• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.12-20
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• 2020

The demand for maintenance of underground facilities buried beneath the road continues to increase significantly, due to environmental problems caused by excessive noise and dust and complaints from urban residents, the demand for eco-friendly and low-noise road cutters is increasing. Therefore, we analyzed the cutting performance of low noise cutter and eco-friendly cutter and reviewed the improvement. Based on the field construction cases, problems and improvements were obtained according to the cutting machine working procedure. The productivity for cutting operations of eco-friendly cutters (36.0 seconds/m) was somewhat improved compared to the low noise cutters (37.6 seconds/m). However defects occurred in some sections and improvement was required.

• Journal of the Korean Geotechnical Society
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• v.37 no.9
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• pp.37-50
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• 2021

Recently, due to the expansion of urban infrastructure using underground spaces in urban areas, many adjacent constructions and excavations have been made carried out between existing facilities, and complaints related to the stability of existing facilities due to close construction have become significant issues. In this study, it was closely reviewed for the existing metro tunnel structure in the new Dongbuk urban metro railway to determine the behavioral characteristics of tunnel structure according to adjacent tunnel construction. Also, it was analysed the evaluation of the safety zone and excavation method for metro tunnel structure. And after a detailed damage assessment, track irregularities and structural calculation by using a numerical analysis, stability of the metro tunnel structure according to nearby tunnel excavation was evaluated to be secured for safety. This study is expected to be applied as practical reference to review the evaluation of safety effects of existing tunnel structure and buildings according to adjacent construction in complex deep urban tunnelling.

• Explosives and Blasting
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• v.39 no.2
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• pp.15-26
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• 2021

Domestic electronic detonators are used widely in many quarry and construction sites since its launch at 2013. In the case of SOC projects conducted in the city, most of them are designed in high-depth to reduce complaints. The high-depth excavation needs a long construction period and huge cost for building shaft and ventilation hole. Mechanical excavation method is applied when safety things are located nearby the site. Solidity of rock and machine's performance affect on the method's efficiency. So as the efficiency is getting lower, the construction period is extended, and the cost is increases as well. This case study is about changing the machine excavation method to the blasting method which is electronic detonator applied at the shaft construction site in the city. This is an example of using electronic detonators on the construction site in reducing blast-noise and vibration while meeting environmental regulatory standards.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.671-679
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• 2022

Harmful factors such as shock waves and fragments are generated at domestic ammunition testing sites and military shell shooting training sites due to frequent shooting and explosion tests. As a result, complaints from local residents are rapidly increasing, and there is a high risk of damage to facilities and human life. The recently constructed ammunition test site built a test facility for firing artillery and rocket propulsion in a narrow area with a radius of 300 m due to site restrictions, but damage to the facility is accumulating because there is no adequate protective structure. Therefore, in this study, quantitative data on harmful factors such as noise, vibration, shock wave, and thermal effect generated between artillery firing and rocket propulsion tests were measured, and explosion pressure characteristics were analyzed to design a protective structure, and use Autodyn to protect performance. to perform verification.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.393-402
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• 2021

The first TBM introduced in Korea was the gripper TBM, which was applied to the Gudeok Waterway Tunnel in 1985. In the initial stage of the introduction of the gripper TBM, many applications were mainly focused on waterway tunnels (Tunnel Mechanized Construction Design, 2008). Currently, the construction range of gripper TBM in Korea is widely applied to not only waterway tunnels, but also subways, railway tunnels, and TBM+NATM expansion. Overseas, gripper TBM is generally applied, and even when NATM tunnel is applied, it is applied as an exploration tunnel because of the excellent advance rate of gripper TBM and used as an evacuation tunnel after completion. Due to the fast excavation speed, the application of the gripper TBM in the rock section of weathered rock or higher can minimize the environmental and civil complaints caused by creating a large number of work areas when planning long tunnels or mountain tunnels. In this study, the work process of the general gripper TBM was analyzed by analyzing the construction cycle and the gripper TBM with a diameter of 2.6~5.0 m, which was applied the most in Korea. Downtime was investigated and analyzed.

• The Journal of Sustainable Design and Educational Environment Research
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• v.22 no.1
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• pp.13-27
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• 2023

This study analyzed the reasons for extending the construction period considering factors such as the quality of construction materials, safety and cost-effectiveness of construction, size of construction, academic schedule, and local conditions (complaints) when determining the appropriate period for school construction projects tailored to a specific region or educational office. Based on the example of construction projects for school facility improvement by education office A, this study conducted a case study to identify the motives for construction period extension. To determine the appropriate construction period for school facilities, this study conducted a comprehensive review of construction projects under the jurisdiction of education office A, examined data from the Meteorological Data Open Portal, and performed advanced statistical analysis. Future case studies must determine the appropriate construction period for school facilities in a rational and systematics.

• Clean Technology
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• v.18 no.4
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• pp.379-389
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• 2012

Environmental issues are being paid more attention due to income growth, urban overcrowding, and population growth in Korea. Among the various environmental problems, odor damage is the one of the serious factors. To take example for food waste combination treatment in Su-young wastewater treatment plant in Busan, many complaints occurred because this plant locate around residential areas. The purpose of this work is not only to analyze odorous elements and their contributions but also to evaluate odor quotient (OQ), sum of odor quotient (SOQ), and treatment efficiency of bio-filter. The results of dilution sensory test of complex odor, grinder, leachate, hopper indicated higher order complex odors happen in July and August. The main odorous elements consisted of hydrogen sulfide, ammonia, methly mercaptan and acetaldehyde, which were analyzed by instrumental detection method, and methyl mercaptan was exceeded over 3,571 times of threshold. In addition, result of contribution of odor was methyl mercaptan (49.95 to 59.08%), hydrogen sulfide (20.43 to 29.27%), trimethylamine (8.82 to 13.42%) and acetaldehyde (9.17 to 11.35%). Other facilities were compared with the contribution of the odor using OQ and SOQ during the process. Sulfur compounds, acetaldehyde, and trimethylamine are high contribution of odor using OQ as well as odor intensity of grinding process is highest. As a result, sulfur compounds (e.g., methyl mercaptan and hydrogen sulfide) are highest for OQ and SOQ of grinding process is highest as 7,067. The removal efficiency of deodorization equipment was more than 90.00% in ammonia and amines, but the average efficiency of sulfur compounds was 53.51%. Thus, this facility is more higher contribution of acetaldehyde and trimethylamine than other treatment facilities. And food waste treatment in environmental area needs to consider appropriate capacity and refers to other bio-filter operating conditions.

• Research in Community and Public Health Nursing
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• v.1 no.1
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• pp.299-317
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• 1989

This study was attempted to find out the distribution of industrial nurses, analyze job performance by function and utilization state of medical dispensary among workers. The subjects for this study were 32 nurses working at industry located in Kyungpook and Taegu area. The data was collected through questionaire during the period of August 5-31, 1986, and analysed by the method of frequency and percentage. The following is the main findings of the study; 1. 72.2% of respondents was engaged in manufacturing industry, 33.3% in workplace whose regular workers was more than 2,000 workers. 67.7% in occupational health physicians was part-time system. 2. 93.1% of respondents was 20-29 years age group, 93.1% was graduates of junior nursing college, 96.6% was unmarried. 448% had 1-4 years of total working experiences. 3. For the motives which made them becomes industrial health nurse, 'good employment condition' was 62.1%. For the job satisfaction, 'moderate' was 586%. For the interest about the industrial health, 'moderate' was most frequent (58.6%). In the inservice education, 86.2% of the subjects was received education. 4. For the attitude of the dispensary and industrial nursing of employer, 'necessary' was most frequent (72.4%, 62.6%). 5. All establishment had dispensary facilities, 65.5% of them had independent dispensary. 6. In duty shift, 93.1% of respondents was working in one shift system. 41.4% of respondents was received from 250,000 won to 290,000 Won and 41.4% was belong to personnel section and 24.1% was direct controlled by general business section chief. 7. In the main health problem of their factories, 48.3% of respondents was work-environmental state, 24.1% was health education. 8. In the Dispensary budget, 60% of respondents was under 3,000 won per worker. 9. In the job performance rate by function, nursing service 73.1%, industrial health and nursing management 63.7%, environmental hygiene and safety management 54.5%, medical insurance 44.9%, welfare 38.4%. 10. Main health complaints among workers utilizing medical dispensary was 35.9% of respiratory system, 21.5% of gastro-intestinal system, 11.0% of skeletomuscular system.

• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.25-32
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• 2020

The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.

• Journal of Distribution Research
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• v.6 no.1
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• pp.1-21
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• 2001

This study introduced the components of apparel store, which include product and service factor to reflect the modified conception of service. The purposes of this study were to investigate the dimensions of the components of apparel store and to examine consumers' rating of importance on the components of apparel store. In addition, this study explored the effect of clothing involvement and demographic variables on importance perception. Data were collected via a questionnaire from young adult females in their twenties. The results of this study revealed five dimensions of service factor: environmental service, salesperson service, attitude and policy service related to exchange and refund, policy service related to promotion, and policy service related to convenience. Factors related to product were identified price, quality, variety, fashion, design and brand. Attitude and policy service related to exchange and refund is the most important factor that consumer perceived. Salesperson service and product quality were the second important factors. The relatively important factor in each service dimension was this : display in the environmental service, the ability of salesperson to resolve customer's complaints in the salesperson service, sales person’s courtesy in managing exchange or refund in policy service. Clothing involvement and demographic variables do affect consumers’perception on importance.