• Korean System Dynamics Review
• /
• v.12 no.3
• /
• pp.67-86
• /
• 2011

This study shows the reduction effect of freight volume by the supply chain redesign for the alliance of distributors with system dynamics simulation. The as-is model is composed of 3 independent companies which one has 3 distribution centers (DCS) and 24 agents, another has 1 dc and 9 agents, the other has 3 DCS and 15 agents each. The to-be model is an integrated logistics model and composed of 1 company having 5 areal DCS and 38 agents. Each agent in the same area is integrated with each other. Two models have same demands but very different result. As a result, the freight volume between DCS and agents is reduced by 33.55%. This case study will be useful to analyze the similar cases about the logistics integration by supply chain redesign.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.160-161
• /
• 2006

Seasonal changes have been recognized in particle characteristics and forming characteristics of iron powder with insulated coating for a compacted magnetic core because of its high hygroscopicity, due to its phosphate coating and resin binder additives. For this reason, particle characteristics and molding characteristics of the powder with diverse water absorbtivity have been studied. The result shows that the higher the volume of absorbed water, the worse the fluidity becomes, resulting in the reduction in both springback during the molding process and expansion reduction after the heat treatment. The requirement on dimension accuracy for the finished product can be satisfied with an additional drying process on the material powder, which contributes to maintain its water volume constant.

• Progress in Superconductivity and Cryogenics
• /
• v.23 no.3
• /
• pp.26-31
• /
• 2021

Advanced classification of Cs contaminated soil by using a magnetic force-assisted selection pipe was investigated. A selection pipe is a device that sort particles depending on their particle size, based on the relationship between buoyancy, drag, and gravity force acting on the particles. Radioactive cesium is concentrated in small-particle size soil components with a large specific surface area. Hence, the volume of the Cs contaminated soil can be reduced by recycling the large-particle size soil components with low radioactive concentration. One of the problems of the selection pipe was that the radioactive concentration of the stayed soil in the selection pipe exceeds 8000 Bq/kg, which is the standard value of recycling of Cs contaminated soil, due to low classification accuracy. In this study, magnetic fields were applied to the lab-scale selection pipe from upper side to improve the classification accuracy and to reduce the radioactive concentration of the stayed soil.

• Journal of Chest Surgery
• /
• v.47 no.4
• /
• pp.358-366
• /
• 2014

Background: To improve sinus rhythm conversion, the Cox maze III procedure with narrow mazes (width: ${\leq}3.0cm$) was performed in combination with left atrial volume reduction. Methods: From October 2007 to April 2013, 87 patients with atrial fibrillation (paroxysmal in 3, persistent in 14, and permanent in 70) underwent the Cox maze procedure concomitant with another cardiac procedure. They were followed-up with serial electrocardiographic and echocardiographic studies. We used 24-hour Holter monitoring tests to evaluate postoperatively symptomatic patients. Results: At the mean follow-up time of 36.4 months, 81 patients (94.2%) had sinus rhythm and two were on anti-arrhythmic medication (one on a beta-blocker and the other on amiodarone). Five patients (5.8%) with postoperative recurrent and persistent atrial fibrillation never experienced sinus rhythm conversion; however, they did not require any medication for rate control. On postoperative echocardiography, the left atrial A waves were more frequently observed after concomitant mitral valve repair than after concomitant mitral valve replacement (82.4% vs. 40.4%, respectively; p<0.001). Conclusion: For the Cox maze procedure, narrow mazes and atrial volume reduction resulted in excellent sinus rhythm conversion without the preventive use of anti-arrhythmic drugs, and they did not affect the presence of the left atrial A waves on echocardiography.

• Journal of Korean Society of Water and Wastewater
• /
• v.32 no.3
• /
• pp.269-277
• /
• 2018

Burials for the rapid disposal of carcasses have diverse and profound effects on the rural living condition, natural environment, and local economy throughout construction, management and final destruction of burials. In this study, possible residue excavated from standard burials, storage using FRP (Fiberglass Reinforced Plastic) tanks, and microbial-treated burials are characterized as carcasses, contaminated soil by leachate, and wasted plastic film. Treatment technologies for volume reduction of the residue including composting, rendering, and thermal hydrolysis were investigated. If the solid and liquid residues generated during volume reduction treatment are directly transferred to the environmental facilities, it may cause disorder due to high concentrations of organics, antibiotics, and lipid. Benefits and drawbacks of composting as a volume reduction techniques are extensively investigated. We also discussed that proper treatment of excavated soils and the reusing the treated soil as agricultural purpose. For the protection of public health and worker's hygiene, treatment criteria including produced residue qualities, and quality standards for the treated soil as agricultural use are required. In addition, Scientific manual for the proper treatment of residues is required. It is necessary to consider the establishment of a pretreatment facility to the occurrence of large-scale residue treatment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.15 no.2
• /
• pp.181-189
• /
• 2017

The purpose of this paper is to evaluate several leading options for the management of radioactive metallic waste against a set of general criteria including safety, cost effectiveness, radiological dose to workers and volume reduction. Several options for managing metallic waste generated from decommissioning are evaluated in this paper. These options include free release, controlled reuse, and direct disposal of radioactive metallic waste. Each of these options may involve treatment of the metal waste for volume reduction by physical cutting or melting. A multi-criteria decision analysis was performed using the Analytic Hierarchy Process (AHP) to rank the options. Melting radioactive metallic waste to produce metal ingots with controlled reuse or free release is found to be the most effective option.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.5 no.2
• /
• pp.35-40
• /
• 2002

By the introduction of cleaning and drying processes, thermal extrusion system for the volume reduction of used polystyrene buoys was developed. It was tested in the costal area for the determination of operational reliability. By the removal of oyster shells and cleaning of salt, waste polystyrene buoys was changed to the raw material of plastics. The lower cost of one-tenth compared with that of the outer request treatment is promising the practical use of waste buoys' volume reduction system.

• Nuclear Engineering and Technology
• /
• v.21 no.4
• /
• pp.321-331
• /
• 1989

A bench scale incineration process for the burnable radwaste has been constructed and operated at KAERI as a self-surpported development of incineration technology. The purposes of operating the process are to get experience in incineration, to analyze the characteristics of combustion and to test the performance of off-gas treatment units. Simulated paper and polyethylene wastes were incinerated. Volume reduction ratio and decontamination factor of the process have been determined to observe the economical efficiency and operational capability of the process. A methodology to estimate the acceptance limit of specific activity to an incineration facility by using a decontamination factor and to calculate the volume reduction ratio of the facility is introduced. The acceptance criteria for different radionuclides in the combustible waste at the bench scale incineration process are suggested using this methodology.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 1999.11a
• /
• pp.68-72
• /
• 1999

In an effort to construct a structure under the design principle of minimal use of materials for maximum performances, a discrete gradient structure has been introduced in laminate composite systems. Using a sequential linear programming method, the gradient structure of composites to maximize the buckling load was optimized in terms of fiber volume fraction and thickness of each layer. Theoretical optimization results were then verified with experimental ones. The buckling load of laminate composite showed maximum value with the outmost [$0^{\circ}$] layer concentrated by almost all the fibers when the ratio of length to width(aspect ratio) was less than 1.0. But when the aspect ratio was 2.0, the optimum was determined in a structure where the thickness and fiber volume fraction were well balanced in each layer. From the optimization of gradient structure, the optimal fiber volume fraction and thickness of each layer were proposed. Experimental results agreed well with the theoretical ones. Gradient structures have also shown an advantage in the weight reduction of composites compared with the conventional homogeneous structures.

• Journal of International Society for Simulation Surgery
• /
• v.1 no.2
• /
• pp.71-74
• /
• 2014

Purpose The prominent mandible angle, otherwise known as "square face", has been recognized as an aesthetic problem that needs correction by many in the Asian community. Many surgeons considered that mandible angle ostectomy alone, brings about hypotrophy of the masseter muscle. However, it was only proven indirectly (by clinical experience and histological animal experiments) and not objectively. In this study, we evaluated the volume of masseter muscle to prove the effect, objectively. Materials and method Computed tomography (CT) images were used to measure the masseter muscle volume of normal female group (n=6), and of female patient group n=8, preoperative and early & late postoperative volumes) presenting the symptom of prominent mandible angle. The data was analyzed statistically by two-sample t-test and paired t-test using SAS (version 8.2). Results In normal female group, volume average was $16,142{\pm}2,829.8mm^3$. In patient group, preoperative volume averaged $24,447{\pm}4,544.5mm^3$ (p<0.0001), early postoperative volume measured average of $31,966{\pm}50,421mm^3$ which is a 30% increase from the preoperative volume (p<0.0001). Late postoperative measurement was $20,202{\pm}4,092.3mm^3$, which is a 20% decrease from the preoperative volume (p<0.0006). Conclusion The bone reduction of prominent mandible angle induce the hypotrophic effect of masseter muscle after long term follow up (5 more months). This result mean that the result of mandible angle contouring surgery can be considered as combined effect of bony angle reduction and subsequent masseter muscle hypotrophy.