• Korean Journal of Construction Engineering and Management
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• v.25 no.5
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• pp.15-24
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• 2024

System support is a facility that is temporarily installed to support vertical loads at construction sites, and is assembled and installed by reused individual members. These characteristics are likely to lead to poor performance of installed system supports, and even though it is institutionalized to check structural safety at the their design phase, accidents continue to occur at the construction site. Accordingly, safety management of system support is implemented through various institutional methods, but the current system does not consider the performance degradation of temporary facilities due to the reuse of individual temporary members. Therefore, the purpose of this study is to verify the performance of assembled system support. In order to do achieve this purpose, the authors divided individual system supports into unused and used groups and performed compression performance test with defined models assembled with those two groups of system supports. The results of this study are expected to be meaningful as a research case that can quantitatively evaluate safety systems and standards for the performance of existing temporary facilities and suggest directions for improving the safety management system of temporary facilities in the future.

• Land and Housing Review
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• v.15 no.3
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• pp.97-111
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• 2024

Greenhouse gas emissions and environmental pollution persist globally, leading to an increase in extreme weather events, such as floods and droughts. Previous studies have investigated various factors for energy consumption, such as household, residential, economic, and social characteristics. However, the body of research examining energy-saving behavior and perceptions remains limited and underexplored. In particular, significant differences in energy conservation perceptions can be observed among individual household members, even within the same household. To this end, this study explores how household energy consumption is associated with various factors, including household characteristics, housing characteristics, energy-saving behaviors, and seasonal factors. We utilize survey data from the Household Energy Panel, spanning a 24-month period from January 2018 to December 2019, comprising a sample of 5,897 households across 17 cities and provinces nationwide. The findings of this study are expected to offer an empirical evidence for household energy-saving policies.

• Journal of Korea Port Economic Association
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• v.40 no.2
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• pp.39-52
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• 2024

As the 'Eco-friendly conversion project for Port's CHE(Cargo handling Equipment) ' which has started in 2014 ends in 2024, in addition to the existing 'Low pollution' paradigm to respond to fine dust problems, a full-fledged 'Zero-emission' conversion is to be required to implement 2050 carbon neutrality at the port level. Accordingly, this study calculated the future replacement demand for container handling equipments at the four major domestic ports(Busan, Incheon, Yeosu Gwangyang, and Ulsan), and assumed a scenario where every CHE supposed to eb replaced is electrified inturn every year. And then the resulting future emission reduction effect accordingly was calculated and analyzed. In particular, compared and analyzed the emission outlook applying the life-cycle concept(LCA), which is being adopted as a new emission calculation standard in most industrial fields, and the existing emission calculation concept that only considers direct emissions within the port, to provide more effective implications for the promotion of follow-up conversion projects. According to the analysis results, if the CHE is replaced according to the proposed schedule, it is expected that the existing emissions can be reduced by 79% compared to BAU in 2025 and 97.4% in 2030. However, if the LCA is applied, it is expected to be reduced by only 27.6% by 2030. This suggests that port's CHE must be converted to zero emissions and at the same time establish an Ports' self-sufficient energy grid based on renewable energy.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.42 no.1
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• pp.14-21
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• 2024

This research focuses on the restoration of stone structures situated within the landscaping facilities at royal palace and tomb heritages of the Joseon Dynasty, emphasizing their considerable importance in terms of scale and their contribution to the landscape's aesthetic form. The study conducts its analysis through the lens of three critical value attributes the form and design of the structures, the materials and textures used, and the traditional techniques employed. The subject of the study is the Gonshinji Pond, the pond and royal canal at Yeongneung and Nyeongneung, the royal canal at Gyeongbokgung Palace, and the flower steps at Yeongchunheon and Jipbokheon. Finding instances of stone wall repairs that complied with the established standards for cultural heritage repair proved challenging. Nonetheless, adherence to these norms and a methodical approach to deducing the original structure were evident in the most recent restoration cases. This discovery is likely to have considerable implications for the approach to future stone wall repair and restoration efforts. There's a clear need for the development of detailed guidelines and handbooks that thoroughly document the restoration process for stone walls, as outlined in repair reports.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.267-277
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• 2014

Objective of this paper is to assess the available data on the pesticide uses and regulations in the golf courses, and provide the nationwide systematic management options. Numbers of golf courses in Korea are rapidly increasing from 2000s and reached at 421 sites by the end of 2011. Accordingly pesticide usage has been increased with years in direct proportion to the increasing number of golf courses. Amounts of pesticide applied in 2011 were 118,669 kg as of an active ingredient and were in the orders of fungicides (54.9%) > insecticides (24.4%) > herbicides (13.3%) > growth regulators (0.1%). Average pesticide usages in 2011 were 280.9 kg per golf course and $5.4kg\;ha^{-1}$. Frequencies of the residual pesticide detections in green and turf were higher than those in fairway and soil, respectively. Residue of highly toxic pesticides was not detected in golf courses. Ministry of Environment in 2010 has developed the 'golf course pesticide monitoring and management system' which is the advanced online registry for kind and amount of pesticides applied in each golf course. This system is intended for monitoring of the pesticide uses and residual levels and protecting the environmental pollution from pesticides in the golf course. In 2009, management of pesticides in the golf courses became the task of Ministry of Environment, being merged from many federal agency and ministries. The protocol for the site-specific best management practices, on which to base results from the risk assessment, should be set for pesticides in the golf to minimize the environmental impacts.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.667-676
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• 2007

This study was conducted to determine effects of cellulolytic microbes inoculation to sawdust-based spent mushroom substrate(SMS) during deepstacking on fermentation parameters, total microbial counts and cellulolytic enzyme activity and to on SMS nutrients utilization by sheep. For sheep metabolism trials, six sheep(ram, average 54.8kg) were fed a Control diet(70% concentrates, 15% rice straw and 15% SMS with no microbial treatment on a dry basis) and a Treatment diet(the same diet including SMS with a microbial treatment) for 2 trials. Spent mushroom substrates with or without a microbial(4 strains including 1 strain of Enterobacter ludwigii, 1 strain of Bacillus cereus and 2 strains of Bacillus subtillis) treatment (1% of SMS on wet basis) were deepstacked for 7 days. The internal temperatures in 1.2 M/T of SMS deepstacks reached to 50±5℃ within 7 days of storage. Total microbial counts remarkably decreased (P<0.05) with a deepstacking process and were not affected(P>0.05) by the microbial treatment. For fibrolytic enzyme activity, CMCase and xylanase activities were decreased(P<0.05) by a deepstacking process. After deepstacking, the microbial treatment showed about 2.5-times higher(P<0.05) for CMCase activity and about 4-times higher(P<0.05) for xylanase activity than those of the Control. Activities of ligninolytic enzymes such as laccase and MnP were not affected by the microbial treatment. The sheep fed the microbially treated SMS diet had a tendency of greater total tract digestibilities of ash(P=0.051), NFE (P=0.071), hemicellulose(P=0.087) and NDF(P=0.096) than those fed the untreated SMS diet. Nitrogen balance of sheep was not affected(P>0.05) by feeding of microbially treated SMS. Accordingly, these results indicate that cellulolytic microbes inoculation during deepstacking of SMS may improve the bio- utilization of SMS by sheep.

• Sleep Medicine and Psychophysiology
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• v.20 no.1
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• pp.35-40
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• 2013

Objectives: The aim of this study is to evaluate the polysomnographic characteristics and prescription status of restless legs syndrome (RLS) patients in naturalistic setting. Methods: We reviewed medical record of the patients over 18 years olds who (i) satisfied the clinical RLS diagnostic criteria and (ii) had the polysomnography and got treatment related thereto. As a baseline, we evaluated the four diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG) and the International Restless Legs Scale (IRLS) of the subjects. Then the polysomnography and the suggested immobilization test (SIT) were conducted and, after one month of pharmacotherapy using dopamine agonist, the IRLS was evaluated again. Results: A total of 211 subjects participated in this analysis and 94 (44.5%) of them were male and the other 117 (55.5%) were female and the average age of the 211 subjects was $46.9{\pm}14.2$. Out of such 211 subjects, 136 subjects (64.5%) also had the obstructive sleep apnea (OSA), and 53 subjects (25.1%) also had the periodic limb movement disorder (PLMD). 185 subjects (87.7%) out of the 211 subjects had some other sleep disorders except RLS. The results of the polysomnography were as follows : 78.0% of sleep efficiency, 86.8 min of wake after sleep onset, and 3.4% of N3. More specifically, 12.4/h of the average apnea hypopnea index, 14.8/h of the periodic limb movement during sleep (PLMS), 41.2/h of the periodic limb movement during wake during SIT and 21.6/h of total arousal index during sleep. Out of the total subjects, 149 (70.6%) of them took the ropinirole and 47 (22.3%) of them took the pramipexole, and the average dosage of ropinirole was 0.9mg(dosage range 0.125-5 mg) while the average dosage of pramipexole was 0.5 mg (dosage range 0.125-4 mg). The dosage of the ropinirole showed a significant positive correlation with the age (r=0.25, p=0.002) and also with the IRLS (r=0.23, p=0.038). The IRLS at the baseline was 24.9 while the same was decreased down to 13.4 after one month. Conclusions: Analyzing the result of this study, a majority of clinical RLS subjects demonstrated comorbidity with some other sleep disorder such as the OSA or PLMD. 25.1% of the subjects showed a PLMD, which was less than in previous researches and the average PLMS was not very high as 14.8/h. The dosage of dopamine agonist taken was often a bit more than the amount recommended in Korea. A prospective research using a large scale controlled subjects will be necessary with respect to this topic.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.4
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• pp.172-186
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• 2017

Current study is a part of the efforts to assess the estuarine barrage effects on the coastal ecosystem induced by the Si flux changes. Surface sediments from Seomjin and Nakdong estuary and sediment cores from Nakdong estuary was analysed to investigate the effect of estuarine barrage on the distribution of grain size, organic matter (loss on ignition: LOI) and biogenic silica (BSi). The samples of Seomjin estuary were collected in March, 2015 and those of Nakdong estuary were collected in November, 2014. Generally, the longitudinal distribution of grain size, LOI and BSi in Seomjin estuary, natural estuary, was gradually changed. However mud (silt and clay), LOI and BSi increased from station mid-estuary where tide reaches year-round. The distribution of grain size, LOI and BSi in Nakdong estuary, however, were entirely different between inside and outside of estuarine barrage. The mud percentage and LOI were low and consistent in inside of the barrage except R05, inside of right gate, yet those of outside of the barrage were higher and varied by adjacent sluices. Mud, LOI and BSi of ND1 and ND2 decreased immediately after the construction of Nakdong estuarine barrage due to disturbance of sediment and decrease of sediment supply. To exclude the physical effects by the barrage, BSi excess ($BSi_{exc}$) was calculated using regression equation of BSi-LOI and BSi-mud of Seomjin estuary. $BSi_{exc}$ of Seomjin estuary decreased gradually from upper estuary to lower estuary. $BSi_{exc}$ of Nakdong estuary were positive in inside of the barrage and negative in outside of the barrage. BSi retention and shift of species composition of diatom by the barrage would affect $BSi_{exc}$ distribution. Before the construction of Nakdong estuarine barrage, $BSi_{exc}$ of ND2 was negative and consistent owing to high mud sedimentation. After the construction, $BSi_{exc}$ of ND2, however, fluctuated due to continuous disturbance of sediment due to construction of Eulsuk bridge and East gate.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.85-92
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• 2005

The performance of a novel fermentation process, adopting a sludge blanket type configuration for higher hydrolysis/acidogenesis of the municipal primary sludge, was investigated under batch and semi-continuous conditions with various pH and temperature conditions. This acid elutriation slurry reactor provided higher system performance with a short HRT (5 days) and higher acidogenic effluent quality under pH 9 and thermophilic ($55^{\circ}C$) conditions. The hydrolysis of the sludge was revealed to be significantly dependent on seasonal effects for sludge characteristics but with little impact on acidogenesis. Based on the rainy season at the optimum conditions, VFA production and recovery fraction ($VFA_{COD}/COD$) were $0.18\;g\;VFA_{COD}\;g^{-1}\;VSS_{COD}$ and 63%. As byproducts, nitrogen and phosphorus releasing were $0.006\;g\;N\;g^{-1}\;VSS_{COD}$ and $0.003\;g\;P\;g^{-1}\;VSS_{COD}$, respectively. For the mass balance in a full-scale plant($Q=158,880\;m^3\;day^{-1}$) based on the rainy season, the VFA and non-VFA(as COD) production were $3,110\;kg\;VFA_{COD}\;day^{-1}$ and $1,800\;kg\;COD\;day^{-1}$, resulting in an increase of organics of $31\;mg\;COD\;L^{-1}$ and $20\;mg\;VFA_{COD}\;L^{-1}$ and nutrients of $0.7\;mg\;N\;L^{-1}$ and $0.3\;mg\;P\;L^{-1}$ in the influent sewage. The economical benefit from this process application was estimated to be about $67 per $1,000m^3$ of sewage except for energy requirements and also, better benefits can be expected during the dry season. Also, the results revealed that the process has various additional advantages such as pathogen-free stabilized solids production, excellent solids control and economical benefits.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.165-190
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• 2008

The degree of informational asymmetry relating to the expiration of index derivatives is usually increased as an expiration day of index derivatives approaches. The increase in the degree of informational asymmetry may have some effects on trading behavior of investors. To examine what the effects look like, 'life cycle of index derivatives' in this study is defined as three adjacent periods around expiration day: pre-expiration period(a week before the expiration day), post-expiration period(a week after the expiration day), and remaining period. It is inspected whether stock investor's trading behavior is changed according to the life cycle of KOSPI200 derivatives and what the reason of the changing behavior is. We have four results. First, trading behavior of each investor group is categorized into three patterns: ㄱ-pattern, L-pattern and U-pattern. The level of trading activity is low for pre-expiration period and normal for other periods in the ㄱ-pattern. L-pattern means that the level of trading activity is high for post-expiration period and normal for other periods. In the U-pattern, the trading activity is reduced for remaining period compared to other periods. Second, individual investors have ㄱ-pattern of trading large stocks according to the life cycle of KOSPI200 index futures while they show U-pattern according to the life cycle of KOSPI200 index options. Their trading behavior is consistent with the prediction of Foster and Viswanathan(1990)'s model for strategic liquidity investors. Third, trading pattern of foreign investors in relation to life cycle of index derivatives is partially explained by the model, but trading pattern of institutional investors has nothing to do with the predictions of the model.