• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.102-111
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• 2010

Molten carbonate fuel cell (MCFC) power plants are one of most attractive electricity generation systems for the use of biogas to generate high-efficiency ultra-clean power. However, MCFCs are considerably more expensive than comparable conventional electricity generation systems. The commercialization of MCFCs has been delayed more than expected. After being effective in the Kyoto protocol and considerably increasing the fossil price, the attention focused on $CO_2$ regression and renewable energy sources has increased dramatically. In particular, the commercialization and application of MCFC systems fed with biogas have been revived because of the characteristics of $CO_2$ collection and fuel variety of MCFCs. Better economic results of MCFC systems fed with biogas are expected because biogas is a relatively inexpensive fuel compared to liquefied natural gas (LNG). However, the pretreatment cost is added when using anaerobic digester gas (ADG), one of the biogases, as a fuel of MCFC systems because it contains high $H_2S$ and other contaminants, which are harmful sources to the MCFC stack in ADG. Thus, an accurate economic analysis and comparison between MCFCs fed with biogas and LNG are very necessary before the installation of an MCFC system fed with biogas in a plant. In this paper, the economic analysis of an MCFC fed with ADG was carried out for various conditions of electricity and fuel price and compared with the case of an MCFC fed with LNG.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7B
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• pp.728-733
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• 2009

An ubiquitous environment has features like peer-to-peer and nomadic environments. Such features can be represented by peer-to-peer systems and mobile ad-hoc networks. P2P systems and MANETs share similar features, appealing for implementing P2P systems in MANET environment. However, if a P2P system designed for wired networks was applied to mobile ad-hoc environment, its performance was not good enough. Subsequently, this paper proposes a P2P system to improve performance using cross-layer design and the goodness of a node as a peer by using routing metric and P2P metric to choose favorable peers to connect. It also utilizes proactive approach for distributing peer information. The simulation results showed that the proposed system produced better performance in query success rate, query response time and energy consumption by reducing the routing path length.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.1
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• pp.1-10
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• 2007

The effects of mulberry-leaf powder Tofu(MPT) on anthropometric measurements, including bone mineral density(BMD) in the right carpus, biochemical bone turnover markers, serum levels of lipids and macrominerals, were investigated in 30 smoking male adults who lived in Choongnam were given MPT(100 g/day) for 4 weeks. The average ages, number of smoked cigarettes and packyear were 22.38 years, 15.12/day and 3.54 years, respectively. The nutrient contents per 100 g MPT were 86.10 kcal energy, 8.98 g protein, 0.53 mg fiber, 211.33 mg Ca and 1.59 g fat. Anthropometric measurements, including dietary intake using the 24-hours recall method, carpal BMD using DEXA, serum levels of protein, albumin and glucose, lipid profiles (cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) with Al(atherosclerosis index), HTR, CRF, LHBt, some biomarkers of BMD(serum alkaline phosphatase activity, osteocalcin, urinary DPD), and serum macrominerals(Ca, Ca/P ratio, Mg) and Pb were analyzed before and after consumption of MPT. After MPT consumption, dietary intakes of plant protein, total Ca and plant Ca increased significantly, but there were no significant differences in anthropometric measurements, BMD with bone metabolism markers, serum levels of protein, albumin or glucose, lipid profiles with AI, HTR, LHR and CRF.

• Journal of Korea Port Economic Association
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• v.26 no.4
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• pp.1-18
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• 2010

The purpose of this paper is to evaluate the green logistics of Korea enterprises. According to participate pan-nationally about environment problems, the field of logistics is required to transfer green logistics like increase efficiency of using energy and construct economic systems. And also environment-friendly policies of enterprises are playing important role. So authors selected and analysed factors through precedent study and questionnaire. Selected factors are cultivation about environment-friendly policy awareness to employees, Utilization environment-friendly resources, decrease of atmosphere pollution substance, company's promotion of outside environment-friendly policy. In order to shed light on these problem, fuzzy AHP method is adopted and the factor of cultivation about environment-friendly policy awareness to employees is the highest weight. And also result of the highest weight between enterprises that set policies about green logistics and factors' are The Korean Air, Glovis, Korea Express synthetically.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.6
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• pp.34-40
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• 1985

Characteristics of GaAE epilayers grown on (100) CaAs wa(tors by molecular beam epitaxy (MBE) under various single crystal growing conditions were investigated. In fabrica-ting GaAs, epilayer by MBE, the most important factors are a substrate temperature(ts) and a flux density ratio (As/Ga). In this experiment, the substrate temperature was varied in the range of 48$0^{\circ}C$ to $650^{\circ}C$ and As and Ga cell temperatures were varied in the range of 218$^{\circ}C$ to 256$^{\circ}C$ and 876$^{\circ}C$ to 98$0^{\circ}C$, respectively. At the substrate temperature of 54$0^{\circ}C$, As cell temperature of 23$0^{\circ}C$, and Ga cell temperature of 91$0^{\circ}C$, the As/Ga ratio was 5"10, the surface morphology was most smooth . Investigation of As-stabilized surface by RHEED and of depth profile by SIM5 showed that As is less stable than Ga. Also, X-ray diffraction measurement revealed that single crystals of (400) and (200) were formed at the both sub-strate temperatures of 52$0^{\circ}C$ and 54$0^{\circ}C$.TEX>.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.115.2-115.2
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• 2012

In this study we have used the data of various instruments onboard the THEMIS spacecraft to study the characteristics of the outer radiation belt during the ascending phase of solar cycle 24. The most astonishing result is that we discovered four long-term (a month or so) periods during which the belt has nearly disappeared. The first disappearance started late 2008, followed by reappearance in ~a month, and three more similar events repeated until early 2010 when the belt has reappeared. This is well revealed at 719 keV electrons, which is the currently available uppermost energy channel from the THEMIS SST observation, but also seen at even lower energies. Overall consistent features were confirmed using the NOAA-POES observations. The vanished belt periods are associated with extremely weak solar wind conditions, low geomagnetic disturbances (in terms of Kp and AE/AL), greatly suppressed wave (ULF and chorus) activities, greatly reduced storm and substorm activities (little source particle supply), and expanded plasmapause locations. The direct observations of such events shed light on the fundamental question of the origin of the radiation belt, which is the main focus of our presentation.

• Journal of Korean Biological Nursing Science
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• v.14 no.3
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• pp.183-192
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• 2012

Purpose: Number of the old-old elderly is rapidly increasing in Korea, but it is unclear whether there are differences between old-old and young-old elderly in nutritional status, nutrient intakes and health status. The gender differences in Korean elderly in these conditions also remains unknown. This study, therefore, investigated gender-associated differences in nutritional, health status and nutrient intakes and how they are related among young-old and old-old homebound elderly. Methods: Two hundred and eighty elderly who were attending a local elderly welfare center were recruited. Evaluation included demographic, nutritional and health status related data, nutritional intakes, and life style related factors including physical activity. Results: Of the 280 subjects, old-old were 147 (52.5%) and young-old were 133 (47.5%). Male old-old elderly had more often abdominal obesity than female old-old, but male old-old more often had malnutrition than female old-old. There were few differences in nutrient intakes between old-old male elderly and female elderly after energy intakes were controlled. Male old-old more often had less intake of beta carotene and Vitamin A than female old-old. On the other hand, male old-old elderly more often had hypercholesterolemia and hypertension than male young-old. Conclusion: Male old-old may be at a greater health and nutritional risk than female old-old. Targeted nutritional intervention for male old-old emphasizing antioxidant nutritional intakes may be warranted.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.408-416
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• 2001

Objectives : To evaluate the diagnostic value of quantitative ultrasound (QUS) in the prediction of osteoporosis as defined by dual energy x-ray absorptiometry (DEXA) in postmenopausal women. Methods : Questionnaires and height and weight measurements were used in the investigation of 176 postmenopausal women. QUS measurements were taken on the right calcaneus while bone mineral density (BMD) measurements of the lumbar spine and femoral neck were made with DEXA. The areas under the curves (AUC) of the speed of sound (SOS) for osteoporosis in the lumbar spine and femoral neck were obtained through receiver operating characteristic (ROC) analysis and evaluated. A comparison was made, for osteoporosis in the lumbar spine and femoral neck, between the AUCs of the logistic model with clinical risk factors and SOS. Results : Pearson's correlation coefficients of SOS and lumbar spine BMD, and of SOS and femoral neck BMD were 0.26 and 0.37. The AUC for the logistic model in its discrimination for lumbar spine osteoporosis was 0.764, and for SOS 0.605. The AUCs for the logistic model in its discrimination for femoral neck osteoporosis and for SOS were 0.890 and 0.892, respectively. Conclusions : These results suggest that the diagnostic value of QUS as a screening tool for osteoporosis is moderate for the femoral neck, but merely low for the lumbar spine and that the predictability provided by SOS is no better than that by the sole use of clinical risk factors in postmenopausal women.

• Journal of the Korean institute of surface engineering
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• v.51 no.4
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• pp.224-230
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• 2018

In this study, Mg films were prepared on hot dip aluminized steel (HDA) by using a sputtering method as a high corrosion resistance coating. The corrosion resistance of the Mg films was improved by controlling the morphology and the crystal structure of films by adjusting the Ar gas pressure during the coating process. Anodic polarization measurement results confirm that the corrosion resistance of the Mg films was affected by surface morphology and crystal structure. The corrosion resistance of the Mg coated HDA specimen increased with decreasing crystal size of the Mg coating and it was also improved by forming a film with denser morphology. The crystal structure oriented at Mg(101) plane showed the best corrosion resistance among crystal planes of the Mg metals, which is attributed to its relatively low surface energy. Neutral salt spray test confirmed that corrosion resistance of HDA can be greatly improved by Mg coating, which is superior to that of HDG (hot dip galvanized steel). The reason for the improvement of the corrosion resistance of Mg films on hot dip aluminized steel was due to the barrier effect by the Mg corrosion products formed by the corrosion of the Mg coating layer.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.117-124
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• 2019

Recently, medical IT solutions are being provided on a distributed environment basis. In Korea, the necessity of developing a clinical decision support system that can share medical information in a distributed environment has been recognized and studied. The existing clinical decision support system is being built using only medical information of its own within the hospital. This makes it difficult for existing systems to achieve good results in terms of efficiency and accuracy of decision support. In order to solve these limitations, this paper proposes a design and implementation method of clinical decision support system based on common data model in medical field. To explain the application process of the proposed model, we describe the development scenario of the clinical decision support system for the diagnosis of colorectal cancer. We also propose the essential requirements for the development of successful clinical decision support systems. Through this, it is expected that it will be possible to develop clinical decision support system that can be used in various hospitals and improve the efficiency and accuracy of the system.