• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.959-964
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• 2010

In this work, equilibrium molecular dynamics (MD) simulations in a microcanonical ensemble are performed to evaluate the friction coefficient of a Brownian particle (BP) in a Lennard-Jones (LJ) solvent. The friction coefficients are determined from the time dependent friction coefficients and the momentum autocorrelation functions of the BP with its infinite mass at various ratios of LJ size parameters of the BP and solvent, ${\sigma}_B/{\sigma}_s$. The determination of the friction coefficients from the decay rates of the momentum autocorrelation functions and from the slopes of the time dependent friction coefficients is difficult due to the fast decay rates of the correlation functions in the momentum-conserved MD simulation and due to the scaling of the slope as 1/N (N: the number of the solvent particle), respectively. On the other hand, the friction coefficient can be determined correctly from the time dependent friction coefficient by measuring the extrapolation of its long time decay to t=0 and also from the decay rate of the momentum autocorrelation function, which is obtained by time integration of the time dependent friction coefficient. It is found that while the friction coefficient increases quadratically with the ratio of ${\sigma}_B/{\sigma}_s$ for all ${\sigma}_B$, for a given ${\sigma}_s$ the friction coefficient increases linearly with ${\sigma}_B$.

• 농업과학연구
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• 제26권2호
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• pp.70-76
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• 1999

Rice farming is not only the most important income resources of Korean farmers but also the roots of Korean traditional culture. Paddy fields have acted as an food supply base but also have contributed to the public multi-functions such as flood control, water conservation, controlling soil erosion, providing recreational and resting spaces, water purification, air cleaning, oxygen supply and air cooling and so on. The public multi-functions of paddy except rice production have not been evaluated before UR negotiation and starting WTO system. Under the drastic changes of rice economic settings as price decrease of rice and downward decrease of farm income, Korean and Japanese farmers might have lost their intention to grow rice in paddy fields without the direct payment system to compensate rice income decrease. To adapt the direct payment system, the total public value of multi-function of paddy should be identified in terms of money. According to the research results, the total value of multi-functional value of paddy in Korea were estimated 21,596thousand won which is higher than rice production value by 2.1 times. On the other hand the total value of Japanese paddy were amounted to 21,390 Yen which is more than that of Korea by 10times outstandingly. Likewise Japanese have evaluated the paddy field very important enterprise from the view point of food security and multi -functions of paddy to their socio-economic life and environmental sustainability in Japan.

• Smart Structures and Systems
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• 제11권4호
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• pp.365-386
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• 2013

Monitoring systems currently applied to concrete bridges include strain gauges, inclinometers, accelerometers and displacement transducers. In general, vertical displacements are one of the parameters that more often need to be assessed because their information reflects the overall response of the bridge span. However, the implementation of systems to continuously and directly observe vertical displacements is known to be difficult. On the other hand, strain gauges and inclinometers are easier to install, but their measurements provide no more than indirect information regarding the bridge deflection. In this context, taking advantage of the information collected through strain gauges and inclinometers, and the processing capabilities of current computers, a procedure to evaluate bridge girder deflections based on polynomial functions is presented. The procedure has been implemented in an existing software system - MENSUSMONITOR -, improving the flexibility in the data handling and enabling faster data processing by means of real time visualization capabilities. Benefiting from these features, a comprehensive analysis aiming at assessing the suitability of polynomial functions as an approximate solution for deflection curves, is presented. The effect of boundary conditions and the influence of the order of the polynomial functions on the accuracy of results are discussed. Some recommendations for further instrumentation plans are provided based on the results of the present analysis. This work is supported throughout by monitoring data collected from a laboratory beam model and two full-scale bridges.

• 한국통신학회논문지
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• 제34권6B호
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• pp.630-640
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• 2009

본 논문에서는 고성능 모바일 TFT LCD/OLED 모듈(이하, 모듈)을 위한 헨드헬드 검사장비를 제안한다. 기존 모듈 검사장비는 명멸현상을 구분하기 위해선 동영상 데이터를 모듈에 출력시켜 구분할 수 있으나, 저속 시스템으로는 불가능하다. 또한 기존 검사장치는 저속의 CPU와 FPGA 시스템에서 필요한 몇 가지의 기능을 IP로 설계하고 사용하기 때문에 시스템의 한계를 지니고 있다. 이에 제안한 시스템은 고성능 모바일 모듈을 위한 검사장비로 다양한 크기의 모듈을 H/W나 FPGA의 설계 변경 없이 검사 장비를 휴대하여 여러 가지 부가기능들을 동시에 확인할 수 있다. 시스템은 크게 헨드헬드 검사장비와 내장된 테스터 소프트웨어, 정밀 분석을 위한 PC기반의 소프트웨어로 구성되며, USB 인터페이스 하여 헨드헬드 검사장비의 모든 모듈 테스트 내용을 확인, 저장, 출력 할 수 있도록 설계되어 있다. 제안된 시스템의 유효성 검증은 현장에서 사용하는 9가지의 대표 항목으로 설정하여, 고성능 모바일 TFT LCD/OLED에서 중요한 명멸현상에 대한 풀 프레임 동영상 구동시 별도의 모듈 없이 확인이 가능하였고, 기타 스캔타임 설정, 감마설정, 레지스터 변경, 인터페이스 지원, 다 인치 모듈지원 등이 가능하였다.

• 대한기계학회논문집A
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• 제36권12호
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• pp.1497-1502
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• 2012

복잡한 구조와 다채로운 기능을 수행하는 사람 손의 기능을 모사하는 로봇 손을 제작함에 있어서 유연성 있는 구동기와 센서의 개발이 필수적으로 요구되고 있다. 본 논문에서는 전기활성 고분자를 기반으로 하여 로봇 손에 사용될 수 있는 구동기와 슬립센서의 설계, 제작 및 성능검증에 대한 내용을 소개한다. 전기활성 고분자는 필름형태로 제작되며 양단에 전압을 가하여 수축과 팽창에 따른 움직임이 발생하게 한다. 이와 반대로 전기활성 고분자에 외부의 압력으로 인해 두께나 면적의 변화가 발생하게 되면 정전용량의 변화가 발생하게 된다. 이러한 에너지의 변화소자를 이용하여 구동기와 센서로 이용하였다. 본 논문에서는 전기활성 고분자를 이용한 구동기와 센서를 제시하고 성능평가를 통해 새로운 로봇 손용 에너지 변환 소자로서의 가능성을 연구하였다.

• The Journal of Korean Physical Therapy
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• 제24권5호
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• pp.362-369
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• 2012

Purpose: This study examined the effects of an elastic band resistance exercise program on the body functions and Glycosylated hemoglobin (HbA1c) of elderly people with type 2 diabetes. Methods: Twenty-seven elderly patients with type 2 diabetes were enrolled in this study (exercise group 14, control group 13). The subjects in the exercise group participated in the program for 60 minutes a day, three times a week, for 12 weeks. All the subject's body functions, HbA1c were measured to compare the following: before the intervention, at the completion of the 12 weeks intervention, and eight weeks after the intervention. Results: Compared to the control group, the exercise group showed significant improvements in the 12 week and follow-up measurement after the intervention in body function, such as the strength of the upper and lower limbs, agility and limit of stability. The body functions of the exercise group improved as the period of intervention progressed. On the other hand, the HbA1c level at each follow-up measurement was similar in the two groups. Conclusion: The 12 week elastic band exercise program is recommended as an effective intervention for improving the body functions of elderly people with type 2 diabetes. Nevertheless, a combined intervention of steady exercise, diet therapy and drug therapy will be needed for further active prevention and management of type 2 diabetes.

• 대한안전경영과학회지
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• 제15권1호
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• pp.11-19
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• 2013

In modern systems design and development, one of the key issues is considered to be related with how to reflect faithfully the stakeholder requirements including customer requirements therein, thereby successfully implementing the system functions derived from the requirements. On the other hand, the issue of safety management is also becoming greatly important these days, particularly in the operational phase of the systems under development. An approach to safety management can be based on the use of the failure mode effect and analysis (FMEA), which has been a core method adopted in automotive industry to reduce the potential failure. The fact that a successful development of cars needs to consider both the complexity and failure throughout the whole life cycle calls for the necessity of applying the systems engineering (SE) process. To meet such a need, in this paper a method of FMEA is developed based on the SE concept. To do so, a process model is derived first in order to identify the required activities that must be satisfied in automotive design while reducing the possibility of failure. Specifically, the stakeholder requirements were analyzed first to derive a set of functions, which subsequentially leads to the task of identifying necessary HW/SW components. Then the derived functions were allocated to appropriate HW/SW components. During this design process, the traceability between the functions and HW/SW components were generated. The traceability can play a key role when FMEA is performed to predict the potential failure that can be described with the routes from the components through the linked functions. As a case study, the developed process model has been applied in a project carried out in practice. The results turned out to demonstrate the usefulness of the approach.

• 혜화의학회지
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• 제19권1호
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• pp.25-34
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• 2010

Background : The human being and the bacteria have accomplished a balance and have coexisted each other during long time. Probiotics have evolved with the human host to exist and the result they have operated profitably to human host. So it requires that the functions of probiotics are expounded in view of Traditional Korean Medicine. Aim : Suggest the functions of probiotics in view of Traditional Korean Medicine. Method : The author's research has been performed to review the related references. Results : Probiotics assist the absorption of the lactose, proteins and minerals and product several kinds of vitamins, organic acids. Probiotics suppresses the growth of noxious bacteria and the production of harmful substances or gases. They absorbed and discharge the bile acid, and thus help us maintain the optimal level of blood cholesterol concentration. They can reinforce the immune response of the mucous membrane and control the hypersensitivity immune reaction such as asthma, atopy on the other hand. Probiotics have right functions as above and so can be applied widely in treatment of various disease and symptom. Conclusion : Considering the functions of probiotics in view of Traditional Korean Medicine, they participate in our spleen-earth-system (digestion and synthesis) and liver-wood-system (regulation of digestion, metabolism, internal secretion etc.), assist the function of lung-metal system(respiration and regulation of water metabolism) and regulate wi-chi (reinforce/control immune system). Consequently, hereafter there would be a necessity of control a circumstance in treatment of various diseases under these categories that probiotics should be able to do their right functions inside the human body.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권1호
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• pp.1-15
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• 2023

The aim of this study is to identify intelligent learning support functions in Learning Management System (LMS) to support university student learning activities during the transition from face-to-face classes to online learning. To accomplish this, we investigated the perceptions of students on the levels of importance and urgency toward learning support functions of LMS powered with Artificial Intelligent (AI) technology and analyzed the differences in perception according to student characteristics. As a result of this study, the function that students considered to be the most important and felt an urgent need to adopt was to give automated grading and feedback for their writing assignments. The functions with the next highest score in importance and urgency were related to receiving customized feedback and help on task performance processed as well as results in the learning progress. In addition, students view a function to receive customized feedback according to their own learning plan and progress and to receive suggestions for improvement by diagnosing their strengths and weaknesses to be both vitally important and urgently needed. On the other hand, the learning support function of LMS, which was ranked as low importance and urgency, was a function that analyzed the interaction between professors and students and between fellow students. It is expected that the results of this student needs analysis will be helpful in deriving the contents of learning support functions that should be developed as well as providing basic information for prioritizing when applying AI technology to implement learner-centered LMS in the future.

• 대한수학회보
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• 제42권4호
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• pp.789-805
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• 2005

In this paper we consider analogous of Gronwall-type inequalities involving iterated integrals in the inequality (1.2) for functions when the function u in the right-hand side of the in­equality (1.2) is replaced by the function $u^P$ for some p. These inequalities are effective tools in the study of a system of an integral equation. We also provide some integral inequalities involving iterated integrals.