• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.331-344
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• 2007

This study was performed to improve the hospital food service in quality and customer satisfaction by using 6-sigma strategy which was processed by DMAIC methods. The research procedure was as follows; analyzing the main causes of customer dissatisfaction of food service by using numerical method, and then finding out the standardized problem solving methods, and finally reforming food service process. The effectiveness of 6-sigma activity was measured by ‘food service quality index’, ‘customer satisfaction index’ and ‘total food service satisfaction index’. Food service quality index was calculated by adding grade of soup temperature, food service, delivery time, and setting accuracy. Statistical data analyses were completed by using the Minitab Ver. 14. By performing 6 sigma activity, food service quality index was increased from 67 to 79 points (p<0.05) and customer satisfaction index also rise from 73 to 79points (p<0.05). Satisfaction of meals’ taste, diverse menu, food setting accuracy, remove of food service, overall food service were significantly improved(p<0.05). The results of capability analysis in food service quality index, customer satisfaction index, and total food service satisfaction index were improved 2.11$\sigma$ to 2.49$\sigma$, 1.88$\sigma$ to 2.43$\sigma$, and 2.04$\sigma$ to 2.47$\sigma$ respectively (p<0.05). Therefore this study showed that subjective food service improving process could be measured by objective numerical value which might be used for financial value in hospital management.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.88-98
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• 2007

The control of nonpoint source pollution from the urban paved areas with high imperviousness in is required to improve the water quality of aquatic resources. This research investigated the characteristics of urban runoffs and evaluate the effectiveness of the continuous deflective separation systems for stormwater best management practice. The systems were installed in the vicinity of a high-level road, an apartment complex, and the Cheonggye stream. Stormwater runoff was sampled in these sites. Biochemical oxygen demand ($BOD_5$), total suspended solid (TSS), total nitrogen (T-N), and total phosphorus (T-P) were analyzed. The removal efficiency of $BOD_5$, TSS, and T-P for the road was 10.9-81.0%, 11.7-93.4%, 0-37.5%, respectively. That of $BOD_5$, TSS, T-N, and T-P for the complex was 12.5-65.8%, 26.5-77.6%, 1.8-28.7%, and 20.0-37.5%, respectively. The abatement efficiency $BOD_5$, TSS, T-N, and T-P for the stream was 7.2-85.2%, 41.7-98.2%, 11.3-65.6%, and 2.0-71.5%, respectively. This study shows that the systems can be used to remove $BOD_5$ and TSS from urban runoffs efficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.759-761
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• 2016

Recent changes in the information security environment have led to persistent attacks on intelligent assets such as cyber security breaches, leakage of confidential information, and global security threats. Since existing information security systems are not adequate for Advanced Persistent Threat; APT attacks, bypassing attacks, and attacks on encryption packets, therefore, continuous monitoring is required to detect and protect against such attacks. Accordingly, this paper suggests an operation plan for managing an information security system to block the attack routes of advanced persistent threats. This is achieved with identifying the valuable assets for prevention control by establishing information control policies through analyzing the vulnerability and risks to remove potential hazard, as well as constructing detection control through controlling access to servers and conducting surveillance on encrypted communication, and enabling intelligent violation of response by having corrective control through packet tagging, platform security, system backups, and recovery.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.3
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• pp.153-165
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• 2021

The objective of this study was to provide basic data for the conservation of wetland ecosystems in the Civilian Control Zone and the management of Yongyangbo wetlands in South Korea. Yongyangbo wetlands have been designated as protected areas. A field survey was conducted across five sessions between April 2019 and August of 2019. A total of 248 taxa were identified during the survey, including 72 families, 163 genera, 230 species, 4 subspecies, and 14 varieties. Their life-forms were Th (therophytes) - R₅ (non-clonal form) - D₄ (clitochores) - e (erect form), with a disturbance index of 33.8%. Three taxa of rare plants were detected: Silene capitata Kom. and Polygonatum stenophyllum Maxim. known to be endangered species, and Aristolochia contorta Bunge, a least-concern species. S. capitata is a legally protected species designated as a Class II endangered species in South Korea. A total of 26 taxa of naturalized plants were observed, with a naturalization index of 10.5%. There was one endemic plant taxon (Salix koriyanagi Kimura ex Goerz). In terms of floristic target species, there was one taxon in class V, one taxon in Class IV, three taxa in Class III, five taxa in Class II, and seven taxa in Class I. Three invasive alien species (Ambrosia trifida L., Ambrosia artemisiifolia L., and Humulus japonicus Siebold & Zucc) were observed. For continuous conservation of Yongyangbo Wetlands, it is necessary to remove invasive alien plants and block the inflow of non-point pollutants.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.443-450
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• 2019

Thermal management is a critical issue for the development of high-performance electronic devices. In this paper, thermal conductivity values of mild steel and stainless steel(STS) are measured by light flash analysis(LFA) and dynamic thermal interface material(DynTIM) Tester. The shapes of samples for thermal property measurement are disc type with a diameter of 12.6 mm. For samples with different thickness, the thermal diffusivity and thermal conductivity are measured by LFA. For identical samples, the thermal resistance($R_{th}$) and thermal conductivity are measured using a DynTIM Tester. The thermal conductivity of samples with different thicknesses, measured by LFA, show similar values in a range of 5 %. However, the thermal conductivity of samples measured by DynTIM Tester show widely scattered values according to the application of thermal grease. When we use the thermal grease to remove air gaps, the thermal conductivity of samples measured by DynTIM Tester is larger than that measured by LFA. But, when we did not use thermal grease, the thermal conductivity of samples measured by DynTIM Tester is smaller than that measured by LFA. For the DynTIM Tester results, we also find that the slope of the graph of thermal resistance vs. thickness is affected by the usage of thermal grease. From this, we are able to conclude that the wide scattering of thermal conductivity for samples measured with the DynTIM Tester is caused by the change of slope in the graph of thermal resistance-thickness.

• Corrosion Science and Technology
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• v.22 no.3
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• pp.187-192
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• 2023

The use of biomass is increasing as a response to the convention on climate change. In Korea, a method applied to replace fossil fuels is using wood chips in a cogeneration plant. To remove air pollutants generated by burning wood chips, a selective denitrification facility (Selective catalytic reduction, SCR) is installed downstream. However, problems such as ash deposition and descaling of the equipment surface have been reported. The cause is thought to be unreacted ammonia slip caused by ammonia ions injected into the reducing agent and metal corrosion caused by an acidic environment. Element analysis confirmed that ash contained alkali metals and sulfur that could cause catalyst poisoning, leading to an increase in the size of ash particle and deposition. Measurement of the size of ash deposited inside the facility confirmed that the size of ash deposited on the catalyst was approximately three times larger than the size of generally formed ash. Therefore, it was concluded that a reduction in pore area of the catalyst by ash deposition on the surface of the catalyst could lead to a problem of increasing differential pressure in a denitrification facility.

• Clean Technology
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• v.17 no.1
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• pp.1-12
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• 2011

Scientists and engineers have altered the properties of materials such as metals, alloys, polymers, ceramics, and so on, to suit the ever changing needs of our society. Man-made engineering materials generally demonstrate excellent mechanical properties, which often tar exceed those of natural materials. However, all such engineering materials lack the ability of self-healing, i.e. the ability to remove or neutralize microcracks without intentional human interaction. The damage management paradigm observed in nature can be reproduced successfully in man-made engineering materials, provided the intrinsic character of the various types of engineering materials is taken into account. Various self-healing ptotocols that can be applied for the organic materials such as polymers, ionomers and composites can be developed by utilizing suitable chemical reactions and physical intermolecular interactions.

• Journal of the Korean GEO-environmental Society
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• v.15 no.11
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• pp.13-19
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• 2014

Permeable reactive barrier has been recognized as the one of representative methods for remediation of contaminated groundwater. Reactive barrier system containing two and more reactive materials can remove multiple contaminants such as nutritive salts and heavy metals. In this study, removal efficiency of multiple contaminants was evaluated when both zeolite and basic oxygen furnace slag were used as reactive materials. Sequential batch test which consists of two materials was performed to evaluate removal efficiency comparing the reaction order of them against nutritive slats including ammonium and phosphate and heavy metal including cadmium. As a result, zeolite-basic oxygen furnace slag sequence batch test showed the best efficiency for removal of multiple contaminants including nutritive salts and heavy metal.

• Journal of Chest Surgery
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• v.13 no.1
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• pp.77-81
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• 1980

We present one case of 26-year-old male having saddle block combined with mitral valvular disease [NYHA Class IV] with auricular fibrillation. The most common cause of emboli is atrial fibrillation. The clinical manifestations of saddle emboli are relatively slow due to development of collateral circulation and large size of lumen of the aorta. The 5month duration of saddle emboli in this case led to severe atrophic changes, coldness, peripheral cyanosis on the both lower extremities, and flexion deformity on the knee and ankle joint of the left lower extremity. We planned staged operation for the saddle block and for mitral stenoinsufficiency and tricuspid insufficiency, because of poor general condition of the patient. The thromboembolectomy of aortic bifurcation was performed through the transabdominal approach without trial of Fogarthy catheter embolectomy, because of expectation of the secondary inflammatory changes of the vessel wall and thrombi which was 3 cm X 1 cm X 0.5 cm in size with irregular surfaced solid in consistency. 1 month later, after thromboembolectomy, mitral valve replacement and tricuspid annuloplasty were performed, with successful early operative result. During operation organized thrombi [1 cm X 0.5 cm] in the left auricle was removed. We wonder if simple management using Fogarthy catheter might be possible to remove the thromboemboli instead of thromboembolectomy by aortotomy in this case.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.718-731
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• 2003

SAN(Storage Area Network) was developed in response to the requirements of high availability of data, scalable growth, and system performance. In order to use the SAN more efficiently, most of the SAN operating software supports storage virtualization concepts that allow users to view physical storage devices of the SAN as a large volume. A logical volume manager plays a key role in storage virtualization. It realizes the storage virtualization by mapping logical addresses to physical addresses. In this paper, we design and implement an efficient and flexible mapping method for the logical volume manager. Additionally we also design and implement a free space management method for flexible mapping. Our mapping method supports a snapshot that preserves a volume image at certain time and on-line reorganization to allow users to add or remove storage devices to and from the SAN even while the system is running. To justify our mapping method, we compare it with the mapping method of the GFS (Global File System) through various experiments.