• 산업경영시스템학회지
• /
• 제40권1호
• /
• pp.95-104
• /
• 2017

This paper deals with solution methods for discrete and multi-valued optimization problems. The objective function of the problem incorporates noise effects generated in case that fitness evaluation is accomplished by computer based experiments such as Monte Carlo simulation or discrete event simulation. Meta heuristics including Genetic Algorithm (GA) and Discrete Particle Swarm Optimization (DPSO) can be used to solve these simulation based multi-valued optimization problems. In applying these population based meta heuristics to simulation based optimization problem, samples size to estimate the expected fitness value of a solution and population (particle) size in a generation (step) should be carefully determined to obtain reliable solutions. Under realistic environment with restriction on available computation time, there exists trade-off between these values. In this paper, the effects of sample and population sizes are analyzed under well-known multi-modal and multi-dimensional test functions with randomly generated noise effects. From the experimental results, it is shown that the performance of DPSO is superior to that of GA. While appropriate determination of population sizes is more important than sample size in GA, appropriate determination of sample size is more important than particle size in DPSO. Especially in DPSO, the solution quality under increasing sample sizes with steps is inferior to constant or decreasing sample sizes with steps. Furthermore, the performance of DPSO is improved when OCBA (Optimal Computing Budget Allocation) is incorporated in selecting the best particle in each step. In applying OCBA in DPSO, smaller value of incremental sample size is preferred to obtain better solutions.

• Nuclear Engineering and Technology
• /
• 제52권8호
• /
• pp.1626-1637
• /
• 2020

This work covers an important point of the benchmark released by the expert group on Uncertainty Analysis in Modeling of Light Water Reactors. This ambitious benchmark aims to determine the uncertainty in light water reactors systems and processes in all stages of calculation, with emphasis on multi-physics (coupled) and multi-scale simulations. The Gesellschaft für Anlagen und Reaktorsicherheit methodology is used to propagate the thermal-hydraulic uncertainty of macroscopic parameters through TRACE5.0p3/PARCSv3.0 coupled code. The main innovative points achieved in this work are i) a new thermal-hydraulic model is developed with a highly-accurate 3D core discretization plus an iterative process is presented to adjust the 3D bypass flow, ii) a control rod insertion occurrence -which data is obtained from a real PWR test- is used as a transient simulation, iii) two approaches are used for the propagation process: maximum response where the uncertainty and sensitivity analysis is performed for the maximum absolute response and index dependent where the uncertainty and sensitivity analysis is performed at each time step, and iv) RESTING MATLAB code is developed to automate the model generation process and, then, propagate the thermal-hydraulic uncertainty. The input uncertainty information is found in related literature or, if not found, defined based on expert judgment. This paper, first, presents the Gesellschaft für Anlagen und Reaktorsicherheit methodology to propagate the uncertainty in thermal-hydraulic macroscopic parameters and, then, shows the results when the methodology is applied to a PWR reactor.

• 한국실내디자인학회논문집
• /
• 제25권4호
• /
• pp.60-67
• /
• 2016

Falls are accidents that can happen throughout the overall period of human life and their results are very fatal and have a serious negative effect on individuals and society. In case of aged people, even though they live in places where dangerous risks of falls are prevalent, they cannot improve their residential environment for themselves. Therefore, this study intends to prove the effects of fall prevention education by providing fall prevention education to spatial design majoring students in order to improve their perception about the falls and fall prevention environments and their social responsibility as a designer. This study was designed as Quasi-experimental study, and 121 beginners to spatial design received the education. As a result, the effects of education was proved by showing improvements on their awareness about the fall risks, the importance of fall prevention environment and social responsibility as a designer. In addition, after the education students could know more about spatial elements for fall prevention and they specified the details of important environmental factors for fall prevention. Generally, fall prevention education has been given to aged people and this is a first example of fall prevention education that was given to younger generation. It is meaningful that fall prevention education has changed the awareness of the students to help them work in spatial environment design with a strong sense of responsibility as an expert of spatial designer in future.

• 정보관리학회지
• /
• 제18권4호
• /
• pp.37-55
• /
• 2001

본 연구에서는 특정 주제분야의 텍스트를 대표할 수 있는 단어술어를 추출하고 기본문형을 형성 한 후 각 단서술어의 기본문형을 실례화하여 연결함으로써 요약문을 작성하는 자동요약시스템의 모형을 설계하고 구현하였다. 시스템은 학습과정과 요약과정을 구분되며, 학습과정에서는 술어와 격조사를 출현빈도를 이용하여 주제분야 텍스트집단을 대표하는 단어술어와 필수격 조사를 추출한 뒤 단어술어가 이루는 문장의 기본문형을 형성한다. 요약과정에서 실례화 규직을 요약 대상 문장의 구문 분석 결과에 적용하여 기본문형의 격조사와 결합될 논항을 찾아 단문을 생성하고 연결하여 요약문을 완성한다. ‘화재’및‘강도’와 관련된 신문기사를 대상으로 실험을 수행하였으며, 작성된 요약문은 단어술어가 포함된 주요 문장에서 추출한 필수 정보항목과 술어를 중심으로 생성된 문장들로서 문장간의 연결이 자연스러울 뿐 아니라 텍스트의 전체적인 의미를 표현할 수 있었다. 또한, 통계적 기법을 이용한 학습을 통해 주제영역의 확장이 가능하였다.

• 대한인간공학회지
• /
• 제25권4호
• /
• pp.51-62
• /
• 2006

The concept of universal design has recently emerged as an important aspect of product design. Universal design is considerably analogous to ergonomic design in a way that it takes the capabilities and limitations of users into consideration during the product development process. However, relatively few studies have been devoted to reflect the practical use of ergonomic principles on universal design. This research attempts to develop a universal design index for mobile phone design to quantify how well a product complies with principles of universal design. The research also emphasizes on ergonomic principles as a basis of evaluation. A generation of the evaluation items was done by cross-checking among the personal, activity and product components. Personal components consist of human characteristics including age, physique, perceptual capacity, life-style, etc. Activity components were derived from those scenarios of mobile phone use while product components were composed of the parts to which a user interacts. Further analysis systematically generated a universal index from relationship matrices among the three components. The index was then used to test its suitability by applying to the evaluation of mobile phones currently on the market. This study demonstrates a development process through which evaluations can be made possible for universal design. The research suggests an improved approach to the appraisal of how well mobile phones are universally designed based on ergonomic principles.

• 한국전자파학회논문지
• /
• 제27권12호
• /
• pp.1097-1104
• /
• 2016

적외선 카메라는 Mil-Std-461 항목 중 복사성 방사 잡음 시험, RE-102의 규격 만족에 어려움을 겪는다. 특히 무인항공기용 전자장비의 경우 차폐 케이블을 사용하지 않아 전자기적합성 규격 만족이 어려워 적절한 대응 설계가 필요하다. 무인정찰기용 적외선 카메라의 RE-102 시험 중 50~200 MHz 대역에서 30 dBuV/m 이상 규격을 초과하는 방사 잡음을 확인하였다. Pcb em scan 결과, 디지털 제어 신호 클록의 체배 주파수에 의한 첨두 잡음 발생을 확인하였고, 카메라의 제어 클록에 3 % 다운 스프레딩 방식의 확산 스펙트럼 클록 생성기를 적용하여 방사 잡음이 최대 22.9 dBuV/m 감소함을 확인하였다.

• Structural Engineering and Mechanics
• /
• 제39권2호
• /
• pp.241-266
• /
• 2011

The Self Compacting Concrete, SCC is the new generation type of concrete which is not needed to be compacted by vibrator and it will be compacted by its own weight. Since SCC is a new innovation and also the high strength self compacting concrete, HSSCC behavior is like a brittle material, therefore, understanding the strength effect on the serviceability performance of reinforced self compacting concretes is critical. For this aim, first the normal and high strength self compacting concrete, NSSCC and HSSCC was designed. Then, the serviceability performance of reinforced connections consisting of NSSCC and HSSCC were investigated. Twelve reinforced concrete connections (L = 3 m, b = 0.15 m, h = 0.3 m) were simulated, by this concretes, the maximum and minimum reinforcement ratios ${\rho}$ and ${\rho}^{\prime}$ (percentage of tensile and compressive steel reinforcement) are in accordance with the provision of the ACI-05 for conventional RC structures. This study was limited to the case of bending without axial load, utilizing simple connections loaded at mid span through a stub (b = 0.15 m, h = 0.3 m, L = 0.3 m) to simulate a beam-column connection. During the test, concrete and steel strains, deflections and crack widths were measured at different locations along each member. Based on the experimental readings and observations, the cracked moment of inertia ($I_{cr}$) of members was determined and the results were compared with some selective theoretical methods. Also, the flexural crack widths of the members were measured and the applicability for conventional vibrated concrete, as for ACI, BS and CSA code, was verified for SCCs members tested. A comparison between two Codes (ACI and CSA) for the theoretical values cracking moment is indicate that, irrespective of the concrete strength, for the specimens reported, the prediction values of two codes are almost equale. The experimental cracked moment of inertia $(I_{cr})_{\exp}$ is lower than its theoretical $(I_{cr})_{th}$ values, and therefore theoretically it is overestimated. Also, a general conclusion is that, by increasing the percentage of ${\rho}$, the value of $I_{cr}$ is increased.

• 한국정보통신학회논문지
• /
• 제25권11호
• /
• pp.1531-1537
• /
• 2021

게임의 품질은 재미와 기능의 안정성으로 평가될 수 있다. 이 가운데 재미에 대한 품질 영역은 게임의 본질이므로 게임 디자이너의 입장에서는 아주 중요하게 고려해야 될 요소이다. 독창성과 몰입성이 높은 재미있는 게임 디자인은 대개 아이디어 도출, 컨셉 설정과 같은 개발 초기 단계에서 이루어진다. 이 때 게임의 재미요소 검증이 가능하도록 하는 것은 게임의 성공에 중요한 영향을 미친다. 본 연구에서는 게임 디자인 공부를 시작하는 학생들에게 재미요소 설계를 교육할 때 PIT기법을 활용한 사례를 소개하고 그 효과를 분석하였다. 고품질의 재미있는 게임 디자인을 위해 PIT기법이 게임 디자인 교육현장에서 더 활발하게 사용되기를 기대한다.

• 토지주택연구
• /
• 제14권2호
• /
• pp.137-145
• /
• 2023

본 연구에서는 매립석탄재를 이용한 CLSM의 실질적인 기술개발의 일환으로 매립석탄재의 입도분포 및 미립자 함량 등 물성에 따른 CLSM의 유동성, 블리딩 속도, 강도 등의 특성을 검토하였다. 그 결과 채취한 매립석탄재는 밀도 특성과 입도 분포가 다른 것으로 나타났으며 비산재의 양이 많고 혼합수를 많이 첨가한 시편의 경우 블리딩 비율이 기준을 만족하지 못하였고 압축강도 시험 결과, 4시간 동안 0.5MPa 이상의 강도발현은 단위결합재량이 200 이상인 반수석고를 사용한 시편의 경우 만족스러운 것으로 나타났다. 나머지 석고는 강도발현이 불량한 것으로 나타나 매립석탄재는 CLSM 소재로 활용이 가능할 것으로 판단되나 각 발전사의 회처리장에 매립된 석탄재의 물리화학적 특성을 규명하고 적용할 필요가 있다.

• 한국컴퓨터정보학회논문지
• /
• 제28권10호
• /
• pp.103-111
• /
• 2023

산악지대, 특히 오픈스페이스에서의 보행은 산악지형을 기반으로 이루어지는 특수 활동영역에서 중요하다. 그러나 최근의 보행 경로 연구는 보행자와 환경 요소를 포괄적으로 네트워크 분석에 포함시키지만, 주로 한정된 공간을 대상으로 하며 산악지형 등, 데이터가 부족한 지형은 분석 대상에서 제외된다. 본 논문에서는 산악지형의 오픈스페이스에서 그물망 기반의 가상 보행 네트워크를 만들며, 경사도를 반영한 산악 보행 경로 생성 방법을 제안한다. 이 방법은 거리측정에 경사도를 고려하여 실제 지형을 더 잘 반영하며, 기존 경로 분석 서비스에서 제공하지 않는 오픈스페이스를 이용한 산악 보행 경로를 제시하고, 시험을 통해 이를 입증하였다. 본 논문의 설계 방법은 조난, 산악구조, 전술 훈련 등에서 산악지형의 오픈스페이스를 포함한 경로 생성 방법으로 활용될 수 있을 것으로 기대한다.