• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.1
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• pp.29-36
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• 2021

In spite of the highest energy potential among all domestic organic solid wastes. the research on biogas production from cattle manure is limited. In particular, effects of organic content degradation and sawdust addition during storage on biomethane potential have never been investigated. In the present work, we investigated the change of organic content during storage of cattle manure under different temperatures (20℃ and 30℃), and its impact on biomethane potential and odor emissions. 90 days of investigation results showed that 10% of organics in terms of VS and COD were degraded at 20℃ during storage, while 30% were degraded at 30℃. This result impacted on biomethane potential, while 10-13% and 24% reduction were observed from beef and dairy cattle manure, respectively. The temperature also affected on CH4 and odor emissions during storage by 3.3-3.8 times and 29 times. The effect of sawdust on lowering down biomethane potential was found to be substantial, reducing 61-75% compared to the control.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.33-40
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• 2021

In recent years, many construction projects become large and complicated, and construction accidents also steadily increase, which grows interest in the safety and maintenance during construction. Many of the construction accidents are related to temporary construction and structures, but the safety evaluation and management during construction are unclear and indefinite due to the short operating period and continuous change in the formation of the temporary structure. The system support, which is one of the temporary structures to support the pouring load of concrete, was proposed to easily install and dismantle members with connection parts pre-manufactured. The use of the system support is increasing to improve the safety of the temporary structure during construction. However, the system support, which consists of multiple members, still has uncertainties in connectivity between members and supports of vertical members. Therefore, this study analyzed the structure, load, and accident cases of the system support to define the damage scenarios for member connection, support condition, and lateral displacement. The decrease rate of the critical load was analyzed according to the damage scenarios based on the defined unit structure of the system support. In addition, this study provided vulnerable members for each damage scenario, which could induce instability of the temporary structures during design, construction, and operation of the structure.

• Journal of Environmental Impact Assessment
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• v.30 no.4
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• pp.258-269
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• 2021

The purpose of this study is to establish a system to evaluate the ecological soundness of the Geum river basin. The study target area is 14 sub-watersheds of the Geum river basin. For the selection of indicators to ensure transparency and consistency of the evaluation indicators, the ecological soundness indicators were secured by using the indicator adjustment method derived in consideration of the intrinsic weight change characteristics between indicators. The index with the greatest impact on the final composite index was identified as the index of the aquatic ecology among the water quantity, water quality, aquatic ecology, and habitat-riparian environment dimensions. As a result of analyzing the ecological health index of the river, the watershed upstream of the dam (based on the Daecheong -dam) was evaluated to be in relatively good condition until 2014 compared to the base year(2008), and the watershed downstream of the dam was evaluated to be in a poor condition. The annual trend of changes in the ecological soundness index on an annual basis is as follows. In the case of Yongdamdam, Yongdamdamdownstream, Bocheong-chun, Daechungdam, Daechungdamdownstream, and Nonsancheon, although there are differences by time period, the soundness index is in declining. On the other hand, Mujunamdaecheon, Yeongdongcheon, and Gapcheon were evaluated to have improved soundness, while Chogang, Daechungdamupstream, Mihocheon, Gongjugeumgang, and Geumgangestuary were evaluated to deteriorate again after soundness was improved.

• Quality Improvement in Health Care
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• v.27 no.2
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• pp.73-82
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• 2021

Purpose: This study aims to examine the quality of tuberculosis (TB) care after the 1st to 3rd national quality assessment (QA) program for TB healthcare service in Korea was conducted. Methods: We analyzed Health Insurance Review & Assessment Service (HIRA) claims data of new TB patients during the period of January to June from 2018-2020. The new TB patients were defined as TB patients reported to Korea Centers for Disease Control and Prevention Agency (KCDA). The unit of analysis was the patient. Chi-square tests were used to analyze the differences in indicator value according to the types of medical facilities. The QA indicators of TB care were divided into 3 areas consisting of the following 7 quality indicators: 4 indicators of diagnosis test (the rate of acid-fast bacilli smear, the rate of acid-fast bacilli culture, the rate of Mycobacterium tuberculosis-polymerase chain reaction, drug susceptibility test), 1 compliance of treatment guideline, and 2 indicators of care management of TB patients (encounter rate, day of therapy). Results: The QA program for TB care was conducted among 8,246 patients from 534 facilities in 2020. The value of the 7 quality indicators was shown to increase as a result of the QA program. The indicators of the diagnostic test were all higher than 95%, with the exception of the drug susceptibility test which was 84.8%. Both indicators for care management of TB patients were 88.5%. Conclusion: The quality of TB care has been improving with the implementation of the QA program. In order to continue to improve the quality of TB care, it will be necessary to disclose the results of the QA program in medical facilities in the future.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.10-18
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• 2022

Purpose: For smooth performance of flood analysis due to heavy rain disasters at energy storage facilities in the Incheon area, field surveys, observational surveys, and pre-established reports and drawings were analyzed. Through the field survey, the characteristics of pipelines and rivers that have not been identified so far were investigated, and based on this, the input data of the SWMM model selected for inundation analysis was constructed. Method: In order to determine the critical duration through the probability flood analysis according to the calculation of the probability rainfall intensity by recurrence period and duration, it is necessary to calculate the probability rainfall intensity for an arbitrary duration by frequency, so the research results of the Ministry of Land, Transport and Maritime Affairs were utilized. Result: Based on this, the probability of rainfall by frequency and duration was extracted, the critical duration was determined through flood analysis, and the rainfall amount suggested in the disaster prevention performance target was applied to enable site safety review. Conclusion: The critical duration of the base was found to be a relatively short duration of 30 minutes due to the very gentle slope of the watershed. In general, if the critical duration is less than 30 minutes, even if flooding occurs, the scale of inundation is not large.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.1
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• pp.1-12
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• 2022

Tilia amurensis is an important honey plant. As T. amurensis mainly distributes mountainous area with various elevations in Korea, accurate prediction of blooming time at the different elevation would benefit forest beekeepers. In this study, we measured time-dependent blooming progress of T. amurensis in Mt. Gariwang area ranging from 500-1500m. Additionally we collected blooming data from web and published literatures and estimated the variation of blooming time relative to the geographic locations. Flowers began to bloom from July 6 to July 22 with full blooming on July 14 in location where elevation is 638m in Mt. G ariwang area in 2021. Based on these databases, a growing degree day (G DD) model was developed for prediction of T. amurensis blooming progress using average daily temperatures. Using the starting date of G DD accumulation of January 1 and base temperature of 5 ℃, blooming period ranging from 10% to 90% of cumulative blooming rate was estimated as 860-1198 degree days (DD). This corresponded to the beginning to the end of July in Mt. Gariwaning area in 2021. This model could explain the phenological variations of T. amurensis flower blooming possibly affected by elevation within geographic area, latitude or year relative to the climate change, and aid forest beekeepers for better timing of nectar foraging by honey bees.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.187-193
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• 2022

In the Yeongdong region of Gangwon-do, coastal areas are important resources in terms of cultural, social and economic aspects. However, the coast of Gangwon-do is experiencing severe erosion, and it is concerned that its adverse effects will gradually increase. In this study, coastline changes of Yangyang and Gangneung in Gangwon-do were tracked and analyzed over a long period of time. In order to build time series image data, aerial photos from the 1940s to the present were mainly used, and data from CORONA satellite, which operated from the 1960s to the early 1970s, were collected and used together. Using 51cm resolution ortho image and 2m resolution Digital Elevation Model(DEM) as reference, ground control points were selected to perform geometric correction on the aerial photos and CORONA images. Subsequently, Canny edge detector applied to these images to extract the coastlines. As a result of analyzing the extracted and vectorized coastlines by overlaying them in chronological order, erosion and deposition occurring around the artificial structures and on the nearby beaches were observed. In this study, the effect of seasonal variation, tide, and various coastal management including the beach filling were not considered. Because coastal erosion is greatly affected by geographic factors, each local government must find its own solution. Continuous research and local data accumulation are required.

• Journal of Environmental Impact Assessment
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• v.31 no.3
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• pp.129-140
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• 2022

Environmental impact assessment on development projects is a process in which various stakeholders derive consultations by reflecting project characteristics and regional environmental status, and implementation of consultations is a prerequisite for securing sustainability of the local environment. The business plan can be changed to respond to changes in social and environmental conditions. And the business plan for which the environmental impact assessment consultation has been completed, it can be changed as a systematically prepared procedure (called Consultations on Amendment). As a result of investigating and analyzing the current status and major changes in the development project, Consultations on Amendment in industrial complexes were the most common, and the environmental impact is increasing accordingly. As the results of the analysis of operational status and the case studies, the main causes of Consultations on Amendment in industrial complex can be summarized into three categories: (1) formal demand forecasting for tenant industries, (2) excessive omission and simplification of administrative procedures under the Special Act, and (3) the use of an expedient change consultation system to facilitate environmental impact assessment consultation and shorten the period. This study proposes the following three measures to prevent the deterioration of the environmental impact assessment function due to frequent consultations on industrial complex changes; (1) Ensuring residents' participation procedures for Consultations on Amendment that changes important matters, (2) Reasonable revision of the "Simplification of Industrial Complex Procedures Act" to enhance the feasibility of industrial complex development plans and locations, (3) Development of evaluation criteria and methods for verification of real demand for objective demand management for industrial complexes, and (4) Preparation of a review guideline for Consultations on Amendment.

• Economic and Environmental Geology
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• v.55 no.3
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• pp.219-229
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• 2022

Bentonite is being considered as a candidate for buffer material in geological disposal systems for high-level radioactive wastes. In this study, the effect of cement-bentonite interactions on bentonite alteration was investigated by reviewing the literature on studies of cement-bentonite interactions. The major bentonite alteration by hyperalkaline fluids produced by the interaction of cementitious materials with groundwater includes cation exchange, montmorillonite dissolution, secondary mineral precipitation, and illitization. When the hyperalkaline leachate from the reaction of the cementitious material with the groundwater comes into contact with bentonite, montmorillonite, the main component of bentonite, is dissolved and a small amount of secondary minerals such as zeolite, calcium silicate hydrate, and calcite is produced. When montmorillonite is continuously dissolved, the physicochemical properties of bentonite may change, which may ultimately causes changes in bentonite performance as a buffer material such as adsorption capacity, swelling capacity, and hydraulic conductivity. In addition, the bentonite alteration is affected by various factors such as temperature, reaction period, pressure, composition of pore water, bentonite constituent minerals, chemical composition of montmorillonite, and types of interlayer cations. This study can be used as basic information for the long-term stability verification study of the buffer material in the geological disposal system for high-level radioactive wastes.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.55-74
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• 2021

The role of container ports contributes greatly to international trade and national or regional economic development by supporting maritime transportation and occupies a central position in the supply chain connecting sea and land. The performance(traffic volume) of a port generally depends on geographic, economic, and operational factors etc. For the past several decades, container port volumes have grown with fluctuation. This study amis to analyze how global ports have undergone changes in terms of cargo volume by region, size and period. For the analysis, only the volumes of global top 100 ports were used. Shift-share analysis and BCG matrix analysis were employed as methodologies. According to the result of the analysis, the relative volatility of port traffic over the past 16 years as a whole was found to be limited. On the other hand, ports in China and Southeast and Southwest Asia, which are economically growing for the last decades, showed growing trends, while ports in Northeast Asia and Europe appeared to be in a stagnant or declining phase. It also shows that most of the global ports maintain limited changes in cargo volume because they are already positioned as central ports in the region. In addition, it can be seen that the global port volume has a close relationship with the change in the economic capability of the relevant region or country.