• Journal of the Ergonomics Society of Korea
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• v.18 no.1
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• pp.133-147
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• 1999

Traffic signs without a cognitive consideration in their design may cause information-processing problem that could result in a mental confusion among drivers often lead to a serious traffic accident. Therefore, in this study, several traffic signs currently used in Seoul Metropolitan area have been sampled and analyzed to identify design problems that usually caused by neglecting drivers cognitive ability. To classify the practical design problems, five major information-processing problems have been suggested: indistinguishable information, information conflict, missing information, sign-load mismatch, and information overload. In order to solve these cognitive problems, new traffic signs have been suggested in this study. An experiment was also performed to validate the new traffic sign. Twenty-four healthy subjects participated in the experiment. They were asked to answer the Question after observing the traffic signs continuously displayed on computer screen. The result indicated that subjects improved the accuracy in understanding the signs by 1.4 times when they used the suggested traffic sign compared to the old one. Based upon the results, a cognitive guideline was suggested for correct and speedy reading of traffic signs by improving information processing and reducing of human error. In conclusion, the traffic sign may well be applied to design an intelligent traffic sign system to increase the safety and comfort of drivers, especially in complex load condition.

• Fashion & Textile Research Journal
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• v.20 no.6
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• pp.704-712
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• 2018

This study analyzed working postures using the Ovako Working Posture Analysis System (OWAS) to improve work clothes for construction workers. A video taken at a construction work site was stopped at regular intervals and the postures of relevant body parts proposed by OWAS was recorded. Additionally, based on analysis of the working postures code, the level of work action for each postures was classified from stage I to IV. General workers frequently straightened or bent forward at the waist, and used their legs to stand, bend, or walk. Wood workers moved extensively from the waist, keeping their legs relatively straight and their arms held below their shoulders, repeatedly tapping with a hammer weighing less than 10.0kg. Rebar bending workers mainly bent forward at the waist, with both legs bent or standing with one leg bent. Rebar transport and fixing workers walked with the waist straight, and occasionally one or both hands held above the shoulders. Their work also involved holding a hook, which weigh less than 10.0kg, in their hands, and the difficult task of lifting and placing long rebars, which weigh from 10.0 to 20.0kg or more. Concrete pouring workers bent or twisted their back to the side. Therefore, this study suggests that design goals should be different when developing workwear for each type of worker.

• Journal of agricultural medicine and community health
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• v.44 no.3
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• pp.138-143
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• 2019

Objectives: The purpose of this study was to assess the ergonomic risk factors in beekeeping, and to evaluate the effectiveness of assistive device hive lift. Methods: This study included 30 subjects of beekeeper in Pocheon, Korea. We assessed the ergonomic risk of main task in beekeeping with NLE, OWAS and evaluate the effectiveness of hive lift. We also surveyed prevalence of musculoskeletal symptoms among the subjects based on the Korea Working Condition Survey. Results: Moving to different floral origin, internal inspection of beehives, feeding syrup is the most burdensome to musculoskeletal system (NLE LI value=2~3. OWAS action category=4). The prevalence of musculoskeletal symptoms (lower and upper extremities) among the subjects was over 80 %. The introduction of assistive devices in the three hazardous tasks has dramatically reduced the risk by removing manual lifting hives (OWAS action category<1). Conclusions: Beekeeping is a heavy workload on the musculoskeletal system because it has a lot of manual lifting task. As a result of applying the hive lift, the burden could be reduced.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.203-210
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• 2010

For the development of a better product which fits to the target user population, physical workloads such as reach and visibility are evaluated using digital human simulation in the early stage of product development; however, ergonomic workload assessment mainly relies on visual observation of reach envelopes and view cones generated in a 3D graphic environment. The present study developed a quantitative assessment method of physical workload in a digital environment and applied to the evaluation of a Korean utility helicopter (KUH) cockpit design. The proposed assessment method quantified physical workloads for the target user population by applying a 3-step process and identified design features requiring improvement based on the quantified workload evaluation. The scores of physical workloads were quantified in terms of posture, reach, visibility, and clearance, and 5-point scales were defined for the evaluation measures by referring to existing studies. The postures of digital humanoids for a given task were estimated to have the minimal score of postural workload by finding all feasible postures that satisfy task constraints such as a contact between the tip of the index finger and a target point. The proposed assessment method was applied to evaluate the KUH cockpit design in the preliminary design stage and identified design features requiring improvement. The proposed assessment method can be utilized to ergonomic evaluation of product designs using digital human simulation.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.147-152
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• 2007

The aim of this study was to evaluate the musculo-skeletal symptomatic features of municipal sanitation workers and to compare differences of the musculo-skeletal symptoms by work types. We conducted descriptive cross-sectional survey concerning the musculo-skeletal symptomatic features of 315 street cleaners in Seoul and GyeongGi Province, Korea, during 2 weeks of September 2006. Questionnaires were consisted of general characteristics, occupational characteristics and musculo-skeletal symptoms. And we observed their works and evaluated their movement and posture by REBA. For work types, tools and subjective physical work loading, there were statistical difference whether or not NIOSH symptom positive on upper limb. Musculo-skeletal symptoms on upper limb were claimed from 43.2% of street cleaners, more than in 32.4% of cleaners. Musculo-skeletal symptoms on upper limb were reported higher in the group who felt their subjective physical work loading severe than in the otherwise group. The REBA results were over 'high risk stage' in street cleaners. Street cleaners had more repetitive motions than solid waste collectors on upper limbs. Works according to the criteria of musculoskeletal burdened work by the Ministry of Labor results were over 'high risk stage' of No. 2 and No. 4 in street cleaners. We found that street cleaners complained musculo-skeletal symptoms on upper limb more than solid waste collectors. This study suggests that it is necessary for street cleaners to carry out the prevention program of musculo-skeletal diseases. For street cleaner, the measure plans such as job rotation, automatic street sweepers, reducing work hours are helpful in preventing musculoskeletal symptoms on the upper limb.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.45-58
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• 2008

Ergonomic techniques have been required to analyze the effectiveness of functional clothing design improvement in a systematic and analytic manner. The goals of the present study are to: (1) comprehensively and analytically examine the effectiveness of clothing improvement by using the relationship analysis between clothing design components (D) and ergonomic evaluation measures (E) and (2) prove the usefulness of cost-effectiveness analysis for clothing design optimization. The cost effectiveness analysis is comprised of the preliminary evaluation based on expertise and the in-depth evaluation where the D-E relationship analysis is applied. As a result of the cost effectiveness analysis applied to flame-proof clothing, an optimal design was identified by analyzing costs and qualitative/quantitative effects. In the preliminary evaluation, the expected effectiveness of each design alternative on wear efficiency and wear comfort was estimated. In the in-depth evaluation, however, the effectiveness of each design alternative was analyzed by quantitative evaluation in a wearing test using a questionnaire prepared based on the D-E relationship analysis. It was concluded that the D-E relationship analysis and the cost-effectiveness analysis are useful for comprehensive evaluation and optimization of functional clothing design.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.440-444
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• 2011

집중호우로 인한 자연재해는 대부분 하천을 중심으로 발생하며, 설계빈도를 초과한 홍수량을 인해 제방을 월류하거나 제방의 붕괴로 인해 피해가 발생하게 된다. 일반적으로 제방 붕괴와 같은 홍수의 위험으로부터의 취약성을 감소시키는 동시에, 홍수에 의한 피해에 대해 빠른 복구가 이루어질 수 있도록 하는 정책을 홍수 경감 대책이라고 하며, 홍수에 대비하는 정책은 홍수의 주기 및 재해특성과 관련이 있고, 인간과 사회에 대한 잠재적인 피해를 줄이기 위해 필요하다. 본 연구에서는 여러 가지 이유에 의해 발생하는 제방의 붕괴 현상이 복잡한 수리학적 또는 토질 기초 공학적 현상 등에 의하여 일어나기 때문에 이에 대한 발생 원인을 규명하는 것이 쉬운 일은 아니나, 일반적 월류, 세굴, 침하 및 지진 등으로 꼽히는 제방 붕괴 위험 원인들을 검토하여 제방 붕괴를 유발할 수 있는 하천의 위험 인자들을 제시하고자 하였다. 이를 토대로 하천 내 주요지점에 대한 위험도를 산정할 수 있는 기법을 개발하고 시험유역을 대상으로 하천에서 발생 가능한 위험 지구를 선정하여 그 타당성을 검토하고자 하였다.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.3
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• pp.27-43
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• 1991

연소 가공은 고품질 고정도를 필요로 하는 경우 매우 유효한 가공방법이지만 그 공정이 많은 Parameter에 의해 구성되기 때문에 동일한 조건에서도 정량적인 평가가 어려우므로 작업현장 에서는 과학적 원리와 공학적 지식 보다는 숙련자의 경험과 기능에 의존하고 있는 실정이다. 본 연구에서는 이와 같은 국면에 대처한 문제 해결을 위해 Computer가 인간사고에 근접 할 수 있도록 Fuzzy 이론과 Default 이론을 도입하고 전문가의 이론적 지식과 숙련자의 감각적 지식을 적극 수용 하여 연소용 Expert system (최적 가공 조건의 설정 System과 Trouble shooting system)을 개발하였다. 또한 연소 가공 Data의 불확실한 애매성을 효과적으로 이용 할 수 있도록 Fuzzy 가능성이론에 의해 가공 Datad을 회귀 분석하여 실가공 Data base에 축적시켜 재활용토록 설계하었으며 개발된 본 System 의 실행 결과 그 활용성이 높음을 입증하였다.

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.27-34
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• 2016

For the prevention of marine casualties, international bodies have mainly focused on strengthening ship's stability and design, maritime education and training, and improving maritime traffic environment. Statistics analysis on marine casualties showed that most of casualties occurred in coastal waters, especially by human elements. In order to review the conformity of existing prevention measures with the result of the statistics analysis, the IMO's SHELL model was applied to the established measures. As a result, ergonomic approaches were needed for the prevention of human errors in coastal waters, so that the priority should be given to the interface between ship's operator and navigational environment. For this study, Rasmussen's SRK pyramid, which showed decision making mechanism of human, and the US Coast Guard's investigation manual on marine casualties concerning the collapse of safe maritime transportation system were reviewed, and the merits and demerits within the risk assessment tools such as IWRAP, PAWSA, ES model, PARK model, and NURI model were also studied. Although the effectiveness of the existing risk assessment models was proved in ports and approaching channels, it is concluded that the need of new models for converting Korean seafarers' qualitative risk to quantitative risk was proposed so as to print hazard maps which make seafarers instinctively recognize comparative hazard levels of coastal waters.

• Journal of Navigation and Port Research
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• v.37 no.4
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• pp.401-407
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• 2013

In parallel with the development of ship equipment, bridge systems have been improved, but marine accidents due to human error have not been reduced. Recently, research in nautical bridge equipment has focused on suitable ergonomic designs in order to reduce these errors due to human factors. In a bridge of a ship, there are numerous auditory signals that deliver important information clearly to the sailors. However, only a few studies have been conducted related to the human recognition of these auditory signals. There are three types of auditory signals: voice alarms, abstract sounds, and auditory icons. This study was conducted in order to design more appropriate auditory icons using a sensibility evaluation method. The auditory icons were rated to have five warning situations (engine failure, fire, steering failure, low power, and collision) using the Semantic Differential Method. It is expected that the results of this study will be used as basic data for auditory displays inside bridges and for integrated bridge alarm systems.