• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.3
• /
• pp.323-335
• /
• 2020

In this study, a series of site measurement of particulate and gases pollutants at five tunnels were carried out along with case studies to review the suitability of the current road tunnel ventilation design standards. Previous studies by other researchers have shown that the ratios of the level of measurement to the standard were 27.9%, 1.6% and 3.4% for TSP, CO and NOx, respectively. Those measured in this site study shows even lower ratios; the ratios were 2.6%, 0.8% and 0.3%, for TSP, CO and NOx, respectively. The particle size analysis of TSP for the five tunnels shows that PM10 including tire wear and re-suspended road dust exceeded 20.4%. This implies that non-exhaust particulate matter must be taken into account, since the current design standards for the particulate matter (visibility) include only the engine emission. Based on the recent research results, for vehicle emission rate and slope-speed correction factors, revision of ventilation design standards for pollutants is required. WRA (PIARC) also emphasizes the necessity of the ventilation design standards for pollutants. In addition, enactment of a new road tunnel ventilation system operation standard or guideline is strongly recommended when considering the low operating rate of the ventilation system with jet-fans.

• Journal of agriculture & life science
• /
• v.45 no.6
• /
• pp.265-278
• /
• 2011

Effects of the open level of the side window were studied to control the temperature and relative humidity in the fog cooling greenhouse. The greenhouse was cooled by air atomizing spray nozzles of the air and water two-fluid process. The control process includes the measuring of environmental variables, setting and coding of the water balance equations and heat balance in greenhouse, calculating of the roof window open and spray water, and operating of the motor and pump. The target temperature and relative humidity were set at $28^{\circ}C$, 75%, respectively. The three modes of the side window open level were 0%, 50% and 100%. The average dry bulb temperatures of the inside air were 28.2, 27.2 and $26.3^{\circ}C$, respectively and their standard deviation was ranged from $0.4^{\circ}C$to $0.8^{\circ}C$. Also the relative humidity of the 0% mode was the best controlled one with the average of 76.3% and the standard deviation of 2.1%.

• Korean Journal of Plant Resources
• /
• v.32 no.5
• /
• pp.589-614
• /
• 2019

To investigate the distribution of vascular plants growing at Mt. Guryong, we surveyed from March in 2016 to October in 2017. The flora of Mt. Guryong was classified as a total of 526 taxa comprising of 87 families, 298 genus, 449 species, 4 subspecies, 63 varieties, 10 forma. Among them, the endemic plants in Korea were investigated as 10 taxa of including Pseudostellaria coreana (Nakai) Ohwi. The Korean rare plants species were investigated as 16 taxa, among them degree of CR investigated as 1 taxa of Cypripedium macranthum Sw., VU investigated as 5 taxa of including Rhododendron micranthum Turcz., degree of LC investigated 9 taxa of including Clematis koreana Kom., degree of DD investigated 1 taxa of Adenophora grandiflora Nakai. Endemic plants were investigated as 14 taxa of including seudostellaria coreana (Nakai) Ohwi and The floristic special plants were a total of 84 taxa such as 2 taxa in degree V(in cluding Polypodium virginianum L.), 7 taxa in degree IV (including Anemone reflexa Steph. & Willd.), 21 taxa in degree III(including Celtis aurantiaca Nakai), 22 taxa in degree II (including Thelypteris phegopteris (L.) Sloss.) and 31 taxa in degree I (including Cimicifuga simplex (DC.) Turcz.) was carried out to provide basic data. The naturalized plants were investigated as 37 taxa of including Chenopodium ficifolium Smith., Thlaspi arvense L., Rumex crispus L. and the percentage of urbanization index was 11.53%, the naturalized ratio was 6.99% respectively.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.4
• /
• pp.389-397
• /
• 2018

Modern countries have almost ratified the UN Convention on the rights of persons with disabilities and are creating environments to prevent discrimination against these individuals. In 1996, the International Maritime Organization presented a recommendation for the design and operation of passenger ships to respond to elderly and disabled persons' needs. In Korea, an act on the promotion of transportation convenience for mobility disadvantaged persons has been implemented, and facilities for the disabled have been rapidly installed in ships, vehicles, aircraft, railways and passenger terminals. However, the maritime transport environment is less concerned about disabled persons than safety. In this study, basic research was conducted to improve the maritime transport environment for disabled people in Korea through a field survey and literature survey. As a result, it was found that relevant laws and regulations have not been properly applied to excursion ships and ferries as well as small-scale ports, which are responsible for a large part of coastal passenger transportation. In addition to low installation rates of facilities for the transportation of persons with disabilities in ships and terminals, loose equipment was also considered. Therefore, it is necessary to protect the human rights of persons with disabilities, which are universal values of humanity, by complementing laws and introducing improved facilities.

• The Journal of the Korea Contents Association
• /
• v.21 no.9
• /
• pp.234-244
• /
• 2021

The purpose of this study is to investigate the effect of the retirement pension system on workers' retirement income security and job commitment, and to verify the mediating effect of corporate welfare satisfaction in the relationship between the retirement pension system's retirement income security and job commitment. Employees of domestic K-company, which have been implementing the retirement pension system since 2011, were surveyed, and 403 copies of the final data were analyzed using SPSS 22.0. The analysis results are as follows. First, as the sub-factors of the retirement income security, the guarantee of the retirement benefits right and the income replacement rate had a significant positive(+) effect on job commitment. Second, as sub-factors of the retirement income security, the income replacement rate and customized retirement design had a significant positive(+) effect on corporate welfare satisfaction. Third, corporate welfare satisfaction had a significant positive(+) effect on job commitment. Fourth, it was found that the relationship between the income replacement rate and job commitment, which are sub-factors of retirement income security, is mediated by diversity and the level of benefits, sub-factors of corporate welfare satisfaction. Based on the results of this study, it was confirmed that the implementation of the retirement pension system enhances the employee's job commitment and corporate welfare satisfaction, and is also important for corporate management.

• KIPS Transactions on Software and Data Engineering
• /
• v.10 no.9
• /
• pp.359-366
• /
• 2021

A number of construction companies in Korea invest considerable human and financial resources to construct a system for managing apartment defect data and for categorizing repair tasks. Thus, this study proposes machine learning models to automatically classify defect complaint text-data into one of the sub categories of 'finishing work' (i.e., one of the defect repair tasks). In the proposed models, we employed two word representation methods (Bag-of-words, Term Frequency-Inverse Document Frequency (TF-IDF)) and two machine learning classifiers (Support Vector Machine, Random Forest). In particular, we conducted both binary- and multi- classification tasks to classify 9 sub categories of finishing work: home appliance installation work, paperwork, painting work, plastering work, interior masonry work, plaster finishing work, indoor furniture installation work, kitchen facility installation work, and tiling work. The machine learning classifiers using the TF-IDF representation method and Random Forest classification achieved more than 90% accuracy, precision, recall, and F1 score. We shed light on the possibility of constructing automated defect classification systems based on the proposed machine learning models.

• Journal of the Korean Society of Radiology
• /
• v.15 no.2
• /
• pp.219-227
• /
• 2021

This study examines the status of non-face-to-face online continuing education for radiological technologist working at medical institutions in a region, their satisfaction, and completion status, and provides basic data on the design and operation of continuing education predicted after the post-coronavirus. It was implemented to do. From January 5, 2021 to January 31, 2021, 255 radiological technologist license holders who completed online continuing education in 2020 were targeted. Satisfaction with online continuing education was higher as the age, male radiological technologist, and job title increased after obtaining a license. As for the status of completion of continuing education, the higher the age, the higher the percentage of regular members belonging to the branch, the more moderate the cost of continuing education of medical institutions was guaranteed, and the more the completion of the continuing education license and the recognition of legal restrictions. Based on the results of this study, in order to increase the satisfaction and completion of continuing education, it is necessary to develop various educational programs and contents according to age in preparation for the rapidly changing medical environment, and it is necessary to identify and provide members' needs.

• Ecology and Resilient Infrastructure
• /
• v.8 no.4
• /
• pp.273-280
• /
• 2021

In the past, the government made a total of 357 hydrophilic districts into parks to create rest areas in the national river with the four major river projects. According to the results of the survey, 60 water-friendly districts with low utilization were lifted in January 2017, and 297 water-friendly districts are currently being managed. Local governments are in charge of the maintenance costs necessary to maintain these hydrophilic districts, which require considerable costs, so it is necessary to accurately grasp the characteristics and needs of local residents at the operation stage after designation. In this study, the characteristics of local residents in the hydrophilic district were analyzed by correlating social factors with river users, crawling social network data to analyze visit patterns, and derived related Keywords, and analyzed the characteristics of the hydrophilic district. The study target areas are Samrak and Daejeo Ecological Park, located downstream of the Nakdonggang River. Social factors analyzed real estate transaction price data, economic activity income, households, stress perception rate, and pet breeding status through public data provided by Statistics Korea, and analyzed user visit patterns and image keywords on weekends.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.6
• /
• pp.1147-1159
• /
• 2018

This study focuses on the verification of a rapid protection automation system using an inflatable structure. The inflatable structure is an automatic rapid protection system against human and material damage when the subsea tunnel is flooded. Especially, it is essential for construction and operation of subsea tunnels. In this study, we have experimentally verified the rapid protection automation system using the inflatable structure designed for this problem. In order to verify this, a model tunnel with a 40: 1 reduction ratio was constructed, and air pressure of 0.1 bar and 0.15 bar was injected to divide the tunnel according to the expansion rate at 10 sec and 20 sec. According to the results of the study, the protection efficiency was better at 0.15 bar than 0.1 bar when the expansion structure was expanded, and the protection efficiency and influent control efficiency were different according to the pneumatic injection time of the inflating structure. As a result of this study, it was found that the higher the internal air pressure of the inflated structure and the faster the inflation of rate, the more effectively the inflated structure was inflated. As a result of this study, it is necessary to further study the wedge type structure which is useful for the storage method of expansion structure, shape and expansion derivative, inhibition of expansion structure during protection and control of inflow water.

• Journal of Conservation Science
• /
• v.34 no.6
• /
• pp.481-492
• /
• 2018

We conducted TL/OSL dating for the earthenware kilns in the Bongsan-ri archaeological site, Osong, which was occupied from the late nineteenth to the late twentieth century. With the SAR-TL/OSL method, paleodose was determined from the equivalent dose during the burial period($ED_{burial}$), the background dose($ED_{BG}$), the fading correction factor(f), and the overestimation correction factor(C). The annual dose rates and their provenance were evaluated from the measurement of natural radionuclides $^{238}U$, $^{232}Th$, and $^{40}K$. Because the comprehensive absolute age was provided by combining the resulting TL/OSL and radiocarbon data, we concluded that, for the absolute chronology of a modern archaeological site, TL/OSL dating and radiocarbon dating must be carried out together and summed. The construction and occupation of earthenware kilns in the Bongsan-ri site had changed from stage I (No.5, 6 kilns), to stage II (No.1, 2, 3 kilns), to stage III (No.4) in chronological order. When Bayesian statistics were applied, we found that the absolute ages of occupation for stages I, II, and III correspond to AD $1910{\pm}23$, AD $1970{\pm}10$, and AD $1987{\pm}4$. These results were in good agreement with the archaeological context or chronology.