• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.130-134
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• 1992

The ability of a robot system to comply to an environment via the control of tool-environment interaction force is of vital for the successful task accomplishment in many robot application. This paper presents the implementation of external force control for two dimensional contour following task using a commercial robot system. Force accommodation is used since a constraint imposed in our work is not to modify the commercial robot system. A linear, decoupled model of two dimensional contour following system in the discrete time domain is derived first. Then the experimental verification of linear control is obtained using a PUMA 560 manipulator with standard Unimation controller, Astek FS6-120A six axis wrist force sensor attached externally to the arm and LSI-11173 microcomputer. Experimentally obtained data shows that the RMS contact force error is 0.8246 N when following the straight edge and 2.3768 N when following 40 mm radius curved contour.

• 대한가정학회지
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• 제33권3호
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• pp.71-84
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• 1995

The purpose of this study is to investigate the effect of wives' demographic variables, the family cohesion and adaptability perceived by dual-career wives on household task performance. The subject of this study were 391 employed professional wives working in seoul. Using the questionnary, the data was obtained and the data was analysed by percentile, frequency, ANOVA, multiple regression. The results were as follows. 1) the family cohesion and adaptability scores showed a little higher than those of previous research. Number of children, age of the youngest child and family pattern were statistically significant in the family cohesion, number of children and family pattern were statistically significantly in the family adaptability. 2) The division of housework by family members was influenced by the family adaptability and family pattern. The family cohesion was a significant determinant of the division of housework by husband. The standard of housework was influenced by wives' age, the family cohesion and a housework time.

• Journal of Dairy Science and Biotechnology
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• 제27권2호
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• pp.49-53
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• 2009

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.615-624
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• 2008

In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1 %), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.2758-2768
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• 2014

과업 및 관계갈등의 차별적 효과에 대한 연구에 따르면, 과업갈등이 혁신적 성과에 긍정적 영향을 주는 반면, 관계갈등이 혁신적 성과에 부정적 영향을 준다고 주장하고 있다. 하지만, 과업갈등과 관계갈등 간의 밀접한 상호관련성을 고려해 본다면, 혁신적 성과에 긍정적 영향을 주는 과업갈등은 관계갈등으로 전이되면서, 혁신적 성과에 부정적 영향을 줄 수 있다. 따라서 과업갈등이 관계갈등으로 전이되는 것을 약화시키는 경영관리 방식이 필요하며, 개인이 보유한 사회 정체성이고, 팀에 대한 감정적 인지적 유대인 팀 정체화는 효과적인 갈등관리 방안일 수 있다. 본 연구는 213명의 종업원들을 통해 수집한 자료를 토대로, 이러한 논리가 기업현장에서 실제로 성립되고 있음을 확인할 수 있었다. 연구결과를 토대로 연구의 시사점과 향후 연구방향을 제시하였다.

• Communications for Statistical Applications and Methods
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• 제8권1호
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• pp.193-207
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• 2001

When designing a test set, we need to consider constraints on items that are deemed important by item developers or test specialists. The constraints are essentially on the components of the test domain or abilities relevant to a given test set. And so if the test domain could be represented in a more refined form, test construction would be made in a more efficient way. We assume that relationships among task abilities are representable by a causal model and that the item response theory (IRT) is not fully available for them. In such a case we can not apply traditional item selection methods that are based on the IRT. In this paper, we use entropy as an uncertainty measure for making inferences on task abilities and developed an optimal item selection algorithm which reduces most the entropy of task abilities when items are selected from an item pool.

• 대한의용생체공학회:의공학회지
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• 제28권3호
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• pp.417-422
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• 2007

In this study, we investigated spatio-temporal eye-hand coordination by the "Global effect paradigm", a target-distracter configuration Global effect is observed a variety of visual tasks, for example, during rapid automatic tracking, scanning for target detail, and the comparison of target configurations. Global effect used to investigate eye-hand coordination with a task that presents a target close to a distracter. Eight young subjects participated in the experiments. The experiments consist of using a distracter less eccentric than the targe1 and using a distracter more eccentric than target. Each experiment consist of tasks which are making reference, pointing the target with watching visual stimulation(saccade) and pointing the target. The subject's task was to move towards the target as quickly as possible. We measured the eye movement by using EOG and the hand movement by using NDI Optotrak system. This study shows that eye and hand movement exists for global effect paradigm in spatio-temporal coordination.

• 한국환경농학회지
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• 제33권4호
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• pp.254-261
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• 2014

홍고추 생산을 위해 논 시설재배지의 토양화학성을 개선하고 생산성에 미치는 영향을 조사하기 위해 고추 정식 전에 규산질비료를 0, 100, 200, 300 kg/10a를 처리하였다. $N-P_2O_5-K_2O$는 토양검정에 의해 밑거름으로 질소 50%, 인산 100%, 칼리 60%을 시비한 후, 천하대세 품종을 $120{\times}45cm$ 간격으로 정식하고, 웃거름은 1, 2, 4차 수확 후 3회에 나누어 질소와 칼리를 시비하였다. 최종 5차 수확기에 조사한 토양 pH, 유효인산, 치환성 $Ca^{2+}$은 규산질비료 처리량에 따라 증가하였고, EC는 감소하였다. 유기물함량은 대조구보다 높았고, 치환성 $K^+$은 100과 200 kg/10a, $Mg^{2+}$는 300 kg/10a 처리구에서 높았다. 규산질비료가 정식 60일까지 지상부 생육에 미치는 영향은 적었다. 고추 1차 수확기 잎에 함유되어 있는 N과 P는 규산질비료 처리량과 반비례 관계였고, K. Ca, Mg은 300 kg/10a 처리구에서 가장 많았다. 홍고추 수량은 대조구에 비해 규산질비료 처리구에서 9.0~11.8% 증가하였고, 200 kg/10a 처리구에서 상품과율이 97.3%로 가장 높았고, 비상품과는 105 kg, FW/10a 수준으로 가장 낮았다. 규산질비료 시비량과 건고추수량의 관계식($Y=-0.0022X^2+0.827X+645.7$, $R^2=0.9838$)에 따른 최고수량은 723.4 kg/10a, 이때 규산질비료 시비량은 187.9 kg/10a 이었다. 이상의 결과에서 보는 바와 같이 답전윤환 시설재배지에 규산질비료를 밑거름으로 사용하면 토양화학성이 개선되고, 비상품과 수량이 감소하고 생산량이 증가하였다.

• 대한인간공학회지
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• 제30권1호
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• pp.75-86
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• 2011

This paper describes several current research activities and the field techniques for the prevention of human errors during the operation of nuclear power plants(NPPs). The human aspects such as 'fitness for the duties', 'job competence and suitability', 'types of communication', 'behaviors of field workers', 'teamwork of main control room crews', 'task procedures', etc. have been investigated for improving the performance of operating personnel in NPPs. We decide to develop a set of the complementary techniques for the reduction of human errors. The set of techniques developed includes teamwork criteria, jobs fitness analysis, procedure enhancement guide, 3-way communication, campaign posters, a behavior based safety program, a procedure guideline, and a task hazard identification method for the field practitioners in NPPs. These can offer a set of significant human error countermeasures to be considered for analyzing and reducing human error in NPPs as well as other fields of industry.

• ETRI Journal
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• 제29권3호
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• pp.259-269
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• 2007

The ubiquitous flexible operating system (UbiFOS) is a real-time operating system designed for cost-conscious, low-power, small to medium-sized embedded systems such as cellular phones, MP3 players, and wearable computers. It offers efficient real-time operating system services like multi-task scheduling, memory management, inter-task communication and synchronization, and timers while keeping the kernel size to just a few to tens of kilobytes. For flexibility, UbiFOS uses various task scheduling policies such as cyclic time-slice (round-robin), priority-based preemption with round-robin, priority-based preemptive, and bitmap. When there are less than 64 tasks, bitmap scheduling is the best policy. The scheduling overhead is under 9 ${\mu}s$ on the ARM926EJ processor. UbiFOS also provides the flexibility for user to select from several inter-task communication techniques according to their applications. We ported UbiFOS on the ARM9-based DVD player (20 kB), the Calm16-based MP3 player (under 7 kB), and the ATmega128-based ubiquitous sensor node (under 6 kB). Also, we adopted the dynamic power management (DPM) scheme. Comparative experimental results show that UbiFOS could save energy up to 30% using DPM.