• 한국산업정보학회논문지
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• 제17권4호
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• pp.9-15
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• 2012

This paper presents application of a new tactile slippage sensation algorithm in robot hand control system. The optical three-axis tactile sensor is a type of tactile sensor capable of defining normal and shear forces simultaneously. The tactile sensor is mounted on fingertip of robotic hand. Shear force distribution is used to define slippage sensation in the robot hand system. Based on tactile slippage analysis, a new control algorithm was proposed. To improve performance during object handling motions, analysis of slippage direction is conducted. The control algorithm is classified into two phases: grasp-move-release and grasp-twist motions. Detailed explanations of the control algorithm based on the existing robot arm control system are presented. The experiment is conducted using a bottle cap, and the results reveal good performance of the proposed control algorithm to accomplish the proposed object handling motions.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.121-127
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• 2013

In this study, suspension geometry is controlled to improve vehicle handling performance. The toe and camber of the rear suspension is controlled independently by using a double knuckle structure designed to enhance the vehicle cornering stability. Camber and toe changes in the rear wheel during high speed turning maneuver are important factors that influence the vehicle stability. Toe in the rear outer wheel plays a dominant role in cornering. A control algorithm for the camber and the toe angle input is developed to carry out the control simulation of the vehicle such as single lane change, the steady state cornering, the double lane change and the step steering simulation. Effects of the camber and toe angle control are analyzed from the computer simulations. A double lane change simulation revealed that the suspension mechanism with variable camber angle and variable toe angle decreases the peak body slip angle and peak yaw rate, 50% and 10%, respectively.

• 산업경영시스템학회지
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• 제45권3호
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• pp.40-48
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• 2022

An automated material handling system (AMHS) has been emerging as an important factor in the semiconductor wafer manufacturing industry. In general, an automated guided vehicle (AGV) in the Fab's AMHS travels hundreds of miles on guided paths to transport a lot through hundreds of operations. The AMHS aims to transfer wafers while ensuring a short delivery time and high operational reliability. Many linear and analytic approaches have evaluated and improved the performance of the AMHS under a deterministic environment. However, the analytic approaches cannot consider a non-linear, non-convex, and black-box performance measurement of the AMHS owing to the AMHS's complexity and uncertainty. Unexpected vehicle congestion increases the delivery time and deteriorates the Fab's production efficiency. In this study, we propose a Q-Learning based dynamic routing algorithm considering vehicle congestion to reduce the delivery time. The proposed algorithm captures time-variant vehicle traffic and decreases vehicle congestion. Through simulation experiments, we confirm that the proposed algorithm finds an efficient path for the vehicles compared to benchmark algorithms with a reduced mean and decreased standard deviation of the delivery time in the Fab's AMHS.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.904-911
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• 2022

Occlusion is one of the most challenging problems for computer vision-based construction monitoring. Due to the intrinsic dynamics of construction scenes, vision-based technologies inevitably suffer from occlusions. Previous researchers have proposed the occlusion handling methods by leveraging the prior information from the sequential images. However, these methods cannot be employed for construction object detection in non-sequential images. As an alternative occlusion handling method, this study proposes a data augmentation-based framework that can enhance the detection performance under occlusions. The proposed approach is specially designed for rebar occlusions, the distinctive type of occlusions frequently happen during construction worker detection. In the proposed method, the artificial rebars are synthetically generated to emulate possible rebar occlusions in construction sites. In this regard, the proposed method enables the model to train a variety of occluded images, thereby improving the detection performance without requiring sequential information. The effectiveness of the proposed method is validated by showing that the proposed method outperforms the baseline model without augmentation. The outcomes demonstrate the great potential of the data augmentation techniques for occlusion handling that can be readily applied to typical object detectors without changing their model architecture.

• 한국환경보건학회지
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• 제46권2호
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• pp.232-244
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• 2020

Objectives: The purpose of this study is to develop a management system for the safe handling of chemicals and related health management based on reporting under the Chemical Control Act (CCA). It is used to search handling information by constructing data linked to the name of companies, chemicals, products, etc. Methods: Due to the differences in submission periods for each reporting regulation of the Chemical Control Act, the data used is as follows: A statistical survey collected 26,222 companies in 2014 and 2016, Pollutant Release Transfer Registers (PRTR) collected 4,234 companies in 2015-2017, performance reports by handlers of hazardous chemical substances collected 14,658 companies in 2016-2018, and declarations for import of toxic chemicals collected 892 companies in 2016-2017. The total information on 36,080 companies is standardized based on company ID, name, business registration number, address, and more. The data were classified into information such as company, chemical, and product name and amounts handled and released, and then extracted according to criteria to establish relationships among classified information. Results: A search service was developed for handling information on chemical substances for reporting data by linking four reporting data: statistical survey, PRTR, performance report by handler of hazardous chemical substances, and declaration for import of toxic chemicals under the CCA. It was composed of five menus to search by regulation type, reporting regulation, companies and chemicals, and system management. Conclusion: It is necessary to use data linked by company, region, and chemical to respond and to prevent chemical accidents. In addition, these items can be utilized to perform handling and safety management of chemicals according to whether regulations under the CCA may be implemented.

• 한국산학기술학회논문지
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• 제22권6호
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• pp.215-225
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• 2021

본 연구는 국내 중견기업의 재난 및 안전관리 실무자를 대상으로 재난 및 안전관리체계에 대한 안전관리자의 특징과 재난 및 안전관리 능력 및 역량, 재난 및 안전관리 활동성과 간의 영향 관계를 실증적으로 검증하는 것을 목적으로 하였다. 본 연구는 기업에 재직 중인 재난 및 안전관리체계 실무자 509명을 대상으로 설문조사를 실시한 후, 자료를 분석하였다. 분석결과, 첫째, 실무자의 기업 재난 및 안전관리체계에 대한 특징은 활동성과에 정적으로 유의한 영향을 미치는 것으로 나타났다. 둘째, 실무자의 기업 재난 및 안전관리체계에 대한 특징은 능력 및 역량에 정적으로 유의한 영향을 미치는 것으로 나타났다. 셋째, 실무자의 재난 및 안전관리 능력 및 역량은 활동성과에 정적으로 유의한 영향을 미치는 것으로 나타났다. 넷째, 실무자의 기업 재난 및 안전관리체계에 대한 특징과 활동성과의 관계에서 실무자의 재난 및 안전관리 능력 및 역량은 매개역할을 하는 것으로 나타났다. 본 연구를 통해 기업체의 재난 및 안전관리 실무자의 재난 및 안전관리 실태와 의식을 분석, 평가하고, 이를 바탕으로 합리적이고 효율적인 재난 및 안전관리 업무를 위한 방향성을 제안하였다.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.287-295
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• 2020

Group method of data handling (GMDH) is considered one of the earliest deep learning methods. Deep learning gained additional interest in today's applications due to its capability to handle complex and high dimensional problems. In this study, multi-layer GMDH networks are used to perform uncertainty quantification (UQ) and sensitivity analysis (SA) of nuclear reactor simulations. GMDH is utilized as a surrogate/metamodel to replace high fidelity computer models with cheap-to-evaluate surrogate models, which facilitate UQ and SA tasks (e.g. variance decomposition, uncertainty propagation, etc.). GMDH performance is validated through two UQ applications in reactor simulations: (1) low dimensional input space (two-phase flow in a reactor channel), and (2) high dimensional space (8-group homogenized cross-sections). In both applications, GMDH networks show very good performance with small mean absolute and squared errors as well as high accuracy in capturing the target variance. GMDH is utilized afterward to perform UQ tasks such as variance decomposition through Sobol indices, and GMDH-based uncertainty propagation with large number of samples. GMDH performance is also compared to other surrogates including Gaussian processes and polynomial chaos expansions. The comparison shows that GMDH has competitive performance with the other methods for the low dimensional problem, and reliable performance for the high dimensional problem.

• 대한영양사협회학술지
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• 제22권4호
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• pp.320-339
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• 2016

This study was conducted to identify risk factors to ensure food safety by evaluating cook supervisors' perceived performance of vegetable safety management at Korean food restaurants in Daegu. Recognition of the potential foodborne illness caused by vegetables was 2.60/5 on average. Inspection items with low scores by respondents during food safety inspection by government agencies were "Wash and sanitize vegetables" and "Keep washed and cut vegetables in the refrigerator". As for storage, perceived performance of "Store vegetable in the refrigerator less than 70% of the refrigerator capacity" scored less than 4 out of 5. About 86% of respondents answered "Water-only washing" for vegetable washing. For perceived performance of vegetable cooking, service, and leftover handling, 11 and three items out of 13 were significantly different depending on the size of restaurants and possession of culinary arts certificates, respectively. Based on results, it is necessary to provide food safety training programs for handling vegetables in order to increase knowledge of cook supervisors. In addition, intensive on-site guidance for safety management of vegetables is needed.

• 산업경영시스템학회지
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• 제38권4호
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• pp.202-211
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• 2015

Companies build the factory automation system to improve management effectiveness and productivity as prime strategies for sustainable growth. But most companies undergo various trials and errors while carrying out the project without elaborate preparation stage for factory automation. In this study, we tried to verify what factors are critical to effectively building distribution automation system, which is a branch of factory automation system. A consulting model for setting up a Material Handling Automation System by utilizing the Stage-Gate Process, which is product development process was studied. 29 material handling automation projects carried out between the year 1990 to 2013 at K-Company were selected. Interviews with the project managers, operators and maintenance personnels, various records and current status of the projects were used as data for structural equations based on the Milan consulting model and existing researches of factory automation, CIM for material handling automation. Creating effective basis of production, material handling system and energy saving system with expert review, when preparing a material handling automation project, help promote the project planning thus contributing to the performance of the resulting system, which appears though rather weakly in our data. Also the effect of material handling automation can be enhanced through sufficient and effective links to the relevant environments such as production logistics management and automated warehouses. More detailed planning characteristics of project promotion or some time-series data of effective Material Handling Automation System could enhace furthur studies. We propose a consulting model for setting up an efficient material handling automation system.

• 해양환경안전학회지
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• 제12권1호
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• pp.39-45
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• 2006

항공기와 자동차의 운전을 중심으로 알코올이 인간의 행동과 수행도에 미치는 연구가 많이 이루어져 왔으며 이를 통해 선박의 당직 전 및 당직 중의 음주는 이어지는 행동에 큰 영향을 미친다고 할 수 있다. 본 연구에서는 승선 중 음주 실태를 파악하기 위하여, 선택형 앙케트를 교육중인 사관들에게 배포하여 118명으로부터 얻어진 결과를 조사하였다. 알코올 의존도에 관한 자가진단결과에 따르면, 조사대상자의 27% 이상이 알코올 남용 증세를 나타내었다. 또한, 승선 중 음주 현황 및 인식에 관한 사항을 정리하여, 선박운항 시뮬레이터를 이용한 음주 운항 시나리오를 마련하였으며, 알코올이 선박운항능력에 미치는 영향을 알아보았다. 실험결과를 분석한 결과, 알코올의 섭취가 선박운항능력을 다소 저하시키는 것으로 나타났다. 이러한 분석결과는 앞으로 선박운항자의 피로에 의한 해양사고 발생을 근본적으로 줄이기 위한 기초자료로 활용할 수 있을 것이다.