• Korean Management Science Review
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• v.17 no.2
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• pp.39-54
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• 2000

This paper presents a causal forecasting model using guided genetic algorithm in continuous manufacturing process. The guide genetic algorithm(GGA) is an extended genetic algorithm(GA) using penalty function and population diversity index to increase forecasting accuracy. GGA adds to the canonical GA the concept of a penalty function to avoid selecting the unproductive chromosomes and to make a proper searching direction. Also, GGA modifies the current population using the similarity of chromosomes to avoid falling into the trap of local optimal solution. For investigation GGA performance, we used a set of real data that was collected in local glass melting processes, and experimental results show the proposed model results in the better forecasting accuracy than linear regression model and canonical GA.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.665-670
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• 2002

Pleasantness or quietness becomes one of the most important factors for residential designs recently. Especially for apartments, the noise generated by falling objects becomes a sensitive issue these days. To overcome the problem of the impact noise in apartments, the floor design has been changed. To reduce the transmissibility of the noise, composite floor structures are devised and implemented for the construction of apartments. In this paper, the noise reduction performance of a composite floor plate with holes is analyzed. Computational modelings for the structures are developed and its performance is evaluated by using the finite element method. The results show that the noise can be well reduced with the multi-layer composite floor plates with holes.

• The Korean Journal of Rheology
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• v.4 no.1
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• pp.25-34
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• 1992

저속으로 낙하하는 원통형 미소체의 유체역학적 거동에 대하여 점탄성 유체의 비 뉴우튼 성질의 영향에 관해서 연구가 수행되었다. 원통형 미소체의 직경 및 직경에 대한 길 이의 비 (Aspect Ratio)의 영향에 관해서도 또한 고찰하였으며 본 실험에서는 뉴우튼 유체 로서 99.5%의 글리세린용액과 점탄성 유체로서 1,000 wppm 의 polyacyla-mide(Separan AP-273) 수용액이 각각 사용되었다. 낙하하는 미소체의 Aspect Ratio가 증가할수록 무차원 최종속도는 뉴우튼 유체내에서 보다 점탄성 유체내에서 그증가속도가 더욱 커짐을 보였다. 뉴우튼 유체 내에서 낙하하는 원통형 미소체의 마찰저항 계수는 실험데이타로부터 계산된 값과 이론치가 비교적 잘일치하나 점탄성 유체에 관한 마찰저항 계수는 본 실험의 결과치와 무한히 긴 원통형 미소체에 대한 기존연구의 이론값과는 상당한 차이가 있음을 알수 있었 다, 이는 점탄성 유체내에서 수직으로 낙하하는 원통형 미소체의 저항계수가 k(즉 용기의 직경에 대한 미소체 직경의 비), power-law index 레이놀즈수 뿐아니라 aspect ratio를 포함 하는 새로운 관계식이 도출되어야 함을 분명히 보여주고 있다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.2
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• pp.144-150
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• 2003

Pleasantness or quietness becomes one of the most important factors for residential and office building designs recently. Especially for apartments, the noise generated by falling objects becomes a sensitive issue these days. To overcome the problem of the impact noise in apartments, the floor design has been changed. To reduce the transmissibility of the noise. composite floor structures ate devised and implemented for the construction of apartments. In this paper. the noise reduction) performance of a composite floor plate with holes is analyzed. Computational models for the structures are developed and its Performance is evaluated by using the finite element method. The results show that the noise can be significantly reduced with the multi-layer composite floor plates with holes.

• International Journal of Highway Engineering
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• v.19 no.5
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• pp.59-68
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• 2017

PURPOSES : The objective of this study is to evaluate the potential risk level of road cave-ins due to subsurface cavities based on the deflection basin measured with falling weight deflectometer (FWD) tests. METHODS: Ground penetrating radar (GPR) tests were conducted to detect road cavities. Then FWD tests were conducted on 13 pavement test sections with and without a cavity. FWD deflections and a deflection ratio was used to evaluate the effect of geometry of the cavity and pavement for road cave-in potentials. RESULTS : FWD deflection of cavity sections measured at 60 cm or a closer offset distance to a loading center were 50% greater than more robust sections. The average deflection ratio of the cavity sections to robust sections were 1.78 for high risk level cavities, 1.51 for medium risk level cavities, and 1.16 for low risk level cavities. The relative remaining service life of pavement with a cavity evaluated with an surface curvature index (SCI) was 8.1% for the high level, 21.8% for the medium level, and 89.8% compared to pavement without a cavity. CONCLUSIONS : FWD tests can be applied to detect a subsurface cavity by comparing FWD deflections with and without a cavity measured at 60 cm or a closer offset distance to loading center. In addition, the relative remaining service life of cavity sections based on the SCI can used to evaluate road cave-in potentials.

• Journal of the Korean Geosynthetics Society
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• v.10 no.3
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• pp.1-8
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• 2011

This paper presents the performance evaluation of asphalt pavement reinforced with fiber sheet type of geosynthetics and observations conducted to evaluate the practical efficiencies and performance of overlay asphalt pavement reinforced with geosynthetics. In this study, performance evaluation were performed for the six section of construction site. The performance indcators of asphalt pavement reinforced with geosynthetics has been collected Automatic Road Analyzer (ARAN), Falling Weight Deflectometer (FWD) and have been analyzed for rutting, cracking ratio, falling weight and international roughness index. As a result of performance evaluations, geosynthetics reinforced asphalt pavement is sigficant effect on increasing a cracking resistance than the non-reinfroced asphalt pavement, also rutting and crak is slowly increase as incerasingly performance period.

• Clean Technology
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• v.10 no.2
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• pp.111-120
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• 2004

Manufacturing with a chemical for eco-friendly leather for nitrogen decrease of leather falling hair process waste water and the falling hair process that a number to decrease with sulfuration water decrease, a pollution load of COD, BOD. In this study manufactured lining agent and the unhairing assist product which did urea, mercaptan by basic matter. As a result of having dealt in hair saving process, compared, and was recalled by the existing hair burning process recovered hair, increased approximately 2times. Grain state to influence the yield that was quality of leather and an index of productivity evaluation, an improvement of contraction phenomenon (drawing) were possible. Is increased going seal, tear strength property of matter and softness and touch leather native nature in wet blue. Also, it is possible confirmation with decrease being more possible than about 50% COD, T-N density in a hair saving waste water.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.113-119
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• 2019

Objective: The purpose of this study was to investigate the effect of the falls on the center of pressure (CoP) complexity during gait using non-linear approximate entropy (ApEn). Method: 20 elderly women with experience of falling ($age=72.55{\pm}5.42yrs$; $height=154.40{\pm}4.26cm$; $body\;weight=57.40{\pm}6.21kg$; $preferred\;gait\;speed=0.52{\pm}0.17m/s$) and 20 elderly women with no experience of falling ($age=71.90{\pm}2.90yrs$; $height=155.28{\pm}4.73cm$; $body\;weight=56.70{\pm}5.241kg$; $preferred\;gait\;speed=0.56{\pm}0.13m/s$) were recruited for the study. While they were walking at their preferred gait speed on a treadmill (instrumented dual belt treadmills, Bertec, USA) with a force plate CoP data were collected for the 20 strides. The complexity of the CoP was analyzed using the ApEn technique. Results: The ApEn of the medial-lateral CoP in the fallers showed smaller about 16% compared to the non-fallers (p<.05). The ApEn of the antero-posterior CoP of the fallers showed smaller about 12% compared to the non-fallers, but the difference was not statistically significant. Conclusion: Based on the results of this study, the reduction of the medio-lateral CoP complexity in the elderly gait would be an index to determine the potential fall.

• The Journal of Korean Physical Therapy
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• v.29 no.1
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• pp.33-38
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• 2017

Purpose: This study was conducted to investigate the effects of variations in arm swing during gait on movement of the trunk and pelvis. During the gait task, the angle of the trunk and pelvic rotation were analyzed according to arm swing conditions. Methods: Seventeen healthy males participated in this study. All subjects were analyzed for gait on a treadmill three times each under three different types of arm swing conditions - natural arm swing, restricted arm swing using a phone, restricted swing in both arms. 3-D motion analysis systems were used to collect and analyze the kinematic data of trunk and pelvic movements, and repeated one-way ANOVA was used to compare the trunk and pelvic kinematic data and symmetry index. The level of significance was ${\alpha}=0.05$. Results: The results showed kinematic differences in trunk and pelvic during gait based on the arm swing conditions. Specifically, there were significant differences in trunk rotation, left and right trunk rotation and symmetry index of trunk rotation during gait among the three arm swing conditions. ROM was used to calculate a symmetry index (SI) based on the average left and right trunk rotation in which a value closer to zero indicated better balance. The SI obtained for arm swing restricted with the phone was closer to -1 than the other conditions. Conclusion: Restricted arm swing due to use of a phone had the possibility to induce instability of postural control while walking, which could be seen to suggest a risk of falling during gait.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.54-61
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• 2017

Strengthening the protection and management of very old trees is an important aspect of urban site preservation, urban design and construction. Rating various danger factors to evaluate the degree of danger posed can help to create the correct protective countermeasures. In order to develop the danger evaluation index, this study performed four round surveys by using the Delphi method and collected opinions from experts in related fields. Necessary indexes were fully added in the first and second round while the indexes falling beyond the guidelines were deleted. From the final analysis results, five areas derived a total of forty-one indicators to create a degree of danger index from vigour status, growth and development status, diseases and insect pests, soil status, and management status. The degree of danger evaluation index can provide basic data for the protection of very old trees.