• 한국IT서비스학회지
• /
• 제3권1호
• /
• pp.21-41
• /
• 2004

The technical proposal suggested and published by MIC(Ministry of Information and Communication, henceforth MIC) contains too general assessment elements, which causes qualitative and subjective assessment of technical proposals. Thus, in terms of the technical proposal assessment. It lacks In fairness, validity and accuracy. Furthermore, it has a great deal of difficulty in assessment caused by the inconsistency between proposal planning and assessment methods. Also, each company has different writing format, so it is impossible to make use of its maneuvering data for the assessment. To overcome these weaknesses, our research focused on a quantitative evaluation on development organization, which is a part of organizational and administrative part of the technical proposal suggested and published by MIC. In this research, we divided development organization for the technical proposal into organization, teams, and team members, and then studied addition, deletion and merging for the assessment criteria. For the related study, we chose especially CMM(Capability Maturity Model) from a lot of international and national references, which is a model measuring the maturity of organization, and then we focused on Small-CMM which is available in the small-sized organization. We also suggested input form, description method, assessment elements for the quantitative assessment in the chosen developmental organization, and finally we proposed standard referencing criteria for the assessment. Our study concludes that our assessment method are valid and available in comparison with the previous Delphi method through a validity evaluation test.

• 한국태양에너지학회 논문집
• /
• 제34권5호
• /
• pp.1-9
• /
• 2014

Daylight is very useful to control the indoor environment, and can save energy in buildings. So it is necessary to evaluate the daylighting performance of buildings. We proposed a simplified equation that can be used in the early stages of design. And we verified the equation by using the measured illuminance data from the 1/5 scale model. We compared the calculated indoor illuminances and measured illuminance including Daylight Factors of scale model in order to verify the applicability of the simplified equation, and proved the analyzed values are acceptable. When we have a target value of the Daylight Factor, we just have to determine the window area, transmittance of the glazing system, and indoor surface reflectance, then can achieve it with this simplified equation.

• 정보교육학회논문지
• /
• 제13권1호
• /
• pp.96-104
• /
• 2009

인터넷 환경에서 이러닝 시스템과 같은 고신뢰성의 정보를 원한다. 인터넷 시스템에서 프로그램과 데이터의 결함이 발생할 수 있기 때문에 신뢰성 분석이 매우 어렵다. 이 논문에서는 인터넷 환경에서 프로그램 신뢰성을 예측하기 위해서 유색 패트리넷 모델을 이용하는 신뢰도 예측 모델을 제안한다. 제안한 모델에 적용하는 신뢰도 분석 절차는 다음과 같다. 먼저, 인터넷 프로그램 모델을 만든다. 이를 유색 패트리넷으로 변환한 후 인터넷 시스템 모델의 신뢰도를 예측한다. 이 방법은 신뢰성 있는 인터넷 프로그램을 개발하는 데 도움을 줄 수 있고, 신뢰도 예측 방법이 매우 간단하기 때문에 적용하기 편리하다.

• Journal of Mechanical Science and Technology
• /
• 제20권6호
• /
• pp.864-873
• /
• 2006

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

• 드라이브 ㆍ 컨트롤
• /
• 제17권4호
• /
• pp.113-124
• /
• 2020

Most of the work of construction equipment and agricultural machinery is done in off-road conditions. Autonomous driving required in these conditions uses GPS sensors, and PID controllers to control their speed and position. The hydrostatic steering, which is composed of a PSU, hydraulic hoses, and cylinders, rather than a mechanical coupling is used in these equipments. The PSU plays a key role in hydrostatic steering. Precise control of the position under various conditions requires detailed behavioral analysis of the basic components and operation. Two Gerotor PSU is now a commonly used safer option. The components of the PSU can be divided into mechanical and hydraulic actuating elements by its behavior. Since the system is combined by mechanical and hydraulic elements, the modelings are performed using Amesim, which is one of the most effective for the multi-domain dynamic system analysis. To confirm the validity of the model, input torque and pressures are checked with varying steering speed. The opening and the steering speed of normal and newly designed control valve set is investigated with the effect of centering spring force and friction. Finally, simulation results with fully detailed model with two gerotors are analyzed and compared with simple model.

• Korean Journal of Acupuncture
• /
• 제35권3호
• /
• pp.149-158
• /
• 2018

Objectives : In this study, we quantitatively evaluated the needle forces using needle insertion-measurement system and compared the needle sensation of each acupuncture practical model. Methods : After inserting acupuncture with a sensor to six models, a lifting-thrusting motion was implemented using the needle insertion-measurement system. The needle force was measured repeatedly, and the measurement was analyzed based on the modified Karnopp friction model for a comparison of friction coefficients. After the insertion, practitioners did lifting-thrusting manipulations. They quantified the similarity of needle sensation with VAS (Visual Analogue Scale). Results : When friction force and coefficients of friction in five different models were compared with a porcine shank model, all five models were significantly different from a porcine shank model, cotton and apple showing the closest frictional values to that of a porcine shank model. In the Cp and Cn values of cotton and in the Cp values of IM injection pad, there was no statistically significant difference. The similarity of the needle sensation between the porcine shank and five models was the highest in the apple, and overlapping papers was the lowest. Conclusions : This study quantitatively compared the physical forces in the practical model when implementing lifting-thrusting manipulations, using a needle insertion-measurement system. We suggest that a reproducible exercise model that reflects the characteristics of various human tissues, such as viscoelasticity or strength, needs to be further developed. This will contribute to establishing standardized acupuncture practice training.

• 대한치과기공학회지
• /
• 제40권1호
• /
• pp.41-47
• /
• 2018

Purpose: The purpose of this study was to analyze the biomechanical properties of the dental implants on the supporting bone using three-dimensional finite element method when three different abutment materials were applied to the implant system. Methods: Three different dental implant models were fabricated by applying Ti, PEEK, and CRE-PEEK (60% carbon-reinforced PEEK) to abutment material. The abutment and connecting screw from the fixture was applied with a tightening torque of 20 Ncm. And then, total loads of 150 N were applied in an $30^{\circ}oblique$ direction (to the vertical). The structural stability of dental implants on the supporting bone was analyzed using Von Mises stress and principal stress values. Results: The maximum tensile stress of the cortical bone was highest at 12.6 MPa in the PEEK abutment (Model-B). Ti abutment (Model-A) and CRE-PEEK abutment (Model-C) showed similar stress distributions (10.6 and 10.3 MPa, respectively). And the maximum compressive principal stress was similar in all models. The Von Mises stress value delivered to the bone around the implant was highest at 16.5 MPa in Model-B. On the other hand, Model-A and C showed similar stress distributions (14.0 and 13.8 MPa, respectively). In addition, the maximum equivalent stress applied to the abutment was highest at 629.8 MPa in Model-A. The stress distribution in Model-C was 573.9 MPa. Whereas, Model-B showed the lowest value at 165.6 MPa. Conclusion : The dental implant supporting bone system using PEEK material seems to have the possibility of supporting bone fracture. It was found that the CRE-PEEK abutment can reduce the elastic deformation and reduce the stress value of the interfacial bone.

• Journal of Advanced Marine Engineering and Technology
• /
• 제34권1호
• /
• pp.102-108
• /
• 2010

본 연구에서는 설계사양과 경제성을 고려한 퍼지형 자동조타기를 설계하기 위한 이전 단계로 Bech와 Wagner Smith의 Nomoto 2차 비선형 확장모델을 퍼지모델로 구현하는 것을 다룬다. 우선 퍼지형 자동조타기를 얻기 위해 선박의 동적 특성을 효과적으로 표현 가능한 T-S 퍼지모델을 얻는다. T-S 퍼지모델은 선박의 회두각속도를 설계변수로 간주하고 이것의 변화에 따라 다수개의 지역 선형모델(서브시스템)을 구한 후, "IF-THEN" 퍼지규칙으로 결합한 것이다. 이때 선형모델의 파라미터와 퍼지모델의 소속함수는 선박의 동적인 특성과 일치하도록 입 출력 데이터와 실수코딩 유전알고리즘이 결합된 모델 조정기법을 이용하여 최적으로 추정한다.

• Journal of Information Processing Systems
• /
• 제3권1호
• /
• pp.1-7
• /
• 2007

In mobile ad hoc networks, an application scenario requires mostly collaborative mobility behavior. The key problem of those applications is scalability with regard to the number of multicast members as well as the number of the multicast group. To enhance scalability with group mobility, we have proposed a multicast protocol based on a new framework for hierarchical multicasting that is suitable for the group mobility model in MANET. The key design goal of this protocol is to solve the problem of reflecting the node's mobility in the overlay multicast tree, the efficient data delivery within the sub-group with group mobility support, and the scalability problem for the large multicast group size. The results obtained through simulations show that our approach supports scalability and efficient data transmission utilizing the characteristic of group mobility.

• 한국정보교육학회:학술대회논문집
• /
• 한국정보교육학회 2006년도 동계학술대회
• /
• pp.107-112
• /
• 2006

본 연구는 인지적 학습효과가 높아지고 자아 존중감과 협동심을 키울 수 있는 JigsawIII모형을 ICT 소양교육에 적용하는 방안에 대한 연구이다. JigsawIII를 토대로 ICT 소양교육의 이론과 기능분야를 학습하도록 학습환경과 학습절차를 구성하고 실제 현장에 적용하여 실험집단에 JigsawIII 모형을 실시하고, 통제집단에 전통학습방법을 실시하였다. 연구의 결과 이론 학습에서는 실험집단과 통제집단의 학습효과가 비슷하였으나, 기능학습에서는 JigsawIII를 적용한 실험집단이 평균점수의 검증결과가 더 높게 나타났으며, 통계적으로도 p<.05 수준에서 유의미한 것으로 나타났다. ICT 소양교육이 실생활에서 응용할 수 있는 ICT 지식을 익히고 능동적으로 활용하도록 하는 것에 그 목적이 있으므로 JigsawIII모형 ICT 교육에 활용한다면 긍정적인 교육적 효과를 이루어낼 수 있을 것이다.