• Korean Management Science Review
• /
• v.11 no.1
• /
• pp.91-106
• /
• 1994

In mixed model assembly lines, products are assembled seqeuntially that have different combination of options specified by customers. In just in time (JIT) environment, production smoothing becomes an important issue for sub-lines which supply the necessary parts to each workstation of the assembly line. Another important issue is to avoid line stopping caused by work overload in workstations. To find a sequence which minimizes the costs associated with line stoppage and the option parts inventory level, a nonlinear mixed integer programming is formulated. Recognizing the limit of the Branch and Bound technique in large sized problems, a heuristic solution procedure is proposed. The performance of the heuristic is compared with the Branch and Bound technique through randomly generated test problems. The computational results indicate that on the average the heuristic solutions deviate approximately 3.6% from the optimal solutions.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.32-32
• /
• 2003

In the neuron, SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) assembly plays a central role in driving membrane fusion, a required process for neurotransmitter release. In the cytoplasm, vesicular SNARE VAMP2 (vesicle-associated membrane protein 2) engages with two plasma membrane SNAREs syntaxin 1A and SNAP-25 (synaptosome-associated protein of 25 kDa) to form the core complex that bridges two membranes. While various factors regulate SNARE assembly, the membrane also plays the regulatory role by trapping VAMP2 in the membrane. The fluorescence and EPR analyses revealed that the insertion of seven C-terminal core-forming residues into the membrane controls complex formation of the entire core region, even though preceding 54 core-forming residues are fully exposed and freely moving. When two interfacial Trp residues in this region were replaced with hydrophilic serine residues, the mutation supported rapid complex formation.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.1
• /
• pp.142-147
• /
• 2014

Finite element analysis along with DOE scheme has been performed to obtain robust design of connecting rod assembly. An analysis was conducted with five loading steps. Fatigue analysis was done using commercial software FEMFAT and fatigue safety factors at the interested regions such as shank area of small end and big end were calculated. 27 design cases using 3 factors with 3 levels are constructed by design of experiment. Each case is simulated to find the most influential factors. Response for this study, maximum Von-Mises stress, has been used to determine main factors of connecting rod assembly. Among the 3 factors, compression load affected the response greatly. However, bolt assembly load and width of shank flat area showed a little influence to the response. Interaction effects among factors considered did not occur. Connecting rod assembly considered in this study showed its sensitivity to the noise factor such as compression load rather than design factor such as width of flat shank area.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.2
• /
• pp.183-192
• /
• 2006

Predicting energy expenditure (EE) is important to prevent work-related musculoskeletal disorders (WMSDs). The problem to predict EE is that the standard of EE is based on western data. The authors checked average EE by job categories to provide basic data for suggesting proper work intensity for Korean workers. This study was conducted from 2003 to 2005. Study subjects were recruited from 4 car parts assembly plant, 2 car assembly plant, 2 Heavy machine manufacturing plant and 2 shipyards. Total study subjects were 515 male workers. To estimate VO2max, sub-maximal test was conducted to measure VO275%max by bicycle ergometer (Combi Co, Aerobike 75XL II). Heartbeats were recorded with heartbeat recorder (Polar Electro Co, Finland, S810) during work. EE of work was calculated by recorded heartbeat and individual regression equation which was derived from sub-maximal test. Subjects were classified into 4 industry and 8 work posture, 23 job task categories. Mean EEs (S.D.) according to industry classification (kcal/min) were 4.9 (0.7), 4.8 (0.7), 4.9 (0.7), 5.0 (0.9), and 4.0 (0.5) for Car Part manufacture, Car Assembly, Ship Building, Heavy Machinery Manufacture, and Hospital Office, respectively. The results suggest that Korean male workers of exceeding to the NIOSH criteria will be needed to plan for job rescheduling to maintain $worker^{\circ}$Øs health. Further study to establish Korean work intensity standard would be needed.

• Korean Journal of Legislative Studies
• /
• v.22 no.2
• /
• pp.77-112
• /
• 2016

Given the few studies on the responsibilities of assembly, government, and president for social conflicts, this study analyzes the influence of conflict causes upon that responsibilities. First, the need for the mediation mechanisms for dealing with social conflicts and the level of labor-management conflict are positively associated with the responsibilities of assembly, government, and president. Second, the levels of conflict between social strata and ideological conflict are positively related with the responsibility of assembly or president. Third, interdependence and mutual understanding between stakeholder, among independent variables, are positively associated with the responsibilities of assembly and president. Finally, all of the levels of conflict types, except the level of ideological conflict, moderate the effects of conflict causes on the responsibilities of assembly, government, and president. These results reflect the importance of managerial and institutional approaches to the conflict resolution focused on conflict causes and types.

• Journal of Biosystems Engineering
• /
• v.32 no.3
• /
• pp.153-159
• /
• 2007

This study was conducted to measure and analyze the noise from a combine head. The combine head, comprised of a cutting knife assembly, pick-up chains, horizontally conveying chains and vertically conveying chains, had an overall sound level of 101 dBA. The sound levels of each component were, respectively, 98.3 dBA for the cutting knife assembly, 88.9 dBA for the pick-up chains, 79.8 dBA for the horizontally conveying chains and 86.3 dBA for the vertically conveying chains, being equivalent to 54.4%, 18.4%, 6.5% and 13.7% of the overall head noise. The main cause of the head noise was considered the impacts that the joint of the cutting knife assembly made with frame when it oscillated. The impact sound was also generated when the chain lug collided with the chain case. To reduce these impact sound, anti-vibration rubbers were installed on the knife assembly joint and the chain cases. It reduced the head noise by 4 dBA but the overall noise level of the combine head was still high. In order to protect the combine operators more effectively from the noise, a safety cab needs to be installed on the combine.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.169-171
• /
• 2007

A breaking layer was introduced to conventional decal transfer method in membrane electrolyte assembly fabrication for high catalyst transfer ratio. In this study, the modified decal transfer method with high catalyst transfer ratio was introduced and its performance is studied. The structural features of electrodes made by decal method were investigated using scanning electron microscopy and current-voltage polarization measurement.

• 축산식품과학과 산업
• /
• v.8 no.1
• /
• pp.74-77
• /
• 2019

• Korean Architects
• /
• s.655
• /
• pp.18-21
• /
• 2023

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.120.1-120.1
• /
• 2014

Fast-steering Secondary Mirror prototype (FSMP) of the Giant Magellan Telescope (GMT) has been developed by the consortium consisting of institutes in Korea and the US. In 2014 we are finalizing the FSMP project as combining two sub-systems, the mirror fabricated by Korea Research Institute of Standards and Science (KRISS) and the mirror cell with tip-tilt controlling system developed by Institute for Advanced Engineering (IAE), in the KRISS facility. In the assembly process we will identify potential difficulties or problems for the process, such that this process can be reflected to the further development of the FSM for GMT. In the presentation, we present how the assembly process can be carried out in safety.