• Resources Recycling
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• v.7 no.3
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• pp.17-26
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• 1998

A study on the recovery of silver and nitric acid in the liquid waste resulted from the mediated electrochemical oxidation(MEO) process was conducted. The removal of silver in the concentrated nitric acid solutions was carried out by the electrodeposition. The removal efficiency more than 98% could be obtained in nitric acid concentrations less than 3 M with the current efficiency of nearly 100%. The experimonts on the evaporation for the recovery of nitric acid were performed as well. At the evaporation factor of 25., the degree of nitric acid recovery in 3.5 M nitric acid solution containing 0.5 to 1.0 mol% NaNO, was 80~90% resulting in 2.8~3.1 M nitric acid. The design factors and operating conditions of the distillation tower were analyzed by using MEH model derived by Maphtali-Sandholm with the throughput of 4 kg/hr for the enrichment of dilute nitric acid solution recovered by evaporation to reuse in the MEO process. The distillation column composed of eleven theoretical stages having the overall tray efficiency of 70% are needed to obtain 1.03 kg/h of 12M nitric acid and 2.97 kg/h of water with feed being introduced to the column at tray 6 from the bottom at the reflux ratio of 0.25, the reboiler with the heat load of 2.7 kW, and the condenser with the cooling load of 0.5 kW.

• Journal of the Korean Institute of Gas
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• v.24 no.4
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• pp.62-72
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• 2020

This study presents a methodology of history matching to evaluate the productivity of shale gas reservoir with high reliability and predict future production rate in the Horn-River basin, Canada. Sensitivity analysis was performed to analyze the effect of physical properties of shale gas reservoir on productivity. Based on the results, reservoir properties were classified into 4 cases and history matching were performed considering the classified 4 cases as objective function. The blind test was conducted using additional field production data for 3 years after the history matching period. The error of gas production rate in Case 1(all reservoir parameters), Case 2(influenced parameters for productivity), Case 3(controllable parameters), and Case 4(uncontrollable parameters) were 7.67%, 7.13%, 17.54%, and 10.04%, respectively. This means that it seems to be effective to consider all reservoir parameters in early period for 4 years but Case 2 which considered influenced parameters for productivity shows the highest reliability in predicting future production. The estimated ultimate recovery (EUR) of production well predicted using the Case 2 model was estimated to be 17.24 Bcf by December 2030 and the recovery factor compared to original gas in place (OGIP) was 32.2%.

• Korean Security Journal
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• no.16
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• pp.243-264
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• 2008

Investigation about training of Private Security in Korea has managed status of training and understanding of issue mostly, systematic analysis about transfer effect as well as learning and determinant of training is insufficient. Consequently this investigation research to examine the effect of training program for newly appointed private security guards to learning and transfer then, to analyze factor through incumbent private security guard-oriented hypothesis testing under article 13, section 1 of the security guard law. To grasp effect factors of learning and transfer, this dissertation establishes research model and research hypothesis through domestic and foreign studies and then theoretical as well as positive literatures consideration in the first place. Conclusion of this investigation through techniques mentioned above and data analysis is as follows. First of all, the personal characteristics, training characteristics, work environment, difference of transfer as well as learning are verified in accordance with Sociodemographic characterist of Private Security Guard. After then, there is a difference of great import. Secondly, the effect of personal characteristics of Private Security Guard to the transfer is inspected. As a result, there is a difference of significance statistical. Thirdly, the effect of training characteristics of Private Security Guard to the transfer is inspected. Consequently, there is a difference of import statistical. The following thing, subsequent to inspection about the effect of work environment of Private Security Guard to transfer, statistical difference of import is.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.160-166
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• 2010

A homothallic filamentous fungus Aspergillus nidulans has been used as the a model organism for studying growth and development for eukaryotic system. Various studies about specific transcription factors have been performed for elucidating the molecular mechanisms of growth, asexual and sexual developmental processes. Among them, the fkhE gene (AN2025.3) is located in chromosome VII and contains an ORF encoding 718 amino acid polypeptide intervening with two short introns. The cDNA sequencing revealed that at least four types of alternative splicing events were occurred when the fkhE gene was transcribed. The putative FkhE polypeptide contains a conserved forkhead domain and a bipartite nuclear localization signal at it's N-terminus and C-terminus, respectively. Deletion of fkhE resulted in impaired conidiophore formation in a solid medium. However, the sexual developmental process or cleistothecia formation was normal. Furthermore, fkhE deletion mutant produced conidiophores and conidia under the submerged culture, indicating that the fkhE gene is involved in asexual developmental process similar to the fkhF gene.

• International Journal of Quality Innovation
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• v.8 no.1
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• pp.40-75
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• 2007

In the early industrial age which with high intensity of machine and labor, using financial measurement index was good enough to tie in company's mechanization and philosophy of management and been in efficiency. But being comply with "New Economic age," a new economic environment is full of knowledge and information, the enterprise competition had changed from tangible assets, plants to intangible innovation ability of knowledge. As recognizing the new tendency by enterprise, they value gradually the growth and influence from learning. Practice of organization learning not only needs firm structure and be in coordination with both hardware and software, but also needs an affect measurement model to offer enterprise to estimate learning performance. It's a good instrument of financial performance measure mold in the past years, But it's for measuring the past, couldn't formulate enterprise trend to future, hard to estimate investment for future, such as development of products, organization learning, knowledge management etc, as which intangible assets and knowledge ability just the key factors of being win around competition environment in the future. In 1992, Kaplan and Norton brought up Balance Scorecard (BSC) on Harvard Business Review, as an instrument helping enterprise to measure performance, which is being considered to be a most influence management instrument. It added non-financial index such as customer, internal process and learning growth besides traditional financial index, as offering enterprise an index to measure and manage intangible assets and intellectual property. As being aware of organization learning is hard to be ignored in the new economic age, this research is based on learning and growth of BSC, and citing one national material company try to let the most difficult measurement performance of organization learning, to be estimate through BSC, analyze of factor and individual case, to discuss the company how to make the related strategy and vision of organization learning to develop learning and growth of the structure of BSC, subject the matter of out put factors to be discussed, and measure the outcomes as a result of research. The research affect offers (1) the base implement procedure of carrying out BSC; (2) the reference of formulating measurement index while enterprise using BSC to estimate performance of organization learning; (3) the possibility bottleneck maybe forcing while carrying out BSC, to be an improvement or preventive for enterprise.

• Journal of Korea Water Resources Association
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• v.51 no.7
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• pp.543-554
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• 2018

A methodology has been presented for evaluating the partial safety factors on the sliding failure mode of vertical caissons of composite breakwaters and for determining the cross sections of those by Level I reliability-based design method. Especially, a mathematical model has been suggested for the sake of a consistency of code format as well as convenience of application in practical design, for which the uncertainties associated with buoyancy and its own weight can be taken into account straightforwardly. Furthermore, design criteria equation has been derived by considering accurately the effect of uplift pressure, so that the cross sections of caissons can be assessed which must be safe against the sliding failure. It has been found that cross sections estimated from partial safety factors proposed in this paper are in very good agreement with the results of Level II AFDA and Level III MCS under the same target probability of failure. However, partial safety factors of the Technical Standards and Commentaries for Port and Harbour Facilities in Japan and Coastal Engineering Manual in USA tend to estimate much bigger or smaller cross sections in comparison to the present results. Finally, many reliability re-analyses have been performed in order to conform whether the stability level of cross section estimated by Level I reliability-based design method is satisfied with the target probability of failure of partial safety factors or not.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.197-209
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• 2017

With the advent of age that people spend more time and money on leisure activities, there is increasing interest in professional sport games. The location of large scale sport facilities has substantial impacts on existing transportation pattern because the facility attracts and generates massive traffic volume within a short period of time. This study aims to develop a mode choice model of leisure trips of which the destinations are a sport facility. A structured SP (stated preference) survey questionnaires were developed through an experimental design, and professional sport spectators were asked to state their preference in the choice of transport mode to the sport facility. The survey results show that public transportation is preferred to passenger cars for their trip to big sports event, implying that the convenience of back home trip after the event is an important factor of their mode choice. This study is a rare research on the trip pattern to sports complex in Korea, which provides policy implications on the provision of mass transit including subway system to large scale sport complexes. And it is also expected that this study contributes to future researches on leisure trip pattern.

• Journal of Veterinary Clinics
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• v.32 no.4
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• pp.324-329
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• 2015

The primary aim of this study was to investigate biosecurity practices in pig farms and to determine the major risk factors associated with PCV2 infection for a sampled swine population in Korea. To this end, we analyzed data from a cross-sectional study of 296 farrow-to-finish farms, which was conducted between March and September 2014 to explore the prevalence of swine disease at farm level. Face-to-face interviews by on-site visit of trained veterinarians were conducted with the farm owners or managers using a standardized questionnaires with information about basic demographical data and management practices. Farms were classified as negative or positive through the use of infection profiles that combined data on serological testing including PCR antigen test result, antibody titer and sero-conversion pattern at each age category taking into account vaccination status. Data were analyzed using multivariate ordinal logistic regression. Results from this study indicated that biosecurity level of the farms was considered not good given low compliance of the biosecurity programs and facilities in the farm: off-site removal of dead stocks (7%), off-site location of storage facility for incoming feeds (12.6%), off-site pick-up location for finishers (19.3%), restrictions on feed supplier vehicles for farm entrance (19.6%), restriction of finisher trucks entering the farm (22.4%), and restriction on manure disposal trucks entering the farm (26.4%). In the final model (n = 255), allowance of finisher truck driver to the pig unit had increased risk of infection (OR = 2.4, 95% CI 1.22-4.67) whereas farms with a sign forbidding the entrance had decreased risk of infection (OR = 0.19, 95% CI 0.10-0.58). Further comprehensive research with larger sample size is required to better understand the multifactorial characteristic that some predisposing risk factors that were not available in this study. To the best knowledge of the authors, this was the first study to use empirical data to report risk factors associated with PCV2 infection in the Korean pig farms. Results from the current study could be used to decide optimal biosecurity measures to reduce the impact of PCV2 infection to farmers and policy makers.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.1
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• pp.174-180
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• 2006

We examine the effect of Geiji-Bokryung-Hwan(GBH) on erectile function in a rat model of hypercholesterolemic erectile dysfunction. GBH, a drug preparation consisting of five herbs of Cinnamomi Ramulus (Geiji), Poria Cocos (Bokryun), Mountan Cortex Radicis (Mokdanpi), Paeoniae Radix (Jakyak), and Persicae Semen (Doin) is a traditional Korean herbal medicine that is widely used in the treatment of atherosclerosis-related disorders. In this study, 3-month-old Sprague-Dawley rats were used. The 6 rats control animals were fed a normal diet and the other 18 rats were fed 1% cholesterol diet for 3 months. After 1 months, GBH was added to the drinking water of the treatment group of 12 rats but not the cholesterol only group of 6 rats. Of the 12 rats 6 received 30 mg/kg per day (group 1) and 6 received 60 mg/kg per day (group 2) of GBH. At 3 months erectile function was evaluated with cavernous nerve electrostimulation in all animals. Penile tissues were collected for electron microscopy, and to perform Western blot for endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), basic fibroblast growth factor (bFGF) and caveolin-1. Systemic arterial pressure was not significantly different between the animals that were fed the 1% cholesterol diet and the controls. Conversely erectile function was not impaired in the herbal medicine treated rats. Electron microscopy showed many caveolae with fingerlike processes in the cavernous smooth muscle and endothelial cell membranes in control and treated rats but not in the cholesterol only group of rats. Western blot showed differences among groups in protein expression for eNOS, nNOS, caveolin-1 and bFGF protein expression in penile tissue. Increased eNOS and nNOS protein expressions dy high cholesterol diet were significantly decreased in group 1 and group 2. Interestingly, caveolin-1 and bFGF protein expression was significantly higher in groups 1 and 2 than in the cholesterol only and control groups.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.3
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• pp.164-176
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• 2016

This study was perfomed to investigate the effects of Chunghyul-plus(CHP) on oxidative damage and hyperlipidemia in db/db mouse. After treatment with CHP, safety in cytotoxicity, heavy metal toxicity, production of reactive oxygen species(ROS), nitric oxide (N0) and proinflammatory cytokine IL-Ib, TNF-a, IL-6 in RAW 264.7 cells. Serum total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, insulin, GLP-1, glucose, food intake, body weight, organ weight, AST, ALT, ALP, BUN, creatine and histologic change of liver and aorta were measured in db/db mouse after oral administration of CHP. CHP showed safety in cytotoxicity and toxicity of liver and kidney for logn time administration. CHP increased the DPPH and ABTS radical scavenging activity. CHP showed significant inhibitory effect on reactive oxygen species (ROS), and showed inhibitory effect on nitiric oxide(NO) compared to control group. CHP decreased cytokine IL-6 production significantly, and decreased IL-1β and TNF-α compared to control group. CHP decreased body and organ weitht, intake food, and glucose levels compared to control group. CHP decreased total cholesterol and triglyceride significantly, and decreased LDL-cholesterol levels and increased HDL-cholesterol levels compared to control group. CHP decreased atherogenic index and cardiac risk factor significantly. CHP increased serum insulin and GLP-1 compared to control group. In histologic examination, lipophagy in the liver and aorta decreased in CHP treated mice and the cell was regular and boundary of vessel wall was clear compared to control group. These results suggest that CHP is effective in antioxidation activity and treatment and prevention of hyperlipidemia, atherosclerosis, diabetes, ischemic heart disease, stroke and other cardiocerebrovascular disease.