• Journal of Wetlands Research
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• v.24 no.4
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• pp.345-353
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• 2022

A wastewater treatment plant (WWTP) is a major gateway for the engineered nano-particles (ENPs) entering the water bodies. However existing studies have reported that many WWTPs exceed the No Observed Effective Concentration (NOEC) for ENPs in the effluent and thus they need to be designed or operated to more effectively control ENPs. Understanding and predicting ENPs behaviors in the unit and \the whole process of a WWTP should be the key first step to develop strategies for controlling ENPs using a WWTP. This study aims to provide a modeling tool for predicting behaviors and removal efficiencies of ENPs in a WWTP associated with process characteristics and major operating conditions. In the developed model, four unit processes for water treatment (primary clarifier, bioreactor, secondary clarifier, and tertiary treatment unit) were considered. Additionally the model simulates the sludge treatment system as a single process that integrates multiple unit processes including thickeners, digesters, and dewatering units. The simulated ENP was nano-sized TiO₂, (nano-TiO₂) assuming that its behavior in a WWTP is dominated by the attachment with suspendid solids (SS), while dissolution and transformation are insignificant. The attachment mechanism of nano-TiO₂ to SS was incorporated into the model equations using the apparent solid-liquid partition coefficient (Kd) under the equilibrium assumption between solid and liquid phase, and a steady state condition of nano-TiO₂ was assumed. Furthermore, an MS Excel-based user interface was developed to provide user-friendly environment for the nano-TiO₂ removal efficiency calculations. Using the developed model, a preliminary simulation was conducted to examine how the solid retention time (SRT), a major operating variable affects the removal efficiency of nano-TiO₂ particles in a WWTP.

• Journal of Nutrition and Health
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• v.53 no.6
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• pp.613-628
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• 2020

Purpose: The purpose of the study was to identify the health anxiety issues of middle-aged women, their health-promoting behavior, and quality of life as well as to examine the relationship between these variables. Methods: The participants were 334 women in Jeonbuk area. Demographic characteristics, the status of health anxiety, health-promoting behavior, and life quality was assessed using a self-administered questionnaire. The data were analyzed using a t-test, analysis of variance, Duncan test, and hierarchical regression analysis with SPSS ver. 24.0. Results: The score for health anxiety was 37.64 points out of a possible score of 60, and the score for health-promoting behavior was 79.18 points out of a possible score of 115. The score for the quality of life was 101.18 points out of a possible score of 150. The health anxiety scores showed significant differences, varying as per body mass index (BMI) (p < 0.05), income (p < 0.05), occupation (p < 0.05), disease (p < 0.05), satisfaction with weight (p < 0.05), and interest in weight control (p < 0.05). The health-promoting behavior showed significant differences according to age (p < 0.01), BMI (p < 0.01), income (p < 0.05), menses (p < 0.05), intake of dietary supplements (p < 0.05), perception of body image (p < 0.05), and satisfaction with weight (p < 0.05). The quality of life showed significant differences according to BMI (p < 0.05), income (p < 0.01), education level (p < 0.05), occupation (p < 0.05), disease (p < 0.05), and satisfaction with weight (p < 0.05). Regression analysis showed that health-promoting behavior was the most influential variable on the quality of life, followed by disease and health anxiety. Conclusion: Based on these results, we conclude that it is necessary to consider educational programs on improving the quality of life of middle-aged women according to the health anxiety levels and health-promoting behavior.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.277-291
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• 2021

Purpose: This study was undertaken to identify the alcohol drinking status of industrial workers, their health care practice, and dietary behavior, as well as their nutrient intake. Methods: In July 2019, 220 male subjects working in the Chungnam area were enrolled in the study. Their alcohol drinking status was evaluated by applying the Alcohol Use Disorder Identification-K (AUDIT-K) system. Demographic characteristics, status of health care practice, and dietary behaviors were assessed using a self-administered questionnaire; nutrient intakes were analyzed using 24-hour recalls. Data were analyzed by applying χ²-test, ANOVA, Duncan test, and Pearson's correlation analysis with SPSS v. 25.0. Results: Workers were classified by their alcohol drinking status as 'normal' (84, 38.2%), 'problem drinker' (45, 20.5%), 'alcohol dependence I' (60, 27.3%), and 'alcohol dependence II' (31, 16.0%). The alcohol drinking status showed significant differences with age (p < 0.05), monthly income (p < 0.05), smoking status (p < 0.05), and need for weight control (p < 0.05). Moreover, increased alcohol intake resulted in significantly decreased levels of health care practice and dietary behaviors (p < 0.05, p < 0.01, respectively). The energy intake was highest in the 'alcohol dependence I' group, followed by 'alcohol dependence II', 'problem drinker', and 'normal drinker' (p < 0.05). Intakes of vitamin E, vitamin C, and niacin in the 'alcohol dependence I' group were found to be higher than the other groups (p < 0.05). A negative correlation was obtained between alcohol drinking status, health care practice, and dietary behaviors, whereas a positive correlation was determined between alcohol drinking status, energy and water intakes. Conclusion: Considering these results, we conclude the necessity to consider nutritional and alcoholic education programs for improving the quality of work life of industrial workers, based on their alcohol drinking status.

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.52-61
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• 2011

Whereas recent researches have elucidated the positive ecological roles of large wood (LW) in fishbearing channels, LW is also recognized as a negative factor of log-laden debris flows and floods in densely populated areas. However in Republic of Korea, no study has investigated longitudinal variations of LW distribution and dynamic along the stream corridor. Hence to elucidate 1) physical factors controlling longitudinal distribution of LW and 2) their effect on variation in LW load amount, we surveyed the amount of LW with respect to channel morphology in a mountain stream, originated from Mt. Ki-ryong in Inje, Gangwondo. Model selection in the Generalized Linear Model procedure revealed that number of boulder (greater than or equal to 1.0 m in diameter), bankfull channel width and their interaction were the best predictors explaining LW load volume per unit channel segment area (unit LW load). In general, boulders scattered within small mountain streams influence LW retention as flow obstructions. However, in this study, we found that the effect of the boulders vary with the channel width; that is, whereas the unit LW load in the segment with narrow channel width increased continuously with increasing boulder number, it in the segment with wide channel width did not depend on the boulder number. This should be because that, in two channels having different widths, the rates of channel widths reduced by boulders are different although boulder numbers are same. Our findings on LW load varying with physical factors (i.e., interaction of boulder number and channel width) along the stream corridor suggest understanding for longitudinal continuum of hydrogeomorphic and ecologic characteristics in stream environments, and these should be carefully applied into the erosion control works for systematic watershed management and subsequent disaster prevention.

• (The)Study of the Eastern Classic
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• no.32
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• pp.129-158
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• 2008

After Four-Seven debate in late 16C, Korean Neo-Confucian scholars had developed their theories on human nature and morality such as Insimdosimsoel (theories on the moral emotion and desire), Inmulsoengron(theories on human nature and animal nature), Mibalsimcheron(theories on the calm mind as the embodiment of morality). Confucian scholars had been active member of society since acceptance of Neo-Confucianism. They had the plans of social reforms on the basis of moral self cultivation from the elite Confucians to commoners. So the Confucian scholar took part in the foundation of new Confucian kingdom, the Joseon Dynasty(1392). Kwon gun(1352~1409), the famous Neo-Confucian scholar wrote Iphakdosoel(pictogram for beginer of Neo-Confucianism) which emphasized the importance of moral self cultivation and that the mandate of heaven in human nature is identical with Li, the moral principle which the origin of the human intrinsic moral ability as the basis of unity with man and heaven. He thought that ethical life is identical with mandate of heaven, so he insisted all the member of society should follow Li, the moral principle which the origin of human morality and social goodness. Also he emphasized the morality was the intrinsic and most important value of human being. Therefore ethical life became essential part of self cultivation. Joeng Ji-un(1509~1561) wrote the Chunmyongdosoel (pictogram of mandate of Heaven), the start point of Four-Seven debate in mid 16C. Joeng followed Kwon's theoretical line. He emphasized the importance of moral self cultivation and the human intrinsic moral ability. He wrote that the Four moral emotions arise from Li, the moral principle of mind, while Seven emotions arise from Ki, vital force of body. He insisted that human being should control Ki, the vital force to follow the Li, the moral principle of mind. This Korean Confucian scholars developed theories of morality and self cultivation. This theories not only show the philosophical speculation of Korean Confucian scholars but also show the social idealism and moral utopianism which grounded on the human morality. So they had trust in human morality which can guide human being into the right track to the good and peaceful society. These tendencies are main characteristics of Korean Neo-Confucianism which has seen from the begining of acceptance of Neo-Confucianism. Some modern philosophical criticism which insist the Korean Neo-Confucian theories such as Four-Senven theories was indulged in academic discussion are not only neglect the historical realty but also ignore the potential of Korean Neo-Confucian heritage.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.4
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• pp.99-110
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• 2021

This study intends to examine the characteristics of the construction method of the urban water system in the historical cities of Korea, focusing on Gyeongju, Gyeongju, Goryeo, Hanyang, and Suwon Hwaseong, which were created as new towns in the late Joseon Dynasty. It examines the meaning of waterways in connection with the urban skeletal structure, focusing on the location of cities, roads, and arrangement of urban facilities, and analyzes the compositional form of the water system. We tried to derive the relationship with the structure. In particular, it can be seen that water and natural water systems act as key factors in determining the location of a city, and have a close relationship with the urban structure, urban development process, and urban structure. In addition to the symbolic meaning of water in harmony with the geographical concept, realistic demands in terms of water level and water retention are an important background. In order to respond to various demands related to water space, various planning and technical elements for managing water space were introduced in the process of city formation and development. The planning elements of the urban water system in the process of urban formation and development are summarized as follows through the analysis of the research site. First, in the process of building the urban water system in Gyeongju, Goryeo, Goryeo, Hanyang, and Hwaseong, Suwon, which were selected as the research destinations, the water system in consideration of drainage and disaster is common, but the water system construction method and usability are common. shows the difference. Second, water and natural water systems act as symbolic elements to secure the legitimacy of the city location, and as a key factor in determining the location of the city in harmony with the geographical concept and determining the left direction of the city. Third, the natural water system prior to the formation of a city works as a basis for determining the compositional form of the urban water system constructed in the process of urban formation and development in harmony with the topographical conditions. Fourth, the urban water system built on the basis of natural water systems is constructed by linking natural waterways and planned artificial waterways. Fifth, the urban water system is being built in a planned manner in consideration of the utility in connection with the urban structure, such as securing of urban land, arrangement of urban facilities and areas, composition of functional areas, and land division, in addition to the perspective of drainage system and flood control in consideration of disasters.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.1-7
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• 2022

The purpose of this study is to discuss the impact of unmanned aerial vehicle service and how to activate it. The discussion on the impact of the introduction of the unmanned aerial vehicle service was examined in terms of economic, environmental, and social acceptance, and a plan to revitalize the industry was presented. In terms of economic impact, if transportation services are increased using unmanned aerial vehicles in the future, road-based transportation cargo may decrease and road movement speed may increase due to reduced road congestion. This can have a positive effect on the increase in the value of land or real estate assets, and it also provides an impact on smart city design. In terms of environmental impact, unmanned aerial vehicles (UAVs) generally move through electricity, so they emit less exhaust gas compared to other existing devices, such as vehicles and railroads, and thus have less environmental impact. However, noise can have a negative impact on the habitat in the presence of wild animals along their migration routes. In terms of social acceptability of unmanned aerial vehicles (UAV) technology, areas that are declining due to the emergence of new services may appear, and at the same time, organizations that create profits may appear, causing conflicts between industries. Therefore, it is essential to form a social consensus on the acceptance of emerging industries. The government should come up with various countermeasures to minimize the negative impact that reflects the characteristics of the unmanned aerial vehicle use service. Just as various systems such as road signs were introduced so that vehicles can be operated on the ground to secure air routes in the mid- to long-term for revitalization of unmanned-based industries, development and establishment of services that should be introduced and applied prior to constructing air routes I need this. In addition, the design and implementation of information collection and operation plans for unmanned air traffic management in Korea and a plan to secure a control system for each region should also be made. This study can contribute to providing ideas for mid- to long-term research on new areas with the development of the unmanned aerial vehicle industry.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.45-53
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• 2022

In order to improve the emission of diesel engines, natural gas-diesel dual fuel combustion compression ignition engines are in the spotlight. In particular, a reactivity controlled compression ignition (RCCI) combustion strategy is investigated comprehensively due to its possibility to improve both efficiency and emissions. With advanced diesel direct injection timing earlier than TDC, it achieves spontaneous reaction with overall lean mixture from a homogeneous mixture in the entire cylinder area, reducing nitrogen oxides (NOx) and particulate matter (PM) and improving braking heat efficiency at the same time. However, there is a disadvantage in that the amount of incomplete combustion increases in a low load region with a relatively small amount of fuel-air. To solve this, sensitive control according to the diesel injection timing and fuel ratio is required. In this study, experiments were conducted to improve efficiency and exhaust emissions of the natural gas-diesel dual fuel engine at low load, and evaluate combustion stability according to the diesel injection timing at the operation point for power generation. A 6 L-class commercial diesel engine was used for the experiment which was conducted under a 50% load range (~50 kW) at 1,800 rpm. Two injectors with different spray patterns were applied to the experiment, and the fraction of natural gas and diesel injection timing were selected as main parameters. Based on the experimental results, it was confirmed that the brake thermal efficiency increased by up to 1.3%p in the modified injector with the narrow-angle injection added. In addition, the spray pattern of the modified injector was suitable for premixed combustion, increasing operable range in consideration of combustion instability, torque reduction, and emissions level under Tier-V level (0.4 g/kWh for NOx).

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.1
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• pp.1-14
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• 2022

This study focused on examining the location characteristics of Mujang-Eupchi(茂長邑治), a traditional city of Joseon Dynasty, and shedding light on its prototype landscape. The findings were summarized as follows: Mujang-Eupchi showed a Confucian space system with Munmyo(文廟) within Hyanggyo(鄕校) in the east, Sajikdan(社稷壇) in the west, Seonghwangsa(城隍祠) in the fortress and Yeodan(厲壇) and Seonghwangdan(城隍壇) in Jinsan(鎭山) in the north around the Mujang-Eupseong(茂長邑城), an old fortress, built in the 17th year of King Taejong(1417). It seemed that Seonghwangdan located in Jinsan maintained a coexistence system with Seonghwangsa(城隍祠) within the Eupseong. A Pungsu(風水) stream in a V-shape ran before the southern gate of Eupseong, forming a Sugu(水口) in front of Namsan(南山) that was an Ansan(案山). They dug a southern pond called Hongmunje(紅門堤) to protect the vitality of the village and built Gwanpungjeong(觀豊亭). In the 19th century, Hongmunje and Gwanpungjeong were renamed into Muheungje(茂興堤) and Muheungdang(茂興堂), respectively. Eupsu(邑藪) were planted in front of the southern pond including Wondo(圓島), and Songdeokbi(頌德碑), Dangsanmok(堂山木), and Dangsanseok(堂山石) served as a Sugumagi(水口막이) and protected the entrance of Eupchi. After the Liberation, the southern pond was buried in 1955, and a market was formed at the site, which resulted in the disappearance of its prototype. The study also investigated the name and location of Chilgeori(七거리) in the village as it was lost following the unification of Bu(府), Gun(郡), and Myeon(面) titles in 1914 during the Japanese colonial period. Chilgeori Dangsan was based on Yin and Yang theory and became the subject of the organization mainly composed of Grandfather Dangsan menhir and Grandmother Dangsan tree. Chilgeori Dangsan was a religious place of the community to guard the village, serving as seven gateways to control access at the village boundary and it had a locational feature of protecting the inner mountain ranges of Eupchi.

• Korean Journal of Environment and Ecology
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• v.36 no.5
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• pp.481-495
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• 2022

This study was designed to identify the actual state of naturalized plants and invasive alien species that cause disturbances to the ecosystem, plants which are introduced after forest restoration, and explore the implications resulting from the project. Onsite examination included 29 sites which have been subjected to forest restoration by the Korea Forest Service. Once these were chosen, activity took place twice a year in the spring (May-June) and in the summer (August-September) in 2020 and 2021. Areas not relevant to the project sites were excluded from this activity so that we could identify the plants that could be understood to have been introduced or brought into the site after the actual forest restoration. And the correlation was analyzed, between the naturalized flora within the project sites and the working types applied to the site through confirmation of completion of the restoration project. The naturalized plants appearing on the entire site cover a total of 109 taxa, which includes 29 families, 80 genera, 108 species and 1 subspecies, while invasive plants included 3 families, 7 genera and 8 species. The number of classifications and the naturalization rate gradually decreased over time, after the project. While there was no significant difference between the number of classification groups and the naturalization rate for naturalized plants between project sites, given the number of taxa of naturalized plants, organized by type of damage, there were relatively more naturalized plants that appeared in the severed section of the Baekdudaegan Mountain Range, as well as at quarry and facility sites. Seeding apparently results in naturalization rates as high as 15.545%, on average, based on comparisons of naturalization rates by sowing, seeding, planting, herb planting, and sod pitching channels, all of these being methods of vegetation for planting/greening of bareland and slopes within the project areas. With no seeding, it was 9.167%, higher than the average. As for other vegetation, there was no significant difference depending on application of the working type. This means that unlike the plants subjected to planting, the working type of seed planting which makes it difficult to identify whether a certain plant is a naturalized plant greatly affects the introduction of naturalized plants to the restoration sites, even when using herb planting and sod pitching to control plants and results. Therefore the study suggests that there be inspection by experts of seeds when sowing within restoration sites. The results of this study suggest good practices that will help to direct effective vegetation restoration and follow-up management.