• Title/Summary/Keyword: 과학과 기술

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A History of Termite Control and Improvements to Prevent Termites in Wooden Architectural Heritage (국내외 흰개미 방제 기술의 발달 과정과 목조건축문화재의 흰개미 피해 저감을 위한 방안)

  • LEE, Sangbin;IM, Ikgyun;KIM, Sihyun
    • Korean Journal of Heritage: History & Science
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    • v.54 no.2
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    • pp.194-215
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    • 2021
  • Termites are important decomposers in the ecosystem. They are also economically significant structural pests. In this study, we reviewed the developments of termite control and recent research on termite management to provide information on the prevention and control of termites. In Korea, most of the damage to wooden historical buildings is caused by subterranean termites. Reticulitermes speratus kyushuensis is the main species, which is widely found throughout the country. In the early 1900s, inorganic insecticides, such as arsenic dust, were used for termite control. After the synthesis of chlorinated hydrocarbon pesticide in the 1940s, it was widely utilized and demonstrated high termite control efficacy. However, chlorinated hydrocarbon insecticides were later banned, disappearing from markets after reports emerged concerning environmental contamination and toxicity to humans. Therefore, the termite control industry sought a new termiticide; hence many pesticides were utilized for termite control. Organophosphate (1960s), carbamate (1970s), pyrethroid, and insect growth inhibitor (1980s) were newly synthesized and adopted. In the 1990s, the first commercial baits using chitin synthesis inhibitors (CSI) were developed, providing a means to eliminate an entire colony of subterranean termites around a structure. Many studies have been carried out on soil termiticides (liquid termiticides) and CSI baits to increase their efficacy, and different baits such as aboveground bait stations, fluid bait, and high-durability bait were also developed in the 2000s. In addition, the paradigm of termite control has shifted from localized treatments using soil termiticides to area-wide pest management using CSI baits to create termite-free zones and protect buildings over time. Termite infestations in wooden historical buildings in Korea have been reported since 1980, and considerable attention was drawn in the 1990s when several UNESCO world heritages such as the Jongmyo Shrine and the Janggyeong Panjeon Depositories of Haeinsa Temple were infested by subterranean termites. Since then, a survey of termite infestation in wooden architectural heritage has been conducted, and the National Research Institute of Cultural Heritage and Heritage Care Program regularly monitors those properties. Finally, we suggest termite management using primarily CSI baits, selective application of various soil treatments applied to the object, foundation soil treatment, research and development of durable termite baits, application of area-wide programs for wooden-building complexes, application of integrated termite management (ITM), and regular education for owners and managers to prevent and reduce termite damage.

Long-term and Short-term Reciprocity in Parent-Child Relations for Korean Sons and Daughter (세대 간 지원교환의 장기적·단기적 호혜성: 아들과 딸의 비교)

  • Choi, Heejin;Han, Gyoung-hae
    • 한국노년학
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    • v.37 no.1
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    • pp.83-102
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    • 2017
  • Expending on a life course perspective, this study explores the long-term and short-term reciprocity in parent-child relationships in Korean context. Since the reasons for providing filial support are believed to differ by gender, we focused on how a child's gender affects both types of reciprocity. Data were collected from middle-aged sons (N=726) and daughters (N=883) with at least one surviving parent. Logistic regression was then conducted in order to examine the relations between the support a child currently provides to parents and the current or previous support received from the parents. Dependent variables are financial and instrumental support that middle-aged child currently provide to the parents. The financial and instrumental support a child received from the parents within a year are included in the model as an independent variable to assess short-term reciprocity. The level of financial support a child has received during the transition to adulthood process is included in the model as a independent variable to explore long-term reciprocity. Result supports the existence of gender differences in the long-term reciprocity. Daughters provided instrumental support in response to the financial support that they had received from parents during the transition to adulthood process. However, for sons, this tendency was not found. When it comes to financial support, long-term reciprocity was observed neither for the sons nor for the daughters. Both sons and daughters are prone to provide financial support to the aged parents regardless of the level of financial support they had received during the transition to adulthood process. Short-term reciprocity was found both in sons and daughters. when they have been receiving a financial or an instrumental support from the aged parents within a year, they tend to provided instrumental support to the parents. This study shows that the aged parents still fulfill the reciprocal relationship to a certain degree. Secondly, we can conclude that the norm of reciprocity interplays with the norm of filial responsibility in contemporary Korea.

Design and Implementation of a Similarity based Plant Disease Image Retrieval using Combined Descriptors and Inverse Proportion of Image Volumes (Descriptor 조합 및 동일 병명 이미지 수량 역비율 가중치를 적용한 유사도 기반 작물 질병 검색 기술 설계 및 구현)

  • Lim, Hye Jin;Jeong, Da Woon;Yoo, Seong Joon;Gu, Yeong Hyeon;Park, Jong Han
    • The Journal of Korean Institute of Next Generation Computing
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    • v.14 no.6
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    • pp.30-43
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    • 2018
  • Many studies have been carried out to retrieve images using colors, shapes, and textures which are characteristic of images. In addition, there is also progress in research related to the disease images of the crop. In this paper, to be a help to identify the disease occurred in crops grown in the agricultural field, we propose a similarity-based crop disease search system using the diseases image of horticulture crops. The proposed system improves the similarity retrieval performance compared to existing ones through the combination descriptor without using a single descriptor and applied the weight based calculation method to provide users with highly readable similarity search results. In this paper, a total of 13 Descriptors were used in combination. We used to retrieval of disease of six crops using a combination Descriptor, and a combination Descriptor with the highest average accuracy for each crop was selected as a combination Descriptor for the crop. The retrieved result were expressed as a percentage using the calculation method based on the ratio of disease names, and calculation method based on the weight. The calculation method based on the ratio of disease name has a problem in that number of images used in the query image and similarity search was output in a first order. To solve this problem, we used a calculation method based on weight. We applied the test image of each disease name to each of the two calculation methods to measure the classification performance of the retrieval results. We compared averages of retrieval performance for two calculation method for each crop. In cases of red pepper and apple, the performance of the calculation method based on the ratio of disease names was about 11.89% on average higher than that of the calculation method based on weight, respectively. In cases of chrysanthemum, strawberry, pear, and grape, the performance of the calculation method based on the weight was about 20.34% on average higher than that of the calculation method based on the ratio of disease names, respectively. In addition, the system proposed in this paper, UI/UX was configured conveniently via the feedback of actual users. Each system screen has a title and a description of the screen at the top, and was configured to display a user to conveniently view the information on the disease. The information of the disease searched based on the calculation method proposed above displays images and disease names of similar diseases. The system's environment is implemented for use with a web browser based on a pc environment and a web browser based on a mobile device environment.

A Study on The practice method of Do(道) of The I'Ching(周易) (주역(周易)의 도(道)의 실천방법(實踐方法)에 관한 연구)

  • Lee, Kyu-Hee
    • (The)Study of the Eastern Classic
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    • no.57
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    • pp.231-262
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    • 2014
  • Seeing so many people who use trickery and schemes become successful these days, a lot of people are concerned that the ethical values of our society are breaking down. The saint who created I'Ching presents ways to see through the characteristics of people and ethical values, claims that carrying out these values in everyday life while being aware of misfortunes can lessen our faults or make them disappear, and presents ways to conduct moral actions to people with the hopes of walking down the right road. The Do in Dodeok, which means "ethics" in Korean, stands for "body." Until now, there has been a lack of research on the do in I'Ching. Therefore, the goal of this study was to research the idea and specific actions of Do implied in Gyeomun and Shibik of I'Ching, to aid application of abstract Do to fit the different situations of people. In the beginning, Do was not categorized. It was heavens Do if it was in the heavens, earth Do if it was on the earth, and human Do if it referred to people. I'Ching presents various different ideas of Do to apply natural Do to people. The researcher divided Do largely into heavens Do, earth Do, human Do, heavens, earth and human Do, middle Do and changing Do, and aimed to present various examples of application of Do including Do of a man, Do of heaven and earth, Do of heavens and gods, orders of the heavens, Do of a woman, Do of a family, Do of a saint, Do of a great person, Do of a noble man, Do of a child, Do of a household, Do of the heavens, earth and people, good fortune of men, and wrong Do and frugal Do, to show how and when Do is used and aid in execution of Do through I'Ching. The practice principle of Do according to I'Ching is for people to understand the various types of Do presented by I'Ching, and help all people become saints and noble men by conducting Do at the right time and place. If people make an effort to keep the principle of Do presented in I'Ching, all trickery and schemer will disappear and a society of great unity will be created, where all members are happy.

A Case Study on Introducing Vita Parcours as Forest Leisure Sports Facility in Saneum Healing Forest (산음 치유의 숲 Vita Parcours 도입 사례 연구 - Vita Parcours 도입을 사례로 -)

  • Lee, Jin-Kyu;Kim, Ki Weon
    • The Journal of the Korean Institute of Forest Recreation
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    • v.22 no.4
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    • pp.71-81
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    • 2018
  • It is necessary to build a quality-enhancing forest leisure sports facility according to values that value life quality, national forest policy. Vita Parcours (fitness trails) is found to be the activities highly convenient, so their introduction and promotion in Korea should be highly considered. field survey was necessary to explore the possibility of installing Vita Parcours. Several sites were selected, such as Asean recreational forest, Unaksan recreational forest, Yumyeongsan recreational forest, Saneum recreational forest, Jungmisan recreational forest and National center for forest therapy. At these locations, we explored the current status of forest facilities and forest trails. A total number of 31 exercise facilities has been identified and surveyed, some of which are located on the trails (2), alongside the trail (9), alongside trail boundaries (2) or represent facilities suitable for both outdoor and indoor exercise within the forest (18), all of whom provide location for 44 different exercise routines (flexibility exercises (23), endurance (12) and strength exercises (9)). Field work also included identification of forests paths, the total number of whom was 34 paths - 30 identified as trails, 2 as hiking trails, 1 as a forest path for relaxation and healing and 1 as an exploratory path. Regarding the structure and shape of these trails, 32 was straight in shape and only 2 designed as a circular forest trails. Average length of these trails was 652.2m with the highest and the lowest point altitude difference of 60m, on average. Saneum recreational forest provide the most suitable site/environment for Vita Parcours and as a result of this, Saneum recreational forest is proposed as a location to support the endeavors in promotion of these valuable forest fitness trails. Among the forest paths at this site, a forest path which has a length of 1.84km and 73.0m the highest and the lowest point altitude difference was selected as the most suitable, and may be equipped with necessary stations for exercise or obstacles. In addition, if these trails are to be introduced and welcomed by its users, we must assure that they are properly maintained.

Application of diversity of recommender system accordingtouserpreferencechange (사용자 선호도 변화에 따른 추천시스템의 다양성 적용)

  • Na, Hyeyeon;Nam, Kihwan
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.67-86
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    • 2020
  • Recommender Systems have been huge influence users and business more and more. Recently the importance of E-commerce has been reached rapid growth greatly in world-wide COVID-19 pandemic. Recommender system is the center of E-commerce lively. Top ranked E-commerce managers mentioned that recommender systems have a major influence on customer's purchase such as about 50% of Netflix, Amazon sales from their recommender systems. Most algorithms have been focused on improving accuracy of recommender system regardless of novelty, diversity, serendipity etc. Recommender systems with only high accuracy cannot satisfy business long-term profit because of generating sales polarization. In addition, customers do not experience enjoyment of shopping from only focusing accuracy recommender system because customer's preference is changed constantly. Therefore, recommender systems with various values need to be developed for user's high satisfaction. Reranking is the most useful methodology to realize diversity of recommender system. In this paper, diversity of recommender system is represented through constructing high similarity with users who have different preference using each user's purchased item's category algorithm. It is distinguished from past research approach which is changing the algorithm of recommender system without user's diversity preference level. We tried to discover user's diversity preference level and observed the results how the effect was different according to user's diversity preference level. In addition, graph-based recommender system was used to show diversity through user's network, not collaborative filtering. In this paper, Amazon Grocery and Gourmet Food data was used because the low-involvement product, such as habitual product, foods, low-priced goods etc., had high probability to show customer's diversity. First, a bipartite graph with users and items simultaneously is constructed to make graph-based recommender system. However, each users and items unipartite graph also need to be established to show diversity of recommender system. The weight of each unipartite graph has played crucial role changing Jaccard Distance of item's category. We can observe two important results from the user's unipartite network. First, the user's diversity preference level is observed from the network and second, dissimilar users can be discovered in the user's network. Through the research process, diversity of recommender system is presented highly with small accuracy loss and optimalization for higher accuracy is possible controlling diversity ratio. This paper has three important theoretical points. First, this research expands recommender system research for user's satisfaction with various values. Second, the graph-based recommender system is developed newly. Third, the evaluation indicator of diversity is made for diversity. In addition, recommender systems are useful for corporate profit practically and this paper has contribution on business closely. Above all, business long-term profit can be improved using recommender system with diversity and the recommender system can provide right service according to user's diversity level. Lastly, the corporate selling low-involvement products have great effect based on the results.

Job Characteristics and Status of Community Occupational Therapist : Focus on OTs in Public Health Centers (지역사회 작업치료사의 업무 특성 및 실태 조사 : 보건소 근무 작업치료사를 중심으로)

  • Min, Kyoung-chul;Kim, Eun-hee;Woo, Hee-soon
    • The Journal of Korean society of community based occupational therapy
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    • v.10 no.3
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    • pp.37-52
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    • 2020
  • Objective : This study was conducted to identify occupational therapists working in public health centers, the characteristics and actual conditions of occupational therapists in the community, and use them as basic data on occupational therapists in the community as of 2020. Methods : 77 questionnaires were replied by e-mail from OTs work at nationwide health public centers. Job characteristics and status were analysed by descriptive statistics and check correlation between job satisfaction and other factors. Results : Most survey respondents were female(77.9%) and 20-30(96.1%).. Some occupational therapists worked for dementia related team(72.7%) and others worked for like visiting care, health care, and rehabilitation center etc. Rate of experiences of public health center was 1-2 years(67.5%), the most common type of contract was flexible part-time worker(61%) and work intensity(94.8%) and satisfaction of work was very high(85.7%). The highest difficulty of their job was budget administrative work(26.7%) and of non-work difficulty was inequality under contracts(27.2%). They usually participated at dementia shelter, visiting OT, group OT. Difficulty of their job was high in budget administration, dementia shelters, and visiting work treatments. Goals of treatment were high in improvement of cognitive ability and, family support. Frequency of treatment was high in improvement of cognitive therapy, family support, and evaluation. Occupational therapy targets for health centers were dementia, the general elderly, and adult brain lesions, including those for ordinary people, psychiatric disorders and children. It was found that the primary occupations for evaluation were nurses (35.7%) and occupational therapists (33.7%), and that MMSE-DS, SGDS, and SMCQ were used a lot. Conclusion : This study could identify the job characteristics and status of community OTs. We hope that this result could be basic data for building expertise and role for community OTs in changing situations like community cares.

Changes in Landscape Characteristics of Stream Habitats with the Construction and Operation of River-Crossing Structures in the Geum-gang River, South Korea (금강에서 횡단구조물의 설치와 운영에 따른 하천 서식처의 경관 특성 변화)

  • Kim, Dana;Lee, Cheolho;Kim, Hwirae;Ock, Giyoung;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.8 no.1
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    • pp.64-78
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    • 2021
  • This study was conducted to find out the effect of the construction and operation of river-crossing structures on the habitat landscape characteristics in the Geum-gang River, South Korea. A total of three study reaches were selected in the downstream of the Daecheong Dam: the Buyong-ri reach, which is a control that is not affected by the construction and operation of the weir of the Four Rivers Project and Sejong-bo Weir reach and Gongju-bo Weir reach of the upper and lower sections of each weir that are affected by the weir construction and operation. The habitat type was classified, and then the structural characteristics of the landscape were analyzed using aerial photographs taken before and after the construction of the Daecheong Dam, before and after the construction of the weir, and before and after the weir gate operation. After the construction of Daecheong Dam in Geum River, the area of the bare land greatly decreased, and the area of grassland and woodland increased in the downstream of the dam. In addition, the patch number in the river landscape increased, the patch size decreased, and the landscape shape index and the habitat diversity increased. Therefore, after the construction of the dam, the bare land habitat was changed to a vegetated habitat, and the habitat was fragmented and diversified in the downstream of the dam. After the construction of the weirs, the area of open water increased by 18% in the Sejong-bo reach and by 90% in the Gongju-bo reach, and the landscape shape index of the open water decreased by 32% in the Sejong-bo reach and by 35% in the Gongju-bo reach, and the habitat diversity index decreased to 25% in the Sejong-bo reach and to 24% in the Gongju-bo reach. Therefore, the open water habitat was expanded, the shape of the habitat was simplified, and the habitat diversity decreased according to the construction of the weirs. After water-gate opening of the weir, the bare land that disappeared after the construction of the weir reappeared, and the landscape shape index and habitat diversity index increased in both terrestrial and open water habitats. Therefore, it was found that the landscape characteristics of the river habitats were restored to the pre-construction of the weir by the operation of the weir gate. The effect of weir gate opening was delayed in the downstream than in the upstream of the weir. Although the characteristics of the landscape structure in the river habitat changed due to the construction of the river-crossing structures, it is thought that proper technology development for the ecological operation of the structures is necessary as the habitat environments can be restored by the operation of these structures.

The Dynamics of CO2 Budget in Gwangneung Deciduous Old-growth Forest: Lessons from the 15 years of Monitoring (광릉 낙엽활엽수 노령림의 CO2 수지 역학: 15년 관측으로부터의 교훈)

  • Yang, Hyunyoung;Kang, Minseok;Kim, Joon;Ryu, Daun;Kim, Su-Jin;Chun, Jung-Hwa;Lim, Jong-Hwan;Park, Chan Woo;Yun, Soon Jin
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.198-221
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    • 2021
  • After large-scale reforestation in the 1960s and 1970s, forests in Korea have gradually been aging. Net ecosystem CO2 exchange of old-growth forests is theoretically near zero; however, it can be a CO2 sink or source depending on the intervention of disturbance or management. In this study, we report the CO2 budget dynamics of the Gwangneung deciduous old-growth forest (GDK) in Korea and examined the following two questions: (1) is the preserved GDK indeed CO2 neutral as theoretically known? and (2) can we explain the dynamics of CO2 budget by the common mechanisms reported in the literature? To answer, we analyzed the 15-year long CO2 flux data measured by eddy covariance technique along with other biometeorological data at the KoFlux GDK site from 2006 to 2020. The results showed that (1) GDK switched back-and-forth between sink and source of CO2 but averaged to be a week CO2 source (and turning to a moderate CO2 source for the recent five years) and (2) the interannual variability of solar radiation, growing season length, and leaf area index showed a positive correlation with that of gross primary production (GPP) (R2=0.32~0.45); whereas the interannual variability of both air and surface temperature was not significantly correlated with that of ecosystem respiration (RE). Furthermore, the machine learning-based model trained using the dataset of early monitoring period (first 10 years) failed to reproduce the observed interannual variations of GPP and RE for the recent five years. Biomass data analysis suggests that carbon emissions from coarse woody debris may have contributed partly to the conversion to a moderate CO2 source. To properly understand and interpret the long-term CO2 budget dynamics of GDK, new framework of analysis and modeling based on complex systems science is needed. Also, it is important to maintain the flux monitoring and data quality along with the monitoring of coarse woody debris and disturbances.

An Exploration of MIS Quarterly Research Trends: Applying Topic Modeling and Keyword Network Analysis (MIS Quarterly 연구동향 탐색: 토픽모델링 및 키워드 네트워크 분석 활용)

  • Kang, Eunkyung;Jung, Yeonsik;Yang, Seonuk;Kwon, Jiyoon;Yang, Sung-Byung
    • Journal of Intelligence and Information Systems
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    • v.28 no.2
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    • pp.207-235
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    • 2022
  • In a knowledge-based society where knowledge and information industries are the main pillars of the economy, knowledge sharing and diffusion and its systematic management are recognized as essential strategies for improving national competitiveness and sustainable social development. In the field of Information Systems (IS) research, where the convergence of information technology and management takes place in various ways, the evolution of knowledge occurs only when researchers cooperate in turning old knowledge into new knowledge from the perspective of the scientific knowledge network. In particular, it is possible to derive new insights by identifying topics of interest in the relevant research field, applied methodologies, and research trends through network-based interdisciplinary graftings such as citations, co-authorships, and keywords. In previous studies, various attempts have been made to understand the structure of the knowledge system and the research trends of the relevant community by revealing the relationship between research topics, methodologies, and co-authors. However, most studies have compared two or more journals and been limited to a certain period; hence, there is a lack of research that looked at research trends covering the entire history of IS research. Therefore, this study was conducted in the following order for all the papers (from its first issue in 1977 to the first quarter of 2022) published in the MIS Quarterly (MISQ) Journal, which plays a leading role in revealing knowledge in the IS research field: (1) After extracting keywords, (2) classifying the extracted keywords into research topics, methodologies, and theories, and (3) using topic modeling and keyword network analysis in order to identify the changes from the beginning to the present of the IS research in a chronological manner. Through this study, it is expected that by examining the changes in IS research published in MISQ, the developing patterns of IS research can be revealed, and a new research direction can be presented to IS researchers, nurturing the sustainability of future research.