• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.792-800
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• 2012

The study was performed to simulate the reduction efficiency of suspended solids (SS) for cultivated land located at riverine area at the Namhan River and the Bukhan River watershed sites (site A, B, C) under the rainfall conditions using HUFF & SCS UH-based VFS Design module of Web GIS-based VFSMOD System. The study indicates that the field 5% sloped, located at Bukhan River watershed (site A), requires at least 0.5 m width of Vegetative Filter Strip (VFS) to reduce 70% of SS while the field 10% sloped requires the at least 1.0~1.5 m width of VFS to reduce 70% SS, under the condition 106.2 mm of rainfall event and bell pepper or corn of crops. Against the conditions 95.1 mm of rainfall event and sweet potato or soy bean of crops, the field 5% sloped, located at Namhan River watershed (site B) requires at least 0.5 m width of VFS to reduce 70% of SS while the field 10% sloped requires at least 1.0 m width of VFS to reduce 50% SS. The crops sweet potato and soy bean are cultivated in the site C, located at Namhan River watershed, 1 m of VFS is capable of 64.0% and 62.0% of SS reduction against 102.6 mm and 151.2 mm rainfall conditions respectively, for the 5% sloped field. The result supports that VFS is one of most potential methods to reduce SS from cultivated area, which is environment-friendly hydrologic structure. The VFS design, however, needs to be simulated before its installation in the field, the simulation needs to consider not only various characteristics of the field but also different conditions affecting the VFS, using a model capable to consider a lot of factors.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.295-302
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• 2014

This study demonstrates a double-path CDI as an alternative of advanced wastewater treatment process. While the CDI typically consists of many pairs of electrodes connected in parallel, the new double-path CDI is designed to have series flow path by dividing the module into two stages. The CFD model showed that the double-path had uniform flow distribution with higher velocity and less dead zone compared with the single-path. However, the double-path was predicted to have higher pressure drop(0.7 bar) compared the single-path (0.4 bar). From the unit cell test, the highest TDS removal efficiencies of single- and double-path were up to 88% and 91%, respectively. The rate of increase in pressure drop with an increase of flow rate was higher in double-path than single-path. At 70 mL/min of flow rate, the pressure drop of double-path was 1.67 bar, which was two times higher than single-path. When the electrode spacing was increased from 100 to $200{\mu}m$, the pressure drop of double-path decreased from 1.67 to 0.87 bar, while there was little difference in TDS removal. When proto type double-path CDI was operated using sewage water, TDS, $NH_4{^+}$-N, $NO_3{^-}$-N and $PO_4{^{3-}}$-P removal efficiencies were up to 78%, 50%, 93% and 50%, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.980-990
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• 2004

In this paper, we propose the dynamic bandwidth allocation algorithm for the IEEE802.3ah Ethernet Passive Optical Network(EPON) system to provide the fairness among terminals, and evaluate the delay-throughput performance by simulation. For the conventional EPON systems, an Optical Line Termination (OLT) schedules the upstream bandwidth for each Optical Network Unit (ONU), based on its buffer state. This scheme can provide a fair bandwidth allocation for each ONU. However, it has a critical problem that it does not guarantee the fair bandwidth among terminals which are connected to ONUs. For an example, we assume that the traffic from a greedy terminal increases at a time. Then, the buffer state of its ONU is instantly reported to the OLT, and finally the OW can get more bandwidth. As a result, the less bandwidth is allocated to the other ONUs, and thus the transfer delay of terminals connected to the ONUs gets inevitably increased. Noting that this unfairness problem exists in the conventional EPON systems, we propose a fair bandwidth allocation scheme by OLT with considering the buffer state of ONU as welt as the number of terminals connected it. For the performance evaluation, we develop the EPON simulation model with SIMULA simulation language. From the result of the throughput-delay performance and the dynamics of buffer state along time for each terminal and ONU, respectively, one can see that the proposed scheme can provide the fairness among not ONUs but terminals. Finally, it is worthwhile to note that the proposed scheme for the public EPON systems might be an attractive solution for providing the fairness among subscriber terminals.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.241-249
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• 2014

The continuous observations for atmospheric aerosol were carried out during 3 years (2009-2011) by using a multi-wavelength Raman lidar at the Gwangju Institute of Science and Technology (GIST), Korea ($35.11^{\circ}N$, $126.54^{\circ}E$). The particle depolarization ratios were retrieved from the observations in order to distinguish the Asian dust layer. The vertical information of Asian dust layers were used as input parameter for the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model for analysis of its backward trajectories. The source regions and transport pathways of the Asian dust layer were identified. The most frequent source region of Asian dust in Korea was Gobi desert during observation period in this study. The statistical analysis on the particle depolarization ratio of Asian dust was conducted according to their transport route in order to retrieve the variation of optical properties of Asian dust during long-range transport. The transport routes were classified into the Asian dust which was transported to observation site directly from the source regions, and the Asian dust which was passed over pollution regions of China. The particle depolarization ratios of Asian dust which were transported via industrial regions of China was ranged 0.07-0.1, whereas, the particle depolarization ratio of Asian dust which was transported directly from the source regions to observation site were comparably higher and ranged 0.11-0.15. It is considered that the pure Asian dust particle from source regions were mixed with pollution particles, which is likely to spherical particle, during transportation so that the values of particle depolarization of Asian dust mixed with pollution was decreased.

• Korean Security Journal
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• no.44
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• pp.7-35
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• 2015

The objective of this article is to inform and document the contemporary development of the private security industry in Queensland Australia, a premier holiday destination that provide entertainment for the larger region. The purpose of this review is to examine the comtemporary development of mandated licensing regimes regulating the industry, and the necessary reform agenda. The overall aim is threefold: first, to chart the main outcomes of the two-wave of reforms since the mid-'90s; second, to examine the effectiveness of changes in modes of regulation; and third, to identify the criteria that can be considered a best practice based on Button(2012) and Prenzler and Sarre's(2014) criteria. The survey of the Queensland regulatory regime has demonstrated that, despite the federal-guided reforms, there remain key areas where further initiatives remain pending, markedly case-by-case utilisation of more proactive strategies such as on-site alcohol/drug testing, psychological evaluations, and checks on close associates; lack of binding training arrangement for technical services providers; and targeted auditing of licensed premises and the vicinity of venues by the Office of Fair Trading, a licensing authority. The study has highlighted the need for more determined responses and active engagements in these priority areas. This study of the development of the licensing regimes in Queensland Australia provides useful insights for other jurisdictions including South Korea on how to better manage licensing system, including the measures required to assure an adequate level of professional competence in the industry. It should be noted that implementing a consistency in delivery mode and assessment in training was the strategic imperative for the Australian authority to intervene in the industry as part of stimulating police-private partnerships. Of particular note, competency elements have conventionally been given a low priority in South Korea, as exemplified through the lack of government-sponsored certificate; this is an area South Korean policymakers must assume an active role in implementing accredited scheme, via consulting transnational templates, including Australian qualifications framework.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1119-1126
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• 1998

Background: In this study, we investigated the early time course of expression of the major histocompatibility(MHC) antigens, intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1(VCAM-1), interleukin-6 and the histopathological changes in the coronary arteries of cardiac allografts exchanged between inbred mice strains that differ in one loci of class I major histocompatibility antigen (B10.BR to B10.A). Material and Method: No immunosuppressive therapy was used. Both allografts and the hearts of the recipients were harvested at 7(group 1, n=6), 15(group 2, n=6), 21(group 3, n=6), and 30(group 4, n=6) days after transplantation. They were examined by immunohistochemistry, microscopy and morphometry. All allografts had contractions at the time of harvest. Result: A strong MHC class I antigen expression was present on the endothelial and medial cells of the coronary arteries in group 1 and remained unchanged in the rest of the groups. However, MHC class II reactivity was none or very little at any time. Mild to moderate ICAM-1 expression was observed on the endothelial cells, but not on the medial cells at any time by 30 days. VCAM-1 expression was strong both on the endothelial and medial cells at any time. Moderate degree expression of interleukin-6 was observed from 7 to 30 day specimens. Histopathologically, percentage of affected vessels(vessels with intimal thickening) was less than 10 % in 7 day group and increased up to 50 % at 30 days. Mean percent narrowing of the lumen of the affected vessels revealed less than 20 % at 7 days and 40 % at 30 days. The area occupied by tropomyosin positive cells in the intimal lesion, graded from 0 to 3, showed gradual increase but remained between grade 0 to 1 by 30 days. Medial integrity was also well preserved at any time. Moderate perivascular mononuclear cell infiltration was observed at 7 days and it was progressively increased upto 30 days. Recipients' heart revealed no positive immunopathologic findings. Conclusion: In this study, the early time course of progression of the transplantation vasculopathy was demonstrated in the murine heterotopic heart transplant model.

• Journal of Technology Innovation
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• v.24 no.1
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• pp.143-167
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• 2016

The purpose of this study is to analyze changes of innovation activities and their performance in pre-IPO and post-IPO of KOSDAQ IPO listed companies in medical and pharmaceutical fields, which require high R&D investment, from 2000 to 2005 in Korea. The innovation efficiencies of the IPO companies were measured before and after three years based on the DEA model. The financial data and patent information of the listed company during total 6 years, which were 3 years before IPO and 3 years after IPO, were collected. The main results of this research are as follows. First, it took an average 12.86 years until IPO in the start-up of the IPO companies in the pharmaceutical sector, and innovation was on average more active than the IPO before. R&D investment was higher than the IPO before, and the number of the applied patent during 3 years after IPO was 16.67 which was increased from 8.43 during 3 years before IPO. In addition, the average scope of technology of the IPO companies was expanded from 11 to 22 technology fields during previous 3 year and after 3 year each, and financial growth after IPO was lower than the previous IPO. Second, the financial performance of R&D investment and the performance of patent activity were weakened in the efficiency after the IPO, and the integrated performance from the patenting activities and the R&D investment was decreased after the IPO. Finally, the efficiency of the financial performance of the patenting activity was lower than the efficiency of the financial performance of the patent and R&D investment and patent activities under the R&D investment. In particular, the inefficiency of the firms' patenting activities performance after the IPO was caused by the decreasing return to scale, according to the results of this study. This results implicate that the expansion of R&D investments through the IPO had not lead to the financial performance of the market, and that the overall inefficiency since the IPO is due to the inefficiencies at the stage for the outcome of innovation activity rather than the output obtained through the R&D investments that appear to lead the performance of the market.

• Journal of Technology Innovation
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• v.22 no.4
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• pp.235-259
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• 2014

New product or new technology developments are directly linked to a firm's survival and thus their performance and improvement are gaining attention in the midst of rapidly changing business environment and aggravating competition. However, despite SMEs' significance in the national economy, they are limited in terms of size and resources in possession, so the government provides a variety of supports as a policy. According to a study on the organizational life cycle, a firm's limits and difficulties differ by growth stage, so the supports need to be tailored. Based on the data from 2,575 firms that responded to the "2011 SMEs Technological Statistics," how technological capability level and deviation in the R&D process affect the R&D sales performance was studied. The result of analysis revealed that the technological capability has a positive impact on the R&D sales performance. It was also learned that the relationship between deviation in the technological capability and R&D sales performance was moderated by the government support. For the hypothesis that the government support would have a different moderating effect by growth stage for the impact the technology level has on the R&D sales performance, the empirical analysis showed a different meaningful moderating effect for each growth stage. The theoretical implications of the study are that, instead of a simple relation of dynamics that does not take the growth stages into account, it suggested a more realistic causal relationship model that reflects the complex environment the SMEs are in and that the need for measuring and using the deviation in technological capability as a research variable has been justified. The practical implications are that the government policy for supports can be tailored to a growth stage and that the guidelines have been suggested to effectively use the government funding by encouraging the SMEs in a different growth stage to adapt to the customized policy.

• Radiation Oncology Journal
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• v.27 no.1
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• pp.35-41
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• 2009

Purpose: This study was designed to determine the optimum radiotherapy technique for internal mammary node (IMN) irradiation after breast-conserving surgery. Materials and Methods: We selected ten cases of early stage partial mastectomy for plan comparison. Five of the patients were treated to the right-side breast and the rest of the patients were treated to the left-side breast. For each case, four different treatment plans were made to irradiate the entire breast, IMNs and supraclavicular lymph nodes (SCLs). The four planning techniques include a standard tangential field (STF), wide tangential field (WTF), partially wide tangential field (PWT) and a photon-electron mixed field (PEM). We prescribed a dose of 50.4 Gy to the SCL field at a 3 cm depth and isocenter of the breast field. Results: The dose distribution showed clear characteristics depending on the technique used. All of the techniques covered the breast tissue well. IMN coverage was also good, except for the STF, which was not intended to cover IMNs. For the cases of the left-side breasts, the volume of the heart that received more than 30 Gy was larger (in order) for the WTF, PWT, PEM and STF. For radiation pneumonitis normal tissue complication probability (NTCP), the PWT showed the best results followed by the STF. Conclusion: Despite the variety of patient body shapes, the PWT technique showed the best results for coverage of IMNs and for reducing the lung and heart dose.

• Journal of Korea Water Resources Association
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• v.53 no.2
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• pp.107-119
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• 2020

This study analyzed past drought characteristics based on the observed rainfall data and performed a long-term outlook for future extreme droughts using Representative Concentration Pathways 8.5 (RCP 8.5) climate change scenarios. Standardized Precipitation Index (SPI) used duration of 1, 3, 6, 9 and 12 months, a meteorological drought index, was applied for quantitative drought analysis. A single long-term time series was constructed by combining daily rainfall observation data and RCP scenario. The constructed data was used as SPI input factors for each different duration. For the analysis of meteorological drought observed relatively long-term since 1954 in Korea, 12 rainfall stations were selected and applied 10 general circulation models (GCM) at the same point. In order to analyze drought characteristics according to climate change, trend analysis and clustering were performed. For non-stationary frequency analysis using sampling technique, we adopted the technique DEMC that combines Bayesian-based differential evolution ("DE") and Markov chain Monte Carlo ("MCMC"). A non-stationary drought frequency analysis was used to derive Severity-Duration-Frequency (SDF) curves for the 12 locations. A quantitative outlook for future droughts was carried out by deriving SDF curves with long-term hydrologic data assuming non-stationarity, and by quantitatively identifying potential drought risks. As a result of performing cluster analysis to identify the spatial characteristics, it was analyzed that there is a high risk of drought in the future in Jeonju, Gwangju, Yeosun, Mokpo, and Chupyeongryeong except Jeju corresponding to Zone 1-2, 2, and 3-2. They could be efficiently utilized in future drought management policies.