built, which graphically reflects the nature of the influence of these factors. Four main scenarios of the Ukrainian tourism industry are established on the basis of creating a matrix of adjacency of an oriented graph and forecast modeling based on a scenario approach. The practical significance of the obtained results lies in the possibility of their use to forecast the prospects of tourism development in Ukraine, the definition of state policy to support the industry that will promote international and domestic tourism.

• 산업진흥연구
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• 제8권2호
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• pp.177-185
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• 2023

최근 물류기업은 경제활동의 중요한 구성요소로 빠르게 발전해 왔으나 물류기업의 특수한 성과관리 방식으로 인해 성과평가에 문제가 대두되고 있다. 본 논문은 중국 내 19개 상장 물류기업의 경영성과를 분석하여 실적개선 전략을 제시하였다. 투입변수로는 운영비, 연구개발비, 인건비, 일반관리비를, 산출변수로는 영업이익과 순이익을 채택하였다. DEAP 2.1 소프트웨어를 사용하여 2016년부터 2021년까지 BBC 모델에 의해 DEA 효율성을 평가하였다. 연도별 경영실적을 분석한 결과 일부 상장 물류기업이 안정적이고 전향적인 성과 결과를 보이고 있었다.

• 정보처리학회논문지A
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• 제10A권3호
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• pp.269-278
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• 2003

웹 기반 교육의 대중화로 학습 보조 도구를 이용한 다양한 웹 학습 방법들이 제시되고 있으며 또한 이틀 시스템의 운용 환경, 컨텐츠명세 그리고 활용 등의 상호 운용성 지원을 위한 표준화에 대한 연구가 국제표준기관 등을 통해 활발히 이루어지고 있다. 특히 e-learning 개발 환경을 위한 Learning Technology Standard Architecture(LTSA)를 기능별 5계층을 IEEK에서 제정하였다. 이 LTSA의 학습 보조 도구 표준화 영역에서 학습과정 피드백을 제공하는 질의 응답 학습 방법에 대한 표준규약기능을 명세하지 않고 있다. 본 논문에서는 국제표준화 기술인 ITSA 시스템 구성중 제 3계층을 기반한 질의 응답 학습 도구에 대해 연구한다. 데이터 중심으로 작성된 LTSA 컴포넌트를 객체지향 또는 컴포넌트 패라다임으로 재 정의하는 모델을 제안하고 기존의 Loaming Object Meatdata(LOM)을 참조하여 질의 응답 메타 데이터인 Query Answer Metadata(QAM)를 서술한다. 이들 재정의 모델과 QAM을 통합한 Query Answer Learning Tool(QALT)를 분석, 설계하여 프로토타이핑시스템으로 구현한다. 이를 통해 웹 기반 교육의 효율성 및 관련 도구 개발의 품질 및 생산성 효율을 가진다.

• Steel and Composite Structures
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• 제18권6호
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• pp.1423-1450
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• 2015

The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.

• Structural Engineering and Mechanics
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• 제65권3호
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• pp.291-302
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• 2018

Rigid body spring method (RBSM) is an effective tool to simulate the cracking process of structures, and has been successfully applied to investigate the behavior of reinforced concrete (RC) members. However, the theoretical researches and engineering applications of this method mainly focus on two-dimensional problems as yet, which greatly limits its applications in actual engineering projects. In this study, a three-dimensional (3-D) RBSM for RC structures is proposed. In the proposed model, concrete, reinforcing steels, and their interfaces are represented as discrete entities. Concrete is partitioned into a collection of rigid blocks and a uniform distribution of normal and tangential springs is defined along their boundaries to reflect its material properties. Reinforcement is modeled as a series of bar elements which can be freely positioned in the structural domain and irrespective of the mesh geometry of concrete. The bond-slip characteristics between reinforcing steel and concrete are also considered by introducing special linkage elements. The applicability and effectiveness of the proposed method is firstly confirmed by an elastic T-shape beam, and then it is applied to analyze the failure processes of a Z-type component under direct shear loading and a RC beam under two-point loading.

• 한국가스학회지
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• 제1권1호
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• pp.27-32
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• 1997

화학 공정을 계속적으로 감시함으로써 공정의 이상이 장치의 고장 또는 폭발에 이르지 않도록 조기에 이상을 감시하는 기술은 공장 조업의 안정성과 생산성의 측면에서 볼 때 매우 중요하다 최근, DCS와 같은 공정 정보 시스템이 널리 보급됨에 따라서 방대한 양의 데이터들을 해석해서 실시간으로 공정을 감시하고 진단할 수 있는 기반이 마련되었다. 본 연구에서는 계층적 분해 기법과 PCA에 기반을 둔 공장 규모의 실시간 감시 기법을 제안한다. 대형 공정을 효율적으로 모니터링 하기 위하여 전체 공정은 몇 개의 군으로 나뉘며 또한 이 군은 다시 몇 개의 하위 군으로 세분하게 된다. 이렇게 전체 공정을 분해하여 계층적인 공정 모델을 구성함으로써, 전체 공정의 조업 상황을 감시할 수 있을 뿐만 아니라 이상이 발생했을 시에는 하위 계층의 조업 상황을 고려하여 보다 자세한 이상 원인을 진단할 수 있다. 또한 각 세부 단위 공정들에 대한 조업 정보를 포함하고 있는 하위 모델들과 전체 조업 전반에 관한 정보를 지닌 전체 모델을 통하여 공정 이상을 조기에 감시함으로써 이상이 전파를 방지할 수 있다. 이러한 실시간 감시 및 진단 기법을 구현학 Idnl하여 기존의 SPC와 다변량 통계 기법의 하나인 PCA를 적용하였으며, 제안한 방법의 감시 및 진단 성능을 평가하기 위하여 41개의 측정 변수를 가진 Tennessee Eastman 공정에 대하여 전산 모사를 수행하였다. 세 가지 경우에 대하여 적용한 결과들은 이상의 신속한 감지와 믿을만한 원인 진단 능력을 보여 주었다.