• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.743-776
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• 2012

This study utilizes the meta-analysis for the benefits transfer (MA-BT) approach to measure social costs the 7 target sites in the City and County of Honolulu. The estimated MA models (MA-1 and MA-1) were evaluated in terms of validity and reliability criteria. This study utilized a parametric t-test and a non-parametric sign rank test for checking validity. A transfer error measured by an absolute percentage difference was utilized to check reliability their similarity. The GIS was utilized for data collection in order to measure social costs for each target site. The results clearly demonstrated that social costs were substantially higher thant direct costs and varied market conditions and different methods used. In terms of validity and reliability criteria, MA models were preferred to the mean transfer value approach. MA-BT approach is desirable for measuring social costs for a project designed to measure social costs for these 7 proposed landfill sites with inaccessible data, on short time frames, and with little money. If researchers and planners have enough time and money, they can implement primary research. If not, the meta-analysis for the benefits transfer approach can be much better than no framework. The use of a GIS can help to identify secondary data within a specific radius of each target site.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.5
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• pp.445-457
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• 2017

In this study, we developed an approach to better account for uncertainties in estimated contributions from fine particulate matter ($PM_{2.5}$) modeling. Our approach computes a Concentration Correction Factor (CCF) which is a ratio of observed concentrations to baseline model concentrations. We multiply modeled direct contribution estimates with CCF to obtain revised contributions. Overall, the modeling system showed reasonably good performance, correlation coefficient R of 0.82 and normalized mean bias of 2%, although the model underestimated some PM species concentrations. We also noticed that model biases vary seasonally. We compared contribution estimates of major source sectors before and after applying CCFs. We observed that different source sectors showed variable magnitudes of sensitivities to the CCF application. For example, the total primary $PM_{2.5}$ contribution was increased $2.4{\mu}g/m^3$ or 63% after the CCF application. Out of a $2.4{\mu}g/m^3$ increment, line sources and area source made up $1.3{\mu}g/m^3$ and $0.9{\mu}g/m^3$ which is 92% of the total contribution changes. We postulated two major reasons for variations in estimated contributions after the CCF application: (1) monthly variability of unadjusted contributions due to emission source characteristics and (2) physico-chemical differences in environmental conditions that emitted precursors undergo. Since emissions-to-$PM_{2.5}$ concentration conversion rate is an important piece of information to prioritize control strategy, we examined the effects of CCF application on the estimated conversion rates. We found that the application of CCFs can alter the rank of conversion efficiencies of source sectors. Finally, we discussed caveats of our current approach such as no consideration of ion neutralization which warrants further studies.

• Journal of Communications and Networks
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• v.12 no.4
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• pp.289-307
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• 2010

The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper studies non-asymptotic model selection for the general case of arbitrary (random or deterministic) design matrices and arbitrary nonzero entries of the signal. In this regard, it generalizes the notion of incoherence in the existing literature on model selection and introduces two fundamental measures of coherence-termed as the worst-case coherence and the average coherence-among the columns of a design matrix. It utilizes these two measures of coherence to provide an in-depth analysis of a simple, model-order agnostic one-step thresholding (OST) algorithm for model selection and proves that OST is feasible for exact as well as partial model selection as long as the design matrix obeys an easily verifiable property, which is termed as the coherence property. One of the key insights offered by the ensuing analysis in this regard is that OST can successfully carry out model selection even when methods based on convex optimization such as the lasso fail due to the rank deficiency of the submatrices of the design matrix. In addition, the paper establishes that if the design matrix has reasonably small worst-case and average coherence then OST performs near-optimally when either (i) the energy of any nonzero entry of the signal is close to the average signal energy per nonzero entry or (ii) the signal-to-noise ratio in the measurement system is not too high. Finally, two other key contributions of the paper are that (i) it provides bounds on the average coherence of Gaussian matrices and Gabor frames, and (ii) it extends the results on model selection using OST to low-complexity, model-order agnostic recovery of sparse signals with arbitrary nonzero entries. In particular, this part of the analysis in the paper implies that an Alltop Gabor frame together with OST can successfully carry out model selection and recovery of sparse signals irrespective of the phases of the nonzero entries even if the number of nonzero entries scales almost linearly with the number of rows of the Alltop Gabor frame.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.173-182
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• 2019

This study attempts to improve the understanding of the rapidly growing online video platform market such as Youtube and OTT, and to investigate the attributes and relative importance of them. For this purpose, the factors that influence the choice to use were derived through literature studies and the Focus Group Interview (FGI), and the priority of the factors was calculated through the analytic hierarchy process (AHP). The upper layer of the AHP structure was 'Relationship', 'Entertainment', 'Informativity', and 'Convenience', and the lower layer was structured into 13 elements. The importance priority analysis among the factors that influence the choice to use was done by teenagers, 20s, and 30s and the results are summarized as follows : First, Users consider the 'Just for fun' and 'Satisfaction of interests' as the most important factors, followed by 'Easy accessibility to use', 'Vicarious satisfaction', 'Usefulness of Information', and 'Up-to-dateness of information'. Second, the ranking of the upper layer was in the order of 'Entertainment'-'Informativity'-'Convenience'-'Relationship'.As a result of AHP,'Entertainment' was 3.6 times more important than 'Relationship'. In the comparison by age group, only teenagers regarded that 'Convenience' is more important than 'Informativity'. According to the characteristics of the age group, the lower layer of teenagers consider 'Convenient function' to be important and ranked 'Usefulness of information' in 8^th. While 'Vicarious satisfaction' ranked 4th out of 13 factors in the entire age group, those in their 20s and 30s ranked 8^th, showing a difference. In the case of 20s, 'Reasonable price' was ranked 4th and the 'Diversity of Information' was ranked 5th, Otherwise 30s consider 'Trustworthiness of Information' to the third. Third, unlike 'Convenience' which was the lower-rank in the upper layer AHP analysis, 'Easy accessibility to use', the lower-layer of convenience, ranked third overall in the importance analysis among the 13 lower-layer factors, and showed a similar patterns in the age groups results. In the conclusion, this study demonstrates that 'Convenience' and 'Vicarious satisfaction' factors, which were not relatively well addressed in the previous studies, are the key factors to be considered in. By presenting the results of the importance analysis on each of the selected attributes, This study has a practical implication that Industries such as on-line video service platform provider can use the importance priority in establishing the directions of future strategy.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.629-642
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• 2018

Future variability of the spatial patterns of rainfall events is the point of water-related risks and impacts of climate change. Recent related researches are mostly conducted based on the outcomes from General Circulation Models (GCMs), especially Coupled Model Intercomparison Project, phase 5 (CMIP5) GCMs which are the most advanced version of climate modeling system. GCM data have been widely used for various studies as the data utility keep getting improved. Meanwhile the model performances especially for raw GCM outputs are rarely evaluated prior to the applications although the process would essential for reasonable use of model forecasts. This study attempt to quantitatively evaluate the skills of 29 CMIP5 GCMs in reproducing spatial climatologies of precipitation in East Asia. We used 3 different gridded observational data as the references available over the study area and calculated correlation and errors of spatial patterns simulated by GCMs. As a result, the study presented diversity of the GCM evaluation in the performance, rank, or accuracy by different configurations, such as target area, evaluation method, and observation data. Yet, we found that Hadley-centre affiliated models comparatively performs better for the meso-scale area in East Asia and MPI_ESM_MR and CMCC family showed better performance specifically for the korean peninsula. We expect that the results and thoughts of this study would be considered in screening suitable GCMs for specific area, and finally contribute to extensive utilization of the results from climate change related researches.

• Journal of Korean Academy of Nursing Administration
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• v.4 no.1
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• pp.5-17
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• 1998

The Purpose of this study is to find out differences among the leader's traits on the hierarchy of Nurse managers in Nurse system of the hospital. In this study 152 managers over head nurse working in 6 University hospitals and 5 general hospitals were selected and the questionary paper answered by them was collected from 1st to 30th in September in 1997. The measuring instrument used in this study is the one integrated and classified by Stogdill (1981), which nurse professor and 2 students of the master's course translated and modified with myself. And its validity was verified through making a test on 130 nurses. The measuring instrument used in this study is made up of 4 items about physical characteristics, 3 items about social background, 4 items about intelligence and ability, 17 items about personaity, 6 items about task-related characteristics, 9 items about social characteristics and 8 items about general background in the triats of leader. And this instrument is made to be marked using five point Likert type. It's reliability is Cronbach's Alpha =.93. The data for study were analyzed through SPSS/PC+ The result of this study are as follows: 1. The order in importantly perceptible degree of the leader's traits showed like these: the intelligence and ability (M=4.683), the task-related characteristics (M=4.605), the personality (M=4.39), the social characteristics (M=4.327), the social back-ground (M=4.056), the physical characteristics (M=3.601). 2. The order in degree to percept the importance of 44 detailed items of the leader's traits showed like these: the judgement and decisiveness (M=4.967), the sense of responsibility (M=4.904), the activity and energy (M=4.796), the self-confidence (M=4.776), the creativity (M=4.748), the intelligence (M=4.743), the responsibility in the pursuit of objectives (M=4.743), the enthusiasm (M=4.717), the objectivity (M=4.704), the moral sense and ethical conduct (M=4.704), the ability to enlist cooperation (M=4.694), the strength of conviction (M =4.678), the enterprise (M=4.691), the administrative ability (M=4.678) and the cooperativeness (M=4.638) 3. As the result of analyzing the leader's trait differences on the hierarchy of nurse managers in six factors of the leader's traits, the social background showed the meaningful differences(F=4.983, P=0.008). 4. As the result of analyzing the leader's traits defferences made from the upper first to 15th rank among the detailed items of the leader's trait factors on the heirarchy of nurse managers, the meaningful defferences appeared in the following items: the objectivity(F=3.413, P=0.033), the creativity (F=3.550, P=0.031), the sense of responsibility(F=3.345, P=0.049), and the administrative ability (F=3.363, P=0.037). 5. As the result of analyzing the leader's trait factors in general background, only the social background of 6 leader's trait factors showed the meaningful differences according to the working place (F=4.057, P=0.008). The study shows that we should consider the above leader's trait factors in selecting nurse managers and that we should develop the educational program for hierarchy of nurse managers urgently.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.832-845
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• 1998

The purpose of this study was to compare the marginal fit of all ceramic crowns prepared from alumina slip casting, which is consistent with the conventional In-ceram system, and those fabricated from alumina tapes which is currently under development in an effort to alleviate complexities involved in the forming procedure of the In-ceram crown core. All ceramic crowns, made of In-ceram(slip casting) and alumina tapes(Doctor blade casting), were prepared with $90^{\circ}\;and\;135^{\circ}$ shoulder margins. The crowns were cemented with a glass ionomer cement and embeded in epoxy resin. The embedded crowns were sectioned faciolingually and mesiodistally and marginal discrepancies and marginal gaps were measured under the Measurescope MM II. The measurements were analyzed using Wilcoxon rank sum test and Kruskal-Wallis test and the results were as follows: 1. In the case of $90^{\circ}$ shoulder margin, the combined marginal discrepancies and marginal gaps were $78.3{\mu}m\;and\;44.4{\mu}m$ respectively, for the all ceramic crowns fabricated using the alumina tapes. In comparison, the values were $65{\mu}m\;and\;25.5{\mu}m$ for the In-ceram crowns. For the marginal gaps a statistical difference existed (p<0.05) but no significant difference was observed for the marginal discrepancy (p>0.05). 2. In the case of $135^{\circ}$ shoulder margin, the combined marginal discrepancy and marginal gaps were $82.1{\mu}m\;and\;40.2{\mu}m$ respectively, for the all ceramic crowns formed with the tapes. As compared with the marginal discrepancy and gaps of the $90^{\circ}$ shoulder margin in the fabricated from the alumina tapes, no significant statistical differencies were discerned in both cases (p>0.05). 3. There was no statistically significant difference in the fits among four locations around the margins of the all ceramic crowns fabricated using the alumina tapes. The results obtained in this study showed that the marginal fits of the glass infiltrated alumina cores fabricated from the alumina tapes are slightly higher value than those prepared using the In-ceram but the difference is within a clinically acceptable range.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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• pp.280-293
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• 2004

Statement of problem. Glass fiber post is one of recent developments to accommodate esthetic restoration for endodontically treated teeth. This has many advantages over conventional post system in physical properties, esthetic factor, risk of root and restoration fracture, adhesion to core, radiopacity, removal and retrievabilty, biocompatibility and chemical stability. Purpose. This in vitro study was to evaluate the most suitable type of resin core for the glass fiber post through surveying the fracture modes and the maximum load that fractures the tooth. Material and methods. 50 sound maxillary premolars restored with glass fiber posts($ParaPost^{(R)}$ Fiber White) and different types of resin cores(ParaCore, $Z100^{TM}$, $Rebilda^{(R)}$ and $Admira^{(R)}$) were prepared and loaded to faiure in a universal test machine. The maximum fracture load and fracture mode were investigated in the specimens that were restored with resin and those of metal cast and core. With the data, Wilcoxon rank sum test was used to validate the significance between the test groups, and Tukey' s studentized range test was used to check if there is any significant statistical difference between each test group. Every analysis was approved with 95% reliance. Results. On measuring the maximum fracture load of teeth specimens, there was a significant difference between the maximum fracture loads of the tooth specimens. ParaCore showed the highest mean maximum fracture load followed by $Z100^{TM}$. And, the distribution of fracture mode of tooth specimens showed generally Type D, the three parted fracture of the core around the post was mostly seen(62.5%), and specifically, ParaCore showed 90% and $Z100^{TM}$ showed 100% Type D fracture. Conclusion. Referring to the values of maximum fracture load and mean compressive fracture load, ParaCore and $Z100^{TM}$ had high values and are recommended as tooth colored resin core material for glass fiber post. CLINICAL IMPLICATIONS. This study was carried out intending to be of aid in selecting the appropriate resin core for the glass fiber post. The dual cure type composite resin ParaCore and light cure type composite resin $Z100^{TM}$ have good properties and are recommended as tooth colored resin core material for glass fiber post.

• Journal of Gastric Cancer
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• v.4 no.1
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• pp.32-35
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• 2004

Purpose: The most important prognostic factors in gastric cancer is the depth of invasion of the primary tumor and lymph node metastasis. The nodal staging of the 5th edition of the Union Internationale Contrala Cancrums (UICC) TNM classification in 1997 was changed based on the number of metastatic lymph node. We attempted to evaluate the prognostic significance of N2 group metastasis in pT3pN1 gastric cancer patients by comparing two different nodal staging systems. Materials and Methods: A retrospective analysis was made for 352 gastric cancer patients who underwent curative resection, including D2 dissection, from 1991 to 1997 at Asan Medical Center. A clinicopathologic comparison between two groups by using a nodal staging systems was summarized into a table. Cumulative survival rates were calculated by using the Kaplan-Meier method. The difference between the two groups was evaluated by using the log rank test with SPSS 11.5 for Windows Results: There were no statistical differences in clinicopathologic factors. However, there was a significant difference in survival rate between the two groups (P=0.0009). This suggests that N2 group metastasis in pT3pN1 gastric cancer patients has a clinical significance for predicting prognosis. Conclusion: Our results suggest a possibility of prognostic significance of N2 group metastasis. Therefore, anatomical location of the lymph node should be described.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.661-675
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• 2009

The carelessly and illegally copied contents are raising serious social problem as internet and multimedia technologies are advancing. Therefore, development of video copy detection system must be settled without delay. In this paper, we propose the hierarchical video copy detection method that estimates similarity using statistical characteristics between original video and manipulated(transformed) copy video. We rank according to luminance value of video to be robust to spacial transformation, and choose similar videos categorized as candidate segments in huge amount of database to reduce processing time and complexity. The copy videos generally insert black area in the edge of the image, so we remove rig black area and decide copy or not by using statistical characteristics of original video and copied video with center part of frame that contains important information of video. Experiment results show that the proposed method has similar keyframe accuracy to reference method, but we use less memory to save feature information than reference's, because the number of keyframes is less 61% than that of reference's. Also, the proposed method detects if the video is copied or not efficiently despite expansive spatial transformations such as blurring, contrast change, zoom in, zoom out, aspect ratio change, and caption insertion.