• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.105-114
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• 2019

Recently, the paradigm of road policy has been focused on user safety. Recently, the number of road facility improvement project has been continuously increased but the economic feasibility (B/C ratio) is insufficient. Therefore, it is necessary to select a reasonable road improvement project through accurate and objective analysis of the road safety evaluation. In this study, to develop a new road safety evaluation method, data were collected based on the current road safety evaluation method for 75 routes including national roads and provincial ones. Based on the collected data, problems were analyzed and utilized as the basic factors of the new road safety evaluation method. Therefore, in this study, traffic accidents were reflected as a general evaluation item by weighing to solve these problems, and the evaluation items were added from experiences and ideas of the local public officials. For each evaluation item, a reasonable weight was determined through AHP (Analytic Hierarchy Process) questionnaire evaluation with highway experts. In addition, the safety index was determined based on the evaluation criteria for each evaluation item. The criteria for evaluating the danger zone are determined by the overall safety index. Finally, the criteria for selection of road improvement projects based on the overall risk level were derived.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.451-461
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• 2018

This study investigated changes in the youth smoking rate and smoking cessation rates before and after a cigarette price increase in 2015. Specifically, the changes in smoking rate, smoking cessation attempt rate, selection rate and amount of smoking were investigated using primary data pertaining to Korean Youth Risk Behavior obtained from a web-based survey of youth general characteristics, mental health, subjective grade, drinking and smoking related characteristics before and after a cigarette price increase. To accomplish this, 800 middle school and high school students in 9th (2013), 10th (2014), 11th (2015) were surveyed. The current youth smoking rate was slightly decreased from 9.7% in 2013 to 9.2% in 2014, while the smoking rate in 2015 decreased significantly by 15.2% after the cigarette price increased to 7.8%. These results confirmed that increasing cigarette price is very effective at decreasing youth smoking rate, providing motivation to stop smoking and preventing smoking. The prevention of smoking and inducement to stop smoking during adolescence is very important because the majority of teenage smokers continue smoking into their adulthood. In addition to expanding a completely non-smoking area and a comprehensive ban on tobacco advertising, promotion and sponsorship should be urgently sought, and the effect can be maximized when the WHO FCTC faithfully implements the already-founded treaty.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.15-24
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• 2020

With the development of the chemical industry, the chemical accident is increasing every year, thereby increasing the risk of accidents caused by chemicals. The Ministry of Environment provides the criteria for determining shelter-in-place or outdoor evacuation by material, duration of accident, and distance from the toxic substance leak. However, it is hard to say that the criteria for determining the transition point are not clear. Transition point mean the time that evacuation method is switched from shelter-in-place to outdoor evacuation. So, the purpose of this study was to calculate appropriate transition point by comparing the cumulative toxic load. Namdong-gu in Incheon Metropolitan City was finally selected as the target area, considering the current status of the population of Incheon Metropolitan City in 2016 and the statistical survey of chemicals in 2016. The target materials were HCl, HF, and NH₃. Modeling was simulated by ALOHA and performed assuming that the entire amount would be leaked for 10 min. Residents' evacuation scenarios were assumed to be shelter-in-place, immediate outdoor evacuation, and outdoor evacuation at an appropriate time after shelter-in-place. Based on the above method, the appropriate transition point from residents located in A(800 m away), B(1,200 m away), C(1,400 m away) and D(2,200 m away) was identified. In HCl, appropriate transition point was after 15 min, after 16 min, after 17 min, after 20 min in order by A, B, C and D. In HF, appropriate transition point was before 1 min or after 16 min, before 4 min or after 19 min, before 5 min or after 20 min, before 14 min or after 26 min in order by A, B, C and D. In NH₃, appropriate transition point at A was before 4 min or after 16. Others are not in chemical cloud. This study confirmed the transition point to minimize the cumulative toxic load can be obtained by quantitative method. Through this, it might be possible to select evacuation method quantitatively that cumulative toxic load are minimal. In addition, if the shelter-in-place is maintained without transition to outdoor evacuation, the cumulative toxic load will increase more than outdoor evacuation. Therefore, it was confirmed that actions to reduce the concentration of chemicals in the room were necessary, such as conducting ventilation after the chemical cloud passed through the site.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.140-155
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• 2020

This study was conducted to identify the location characteristics of infected farms in the areas where livestock diseases were clustered(southern Gyeonggi-do and Chungcheong-do), analyze the probability of disease occurrence in poultry farms, find out the areas corresponding to the conditions, and use them as the basis for prevention of livestock diseases, selection of discriminatory prevention zones, and establishment of prevention strategies and as the basic data for complementary measures. The increase of one poultry farm within a radius of 3-kilometers increases the risk of HPAI infection by 10.9% compared to the previous situation. The increase of 1m in distance from major roads with two lanes or more reduces the probability of HPAI infection by 0.001% compared to the previous situation. If the distance of the poultry farm located with 15 kilometers from a major migratory bird habitat increases by 15 to 30 kilometers, the chance of infection with HPAI is reduced by 46.0%. And if the distance of the same poultry farm increase by more than 30 kilometers, the chances of HPAI infection are reduced by 88.5%. Based on the results of logistic regression, the predicted probability was generated and the actual area of the location condition with 'more than 15 poultry farms within 3km a radius of, within 1km distance from major roads, and within 30km distance from major migratory birds habitat was determined and the infection rate was measured. It is expected that the results of this study will be used as basic data for preparing the data and supplementary measures when the quarantine authorities establish discriminatory quarantine areas and prevention strategies, such as preventive measures for the target areas and farms, or control of vehicles, by identifying the areas where livestock diseases are likely to occur in the region.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.243-249
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• 2020

This study analyzes the earnings management that can occur in the process of public offering in the process of SMEs reducing cost of capital, risks and seeking opportunities for direct financing. Since a company is subject to strict supervision during the IPO process, it is possible to prevent the phenomenon that the company value evaluated in the market is underestimated, or to perform earnings management in consideration of overestimation. This study attempted to verify the degree of earnings management through discretionary accruals and actual earnings management values that can affect the earnings ratio of the IPO of a company. For this study, total accruals were calculated and analyzed through discretionary accruals, sales, costs, and actual earnings management adjustments from production activities. As a result of the analysis, discretionary accruals, which are the countermeasures for earnings management during the listing process, have a positive(+) relationship in both the stock price return and the sales adjustment value, which can be viewed as a factor that induces high valuation. As a result of this, there may be a risk of adverse selection for the benefit amount, and information asymmetry may exist for public offering stocks. This study can provide useful guidelines for evaluating corporate value to domestic SMEs and investors that do business with Chinese companies as well as China through the current and type of earnings management of Chinese listed companies.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.71-84
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• 2022

The objective of this study is to develop a two-dimensional (2D) flood model that can perform accurate flood analysis with simple input data. The 2D flood inundation models currently used to create flood forecast maps require complex input data and grid generation tools. This sometimes requires a lot of time and effort for flood modeling, and there may be difficulties in constructing input data depending on the situation. In order to compensate for these shortcomings, in this study, a grid-based model that can derive accurate and rapid flood analysis by reflecting correct topography as simple input data was developed. The calculation efficiency was improved by extending the existing 2×2 sub-grid model to a 5×5. In order to examine the accuracy and applicability of the model, it was applied to the Gamcheon Basin where both urban and river flooding occurred due to Typhoon Rusa. For efficient flood analysis according to user's selection, flood wave propagation patterns, accuracy and execution time according to grid size and number of sub-grids were investigated. The developed model is expected to be highly useful for flood disaster mapping as it can present the results of flooding analysis for various situations, from the flood inundation map showing accurate flooding to the flood risk map showing only approximate flooding.

• Journal of Korean Foot and Ankle Society
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• v.26 no.2
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• pp.95-102
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• 2022

Purpose: This study was based on the Korean Foot and Ankle Society (KFAS) member survey and aimed to report the current trends in the management of syndesmotic injuries over the last few decades. Materials and Methods: A web-based questionnaire containing 36 questions was sent to all KFAS members in September 2021. The questions were mainly related to the preferred techniques and clinical experiences in the treatment of patients with syndesmotic injuries. Answers with a prevalence ≥50% of respondents were considered a tendency. Results: Seventy-six (13.8%) of the 550 members responded to the survey. The results showed that the most preferred method to diagnose a syndesmotic injury was magnetic resonance imaging (MRI). Intraoperatively, the external rotation stress test and the Cotton test were most frequently used to confirm syndesmotic diastasis. The reduction was usually done by a reduction clamp. One 3.5-mm screw was used most frequently over three cortices at 2~4 cm above the ankle joint. The preferred ankle position during fixation was 0° dorsiflexion. Removal of the syndesmotic screw was routinely done by most surgeons, mainly because of the limitation of movement and risk of screw breakage. Factors that affect suture button selection included non-rigid fixation which enables adequate fixation, early weight-bearing, and an infrequent need to remove the hardware. Inadequate reduction was considered the main factor that affects poor prognosis. Conclusion: This study proposes updated information about the current trends in the management of syndesmotic injuries in Korea. Consensuses in both the diagnostic and therapeutic approach to patients with syndesmotic injury were identified in this survey study. This study may raise the awareness of the various possible approaches toward the injury and should be used to further establish a standard protocol for the management of syndesmotic injuries.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.539-548
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• 2022

Objective : Although full-endoscopic lumbar interbody fusion (Endo-LIF) has been tried as the latest alternative technique to minimally invasive transforaminal lumbar interobody fusion (MIS-TLIF) since mid-2010, the evidence is still lacking. We compared the clinical outcome and safety of Endo-LIF to MIS-TLIF for lumbar degenerative disease. Methods : We systematically searched electronic databases, including PubMed, EMBASE, and Cochrane Library to find literature comparing Endo-LIF to MIS-TLIF. The results retrieved were last updated on December 11, 2020. The perioperative outcome included the operation time, blood loss, complication, and hospital stay. The clinical outcomes included Visual analog scale (VAS) of low back pain and leg pain and Oswestry disability index (ODI), and the radiological outcome included pseudoarthosis rate with 12-month minimum follow-up. Results : Four retrospective observational studies and one prospective observational study comprising 423 patients (183 Endo-LIF and 241 MIS-TLIF) were included, and the pooled data analysis revealed low heterogeneity between studies in our review. Baseline characteristics including age and sex were not different between the two groups. Operation time was significantly longer in Endo-LIF (mean difference [MD], 23.220 minutes; 95% confidence interval [CI], 10.669-35.771; p=0.001). However, Endo-LIF resulted in less perioperative blood loss (MD, -144.710 mL; 95% CI, 247.941-41.478; p=0.023). Although VAS back pain at final (MD, -0.120; p=0.586), leg pain within 2 weeks (MD, 0.005; p=0.293), VAS leg pain at final (MD, 0.099; p=0.099), ODI at final (MD, 0.141; p=0.093) were not different, VAS back pain within 2 weeks was more favorable in the Endo-LIF (MD, -1.538; 95% CI, -2.044 to -1.032; p<0.001). On the other hand, no statistically significant group difference in complication rate (relative risk [RR], 0.709; p=0.774), hospital stay (MD, -2.399; p=0.151), and pseudoarthrosis rate (RR, 1.284; p=0.736) were found. Conclusion : Relative to MIS-TLIF, immediate outcomes were favorable in Endo-LIF in terms of blood loss and immediate VAS back pain, although complication rate, mid-term clinical outcomes, and fusion rate were not different. However, the challenges for Endo-LIF include longer operation time which means a difficult learning curve and limited surgical indication which means patient selection bias. Larger-scale, well-designed study with long-term follow-up and randomized controlled trials are needed to confirm and update the results of this systematic review.

• Journal of Chest Surgery
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• v.55 no.1
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• pp.10-19
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• 2022

Background: According to the eighth TNM (tumor-node-metastasis) staging system, the presence of separate tumor nodules in the same lobe is designated as a T3 descriptor. However, it remains unclear whether adjuvant chemotherapy confers survival advantages in this setting. Methods: We retrospectively identified 142 pathologic T3N0M0 patients with additional pulmonary nodules in the same lobe from a single-institutional database from 2004 to 2019. The main outcomes were overall survival and recurrence-free survival. Multivariable Cox regression was used to identify the benefit of adjuvant chemotherapy while adjusting for other variables. Results: Sixty-one patients received adjuvant chemotherapy (adjuvant group) and 81 patients did not receive adjuvant therapy after surgery (surgery-only group). There were no demonstrable differences between the 2 groups regarding hospital mortality and postoperative complications, indicating that treatment selection had not significantly occurred. However, the use of adjuvant chemotherapy was associated with improved 5-year overall survival (70% vs. 59%, p=0.006) and disease-free survival (60% vs. 46%, p=0.040). A multivariable Cox model demonstrated that adjuvant chemotherapy was associated with a survival advantage (adjusted hazard ratio, 0.54; p<0.001). In exploratory analyses of subgroups, the effect of adjuvant chemotherapy seemed to be insufficient in those with small main tumors (<4 cm). Conclusion: Adjuvant chemotherapy was associated with better survival in T3 cancers with an additional tumor nodule in the same lobe. However, the role of adjuvant chemotherapy in patient subgroups with small tumors or those without risk factors should be determined via large studies.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.44-51
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• 2023

Selecting appropriate bidding system in construction projects considering the characteristic of project can be a make-or-break element, so the understanding for bidding system of public construction projects is ever more important from the perspective of both the owner and the contractor. The design-build bidding is commonly referred to as turnkey in Korea, and is a bidding method that is often applied to large public construction projects because it allows new technologies to be applied to the design and facilitates risk management for the owner. In this bidding method, there are only two factors (design score and price score) that affect the selection of the winning bidder, so it is important to understand the influence of each factor, but there is little research on the subject. This study aims to provide a basis for establishing bidding strategies for understanding the influence between design score and price score by analyzing various design-build bidding data of public construction projects. The results of the study show that design score is the factor that has more influence on the ranking of bidders in all three weighted evaluation methods: design-emphasized, price-emphasized, and equalized evaluation. In addition, we found that the correlation between design and price scores was not significant due to the unique bid evaluation structure in Korea.