• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.383-389
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• 2011

The purpose of this paper is to analyze the blind spot for public transportation by level of service(LOS) in public transportation supply service. For the purpose, we proposed indices of service coverage area, service frequency and hours of service and analysis method for them. Service coverage area analysis is to decide station location and network design for the maximum beneficiary area. Moreover, we can use the service frequency is for the maximum service frequency decision and hours of service is for the minimum operation hours. The results of this study are applied to the plan of minimum supply service, minimum service frequency and minimum operation hours for city and national public transportation plan.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.451-458
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• 2010

Unlike most aerodynamic wind-tunnel, Scramjet Engine Test Facility(SETF) of Korea Aerospace Research Institute should simulate enthalpy condition at a flight condition. SETF is a blow-down type, high-enthalpy wind tunnel. To attain a flight condition, a highly stagnated air comes into the test cell through a supersonic nozzle. Also, an air ejector of the SETF is used for simulating altitude conditions of the engine, and facility starting. SETF has a free-jet type test cell and this free-jet type test cell can simulate a boundary layer effect between an airplane and engine using facility nozzle, but it is too difficult to predict the nature of the facility. Therefore it is required to understand the starting characteristics of the facility by experiments. In this paper, the starting characteristics of the SETF and modifications of the ejector are described.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.556-566
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• 2019

Recently, as the supply of residential polymer electrolyte membrane fuel cells (PEMFCs) increases, the durability and lifetime of the PEMFC system are becoming important. The related studies have been mainly focused on the durability and lifetime of materials while the research on the durability and maintenance of the system level is insufficient. In this paper, a model-based fault detection method is developed considering an air supply system that is dominant to the system performance and efficiency. A commercial 1 kW residential fuel cell system is built, and experiments are conducted under various operation loads and states (normal, 6 faults). From the experimental data, nominal models and residuals are generated. With the residual pattern obtained from real-time data, the detection and classification of various faults can be possible. The technical importance of this paper is to minimize extra sensor installation by using the empirical model rather than a complex mathematical model, and to decrease the number of models by using the applicable model at three loads. Finally, the model-based fault detection method for the air supply system of a PEMFC is established and is expected to be applicable to other subsystems.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.73-77
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• 2022

Blood products (BPs) can only be obtained through blood donation and hence represent a finite resource. BPs should therefore be used conservatively. However, BPs are being used indiscriminately without evidence. The purpose of this study was to evaluate the reasons for the use of BPs and their appropriateness. The investigation was carried out based on hemoglobin levels. Data were obtained from Nov 1, 2020, to Oct 31, 2021, from a hospital's OCS/EMR systems. The BPs were dispensed in 21,303 cases, and the number of hemoglobin levels >7.0 g/dL or higher among red blood cell drugs used by each treatment department was 1,173 (>7.0 g/dL). The misuse of blood transfusions is increasing social costs, with the adequacy of transfusion becoming increasingly important. Hence, each medical institution should review the transfusion guideline evaluation index, check the status of the release of BPs, and institute educational programs covering transfusion guidelines and continually evaluate their adequacy.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.8-8
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• 2021

2020년 6월 발전용댐의 다목적활용 선포로 국내 발전용댐은 발전에 제한되었던 기능이 홍수조절, 용수공급, 환경개선 등으로 확장되었다. 특히 북한강 수계에는 화천댐부터 팔당댐까지 5개의 발전용댐이 직렬로 배치되어 있기 때문에 기능에 따른 통합연계운영은 해당 수계 내 수자원 활용의 효율성을 높여줄 것으로 기대되고 있다. 그러나, 발전용댐의 주요 목적인 발전과 부가 목적인 홍수조절 및 용수공급은 수자원 활용 측면에서 상반된 운영을 수행해야 하므로 효율성 측면에서 세심한 운영이 필요하다. 국내에는 과거 발전용댐의 운영과 관련한 많은 연구가 진행되어 왔고 최근에는 회복탄력성 개념을 도입하여 단일 발전용댐에 대한 운영방안을 제시하였다(Kim et al., 2020). 그러나 발전가능수위의 회복력으로 정의된 발전용댐의 회복탄력성은 직렬 배치되어 있을 경우 상·하류 상황에 따라 달라질 수 있다. 즉, 상·하류의 방류상황에 따라 단일 댐 혹은 수계 내 존재하는 발전용댐의 발전기능, 이수기능, 치수기능은 상호간섭 영향을 받게 된다. 따라서, 본 연구에서는 회복탄력성 개념을 직렬배치된 발전용댐에 적용하여 댐 연계운영방안을 제시하고자 한다. 과거 유입량 자료를 활용하여 발전용댐 연계 모의운영을 수행하였고, 그 결과로 수계 내 발전용댐 전체의 회복탄력성, 발전량, 홍수위험일수, 무효방류량 등을 평가하였다. 또한 단일 댐 운영과 비교하여 연계운영 효과에 대해 분석하였다. 향후 병렬배치의 댐 운영과 경제성 평가분석이 이뤄진다면 국내 한강수계 실정에 맞는 발전용댐 최적 운영기준을 제시할 수 있을 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.375-383
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• 2006

Nationals Assembly have experiencing unbalance between capacities and demand of parking facilities because of increasing parking demand, free parking policy, long term parking and passenger car use of workers, usage of neighborhood office workers and visitors. The lack of parking facilities cause illegal parking on the street inside and outside of National Assembly which result in the disorder of parking culture. To solve these parking problems, this study suggest parking management system to enter the National Assembly for the short term and charging parking fee, operation by private company, constructing parking building by abrogation of upper limit and construction of ground park, and so on. The study, also, suggested to strengthen weekday or 10 day shift system, to increase shuttle bus and commuting bus, to activation of Han River waterside parking area, public transportation with those new parking management system. For the conclusion, the parking problems of National Assembly should be focused more on parking management than the parking facilities supply.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.257-264
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• 2015

To determine whether metabolite fingerprinting for whole cell extracts based on Fourier transform infrared (FT-IR) spectroscopy can be used to discriminate and compare metabolic equivalence, standard medicinal parts from four medicinal plants (Cynanchum wilfordii Hemsley, Atractylodes japonica Koidz, Polygonum multiflorum Thunberg and Astragalus membranaceus Bunge) and their in vitro-produced adventitious roots were analyzed by FT-IR spectroscopy. The principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) from the FT-IR spectral data showed that the whole metabolic pattern from Cynanchum wilfordii was highly similar to Astragalus membranaceus. However, Atractylodes japonica and Polygonum multiflorum showed significantly different metabolic patterns. Furthermore, adventitious roots from Cynanchum wilfordii and Astragalus membranaceus also showed similar metabolic patterns compared to their standard medicinal parts. These results clearly show that mass proliferation of adventitious roots may be applied to aquire novel supply of standard medicinal parts from medicinal plants. However, the whole metabolic pattern from adventitious roots of Atractylodes japonica and Polygonum multiflorum were not similar to their standard medicinal parts. Furthermore, FT-IR spectroscopy combined with multivariate analyses established in this study may be applied as an alternative tool to discriminate the whole metabolic equivalence from several standard medicinal parts. Thus, we suggest that these metabolic discrimination systems may be applied for metabolic standardization of herbal medicinal resources.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.77-84
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• 2006

This study was conducted to find a system for screening organic resources with 16 species, 62 samples which were selected to randomizing point from city, province and industrial areas in the whole country. Content of organic matters were $65.3%{\sim}98.0%$ in all samples so that they were largely over than 60%, raw material regulation of compost. Concentrations of total nitrogen and total phosphorus were $0.7{\sim}4.8%\;and\;0.8{\sim}5.0$, they could look for effect of the nitrogen and phosphorus supply as a raw material of compost. In case of 8 elements concentrations of heavy metal, they were too high to use as raw materials of compost which were over to regulation limit in Cu, Cr, Ni, and As from fiber industry, Ni from food company and leather industry, and the others are adapt to limit levels. HEM contents fro the highest to $113mg\;kg^{-1}$ from liber industry and PAHs content were the highest to $3,462ug\;kg^{-1}$ from paper-mill manufacture. Distribution of PAHs concentiations were naphthalene>phenanthrene>pyrene>fluoroanthene>acenaphthene. $Microtox{(R)}\;EC_{50}$ values for bioassay were pharmaceutical company>paper-mill manufacture>industrial area sewage sludge>fiber industry>urban sewage sludge>metropolitan sewage sludge. HEM between Zn, Cu, and Ni was significant at the 99% and between Cd was significant at the 95%, Microtox between Hg and BEM significant at the 95%.

• Clean Technology
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• v.19 no.3
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• pp.313-319
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• 2013

To produce biodiesel efficiently from fish oil containing 4% free fatty acid, esterification and trans-esterification were carried out with Vietnam catfish oil, which was kindly provided from GS-bio company. Heterogeneous solid acid catalysts such as Amberlyst-15 and Amberlyst BD-20 and sulfuric acid as homogeneous acid catalyst were used for the esterification of free fatty acids in the fish oil. Sulfuric acid showed the highest removal efficiency of free fatty acid and the shortest reaction time among three acid catalysts. The base catalysts for trans-esterification such as KOH, $NaOCH_3$ and NaOH were compared with each other and KOH was determined to be the best transesterification catalyst. Some solid material, which assumed to be saponified product from glycerol and biodiesel, were observed to form in the fish oil biodiesel when using $NaOCH_3$ and NaOH as the transesterification catalyst. The initial acid value of fish oil was proven to have a negative effect on biodiesel conversion. Of the three catalysts, KOH catalyst transesterification was shown to have high content of FAME and the optimal ratio of methanol/oil ratio was identified to be 9:1.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.164-176
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• 2019

For this study, we carried out a field survey on the analysis for the spatial distributions of phytoplankton community in the eleven areas of the Korean South Sea during the early summer of 2018. The results from the study showed that the phytoplankton community consisted of 56 genera and 105 species showing by diatoms with 52.4%, dinoflagellates with 40.0% and other phytoflagellates with 7.6%. The cell density of the phytoplankton ranged from 5.5 to 593.2 cells mL^-1. The species number and cell density of the phytoplankton were high in the eastern waters of the South Sea and low in the western one. The phytoplankton community showed the characteristics of being dominated by the diatoms except in the Geumpo of Namhae, Ocheon-dong of Yeosu and Oenarodo of Goheung. The dominant species of the phytoplankton community were the centric diatoms, Skeletonema costatum-like species (ls), except for the Ocheon-dong and Chungdo of Wando. However, the Ocheon-dong was dominated by toxic dinoflagellate, Gymnodinium catenatum by 41.1% dominance. On the other hand, Keumpo and Oenarodo was by dinoflagellate, Tripos fusus more than 12% dominance in the surface layer. The spatial distribution of the phytoplankton community in the coastal waters of the Korean South Sea in the early summer were determined by the supply of nutrients through precipitation.