• Title/Summary/Keyword: Variables

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The inference about the cause of death of Korean Fir in Mt. Halla through the analysis of spatial dying pattern - Proposing the possibility of excess soil moisture by climate changes - (한라산 구상나무 공간적 고사패턴 분석을 통한 고사원인 추정 - 기후변화에 따른 토양수분 과다 가능성 제안 -)

  • Ahn, Ung San;Kim, Dae Sin;Yun, Young Seok;Ko, Suk Hyung;Kim, Kwon Su;Cho, In Sook
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.21 no.1
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    • pp.1-28
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    • 2019
  • This study analyzed the density and mortality rate of Korean fir at 9 sites where individuals of Korean firs were marked into the live and dead trees with coordinates on orthorectified aerial images by digital photogrammetric system. As a result of the analysis, Korean fir in each site showed considerable heterogeneity in density and mortality rate depending on the location within site. This make it possible to assume that death of Korean fir can occur by specific factors that vary depending on the location. Based on the analyzed densities and mortality rates of Korea fir, we investigated the correlation between topographic factors such as altitude, terrain slope, drainage network, solar radiation, aspect and the death of Korean fir. The density of Korean fir increases with altitude, and the mortality rate also increases. A negative correlation is found between the terrain slope and the mortality rate, and the mortality rate is higher in the gentle slope where the drainage network is less developed. In addition, it is recognized that depending on the aspect, the mortality rate varies greatly, and the mean solar radiation is higher in live Korean fir-dominant area than in dead Korean fir-dominant area. Overall, the mortality rate of Korean fir in Mt. Halla area is relatively higher in areas with relatively low terrain slope and low solar radiation. Considering the results of previous studies that the terrain slope has a strong negative correlation with soil moisture and the relationship between solar radiation and evaporation, these results lead us to infer that excess soil moisture is the cause of Korean fir mortality. These inferences are supported by a series of climate change phenomena such as precipitation increase, evaporation decrease, and reduced sunshine duration in the Korean peninsula including Jeju Island, increase in mortality rate along with increased precipitation according to the elevation of Mt. Halla and the vegetation change in the mountain. It is expected that the spatial patterns in the density and mortality rate of Korean fir, which are controlled by topography such as altitude, slope, aspect, solar radiation, drainage network, can be used as spatial variables in future numerical modeling studies on the death or decline of Korean fir. In addition, the method of forest distribution survey using the orthorectified aerial images can be widely used as a numerical monitoring technique in long - term vegetation change research.

Influencing Factors Analysis for the Number of Participants in Public Contracts Using Big Data (빅데이터를 활용한 공공계약의 입찰참가자수 영향요인 분석)

  • Choi, Tae-Hong;Lee, Kyung-Hee;Cho, Wan-Sup
    • The Journal of Bigdata
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    • v.3 no.2
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    • pp.87-99
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    • 2018
  • This study analyze the factors affecting the number of bidders in public contracts by collecting contract data such as purchase of goods, service and facility construction through KONEPS among various forms of public contracts. The reason why the number of bidders is important in public contracts is that it can be a minimum criterion for judging whether to enter into a rational contract through fair competition and is closely related to the budget reduction of the ordering organization or the profitability of the bidders. The purpose of this study is to analyze the factors that determine the participation of bidders in public contracts and to present the problems and policy implications of bidders' participation in public contracts. This research distinguishes the existing sampling based research by analyzing and analyzing many contracts such as purchasing, service and facility construction of 4.35 million items in which 50,000 public institutions have been placed as national markets and 300,000 individual companies and corporations participated. As a research model, the number of announcement days, budget amount, contract method and winning bid is used as independent variables and the number of bidders is used as a dependent variable. Big data and multidimensional analysis techniques are used for survey analysis. The conclusions are as follows: First, the larger the budget amount of public works projects, the smaller the number of participants. Second, in the contract method, restricted competition has more participants than general competition. Third, the duration of bidding notice did not significantly affect the number of bidders. Fourth, in the winning bid method, the qualification examination bidding system has more bidders than the lowest bidding system.

Spatio-temporal Distribution of Macrozoobenthos in the Three Estuaries of South Korea (우리나라 3개 하구역 대형저서동물 군집 시공간 분포)

  • LIM, HYUN-SIG;LEE, JIN-YOUNG;LEE, JUNG-HO;SHIN, HYUN-CHUL;RYU, JONGSEONG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.24 no.1
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    • pp.106-127
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    • 2019
  • This study aims to understand spatio-temporal variations of macrozoobenthos community in Han River (HRE), Geum River (GRE), and Nakdong River estuaries (NRE) of Korea, sampled by National Survey of Marine Ecosystem. The survey was seasonally performed at a total of 20 stations for three years (2015-2017). Sediment samples were taken three times with van Veen grab of $0.1m^2$) areal size and sieved through a 1 mm pore size mesh on site. A total of 1,008 species were identified with 602 species in HRE, 612 in GRE, and 619 in NRE, showing similar number of species between estuaries. Mean density was $1,357ind./m^2$, showing the high in NRE ($1,357ind./m^2$), mid in GRE ($1,357ind./m^2$), and low in HRE ($1,127ind./m^2$). Mean biomass was $116.8g/m^2$, showing similar variations to density ($174.2g/m^2$ in NRE, $129.0g/m^2$ in GRE, $49.0g/m^2$ in HRE). Polychaeta dominated in number of species and density in three estuaries. Biomass-dominated taxon was Mollusca in HRE and GRE, and Echinodermata in NRE. Polychaetous species dominated all three estuaries over 4% of density, such as Dispio oculata, Heteromastus filiformis and Aonides oxycephala in HRE, Heteromastus filiformis and Scoletoma longifolia in GRE, and Pseudopolydora sp. and Aphelochaeta sp. in NRE, showing various density between estuaries. Community structure was determined by various environmental variables among estuaries such as mean grain size and sorting (HRE), salinity and mean grain size (GRE), and salinity, dissolved oxygen, loss on ignition and mud content (NRE). Our study demonstrates the application of different measures to manage ecosystems in three estuaries. HRE needs to alleviate sedimentary stressors such as sand mining, land-filling, dike construction. Management of GRE should be focused on fresh water control and sedimentary stressors. In NRE, monitoring of dominant benthos and process study on hypoxia occurrence in inner Masan Bay are necessary.

Effects of Balance Taping Therapy on Improving Knee Pain and the Obstacle in Daily Activity in Rural Elderly Women (밸런스 테이핑요법이 농촌 여성노인의 무릎통증과 일상활동장애 개선에 미치는 영향)

  • Kim, Ae-Jung;Park, Hae-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.218-227
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    • 2019
  • This study examined the effects of balance taping therapy on improving knee pain and the obstacles to daily activity in rural elderly women. The research design was a quasi-experimental research using a non-equivalent control group pre-test and post-test design. The data were collected from January 19th to April 14th, 2017. The research subjects included female elderly over 65 years old who visited 12 senior centers located at Y city in rural areas. The participants were composed of 26 people in the experimental group and 28 people in the control group. Data were collected before and 24 hours after balance taping therapy, and the pain and obstacles to daily activity were measured. The collected data were analyzed using the PASW Statistics 23 Program, which included a $X^2-test$, Shapiro-Wilk test, and Mann-Whitney U test. After the intervention, significant differences were observed in the knee pain (Z=-6.658, p<.001) and obstacles to daily activity (Z=-3.466, p=.001). With regard to lower domain variables of the obstacles to daily activity, significant differences in standing up (Z=-2.860, p=.004), daily activity (Z=-2.629, p=.009), walking (Z=-3.868, p<.001), and dressing up (Z=-2.049, p=.040) were observed between the two groups. On the other hand, there were no significant differences in grip (Z=-.542, p=.588) and arm stretching (Z=-.416, p=.678). In conclusion, applying balance taping to rural elderly women clearly decreases the level of knee pain, reduces the obstacles to daily activity, and improves their quality of life.

Verification the Systems Thinking Factor Structure and Comparison of Systems Thinking Based on Preferred Subjects about Elementary School Students' (초등학생의 시스템 사고 요인 구조 검증과 선호 과목에 따른 시스템 사고 비교)

  • Lee, Hyonyong;Jeon, Jaedon;Lee, Hyundong
    • Journal of The Korean Association For Science Education
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    • v.39 no.2
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    • pp.161-171
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    • 2019
  • The purposes of this study are: 1) to verify the systems thinking factor structure of elementary school students and 2) to compare systems thinking according to their preferred subjects in order to get implications for following research. For the study, pre-tests analyze data from 732 elementary school students using the STMI (Systems Thinking Measuring Instrument) developed by Lee et al. (2013). And exploratory factor analysis was conducted to identify the factor structure of the students. Based on the results of the pre-test, the expert group council revised the STMI so that elementary school students could respond to the 5-factor structure that STMI intended. In the post-test, 503 data were analyzed by modified STMI and exploratory factor analysis was performed. The results of the study are as follows: First, in the pre-test, elementary school students responded to the STMI with a test paper consisting of two factors (personal internal factors and personal external factors). The total reliability of the instrument was .932 and the reliability of each factor was analyzed as .857 and .894. Second, for modified STMI, elementary school students responded a 4-factor instrument. Team learning, Shared Vision, and Personal Mastery were derived independent factors, and mental model and systems analysis were derived 1-factor. The total reliability of the instrument was .886 and the reliability of each factor was analyzed as .686 to .864. Finally, a comparison of systems thinking according to preferred subjects showed a significant difference between students who selected science (engineering) group and art (music and physical education). In conclusion, it was confirmed that statistically meaningful results could be obtained using STMI modified by term and sentence structure appropriate for elementary school students, and it is a necessary to study the relation of systems thinking with various student variables such as the preferred subjects.

A Study for establishment of soil moisture station in mountain terrain (1): the representative analysis of soil moisture for construction of Cosmic-ray verification system (산악 지형에서의 토양수분 관측소 구축을 위한 연구(1): Cosmic-ray 검증시스템 구축을 위한 토양수분량 대표성 분석 연구)

  • Kim, Kiyoung;Jung, Sungwon;Lee, Yeongil
    • Journal of Korea Water Resources Association
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    • v.52 no.1
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    • pp.51-60
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    • 2019
  • The major purpose of this study is to construct an in-situ soil moisture verification network employing Frequency Domain Reflectometry (FDR) sensors for Cosmic-ray soil moisture observation system operation as well as long-term field-scale soil moisture monitoring. The test bed of Cosmic-ray and FDR verification network system was established at the Sulma Catchment, in connection with the existing instrumentations for integrated data provision of various hydrologic variables. This test bed includes one Cosmic-ray Neutron Probe (CRNP) and ten FDR stations with four different measurement depths (10 cm, 20 cm, 30 cm, and 40 cm) at each station, and has been operating since July 2018. Furthermore, to assess the reliability of the in-situ verification network, the volumetric water content data measured by FDR sensors were compared to those calculated through the core sampling method. The evaluation results of FDR sensors- measured soil moisture against sampling method during the study period indicated a reasonable agreement, with average values of $bias=-0.03m^3/m^3$ and RMSE $0.03m^3/m^3$, revealing that this FDR network is adequate to provide long-term reliable field-scale soil moisture monitoring at Sulmacheon basin. In addition, soil moisture time series observed at all FDR stations during the study period generally respond well to the rainfall events; and at some locations, the characteristics of rainfall water intercepted by canopy were also identified. The Temporal Stability Analysis (TSA) was performed for all FDR stations located within the CRNP footprint at each measurement depth to determine the representative locations for field-average soil moisture at different soil profiles of the verification network. The TSA results showed that superior performances were obtained at FDR 5 for 10 cm depth, FDR 8 for 20 cm depth, FDR2 for 30 cm depth, and FDR1 for 40 cm depth, respectively; demonstrating that those aforementioned stations can be regarded as temporal stable locations to represent field mean soil moisture measurements at their corresponding measurement depths. Although the limit on study duration has been presented, the analysis results of this study can provide useful knowledge on soil moisture variability and stability at the test bed, as well as supporting the utilization of the Cosmic-ray observation system for long-term field-scale soil moisture monitoring.

An Empirical Study on Classification, Business Type, Organizational Culture on Performance of Korean IT SMEs·Venture (중소·벤처기업의 업종, 영업형태, 조직문화가 기업성과에 미치는 영향에 관한 연구: 삼원분산분석(3-way ANOVA)을 중심으로)

  • Roh, Doo-Hwan;Hwang, Kyung-Ho
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.2
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    • pp.221-233
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    • 2019
  • In Korea, small and medium sized domestic enterprises(SMEs) play an pivotal role in the national economy, accounting for 99.9% of all enterprises, 87.9% of total employment, and 48.3% of production. and SMEs was driving a real force of the development of national economy in many respects such as innovation, job creation, industrial diversity, balanced regional development. Despite their crucial role in the national development, most of SMEs suffer from a lack of R&D capabilities and equipments as well as funding capacity. Public R&D institutes can provide SMEs with valuable supplementary technological knowledge and help them build technological capacity. so, In order to effectively support SMEs, government and public R&D institutes must be a priority to know about the factors influencing the performance related to technology transfer and technological collaborations. In particular, SMEs are not only taking up a large portion of the national economy, but also their influence in politics and economy so strong that raising the competitiveness of small and medium-sized companies is a national policy goal that must be achieved in order to achieve sustained economic growth. For this reason, it is necessary to look specifically at the relationship between concepts such as the environment, strategy, and organizational culture surrounding the enterprise to enhance the competitiveness of SMEs. The paper analyzes 665 companies to find out which organizational culture affects their performance by classification and type of business of SMEs. This study demonstrated that when SMEs seek consistency in their external environment, strategies, and organizational structure to maintain their continued competitiveness. According to three-way analysis of variance (3-way ANOVA) indicates that classification of industries in SMEs has statistically significant main effects, but the type of business and organizational culture do not have significant effects. However, the company's organizational performance (operating profit) of SMES were found to differ significantly in comparison between groups according to classification standards of industries, and therefore adopted some parts. In addition, an analysis of the effect of interaction between the three independent variables of small and medium-sized enterprises has shown that there are statistically significant interaction effects among classification, types of business, and organizational cultures. The results shows that there is an organizational culture suitable for each industry classification and type of business of an entity, and is expected to be used as a basis for establishing promotion policies related to the incubation and commerciality of small and medium-sized venture companies in the future.

Quality Characteristics of Dough and Bread Added With Extruded Chestnut Shell Powder Under Various Conditions (압출성형 공정변수에 따른 율피분말 첨가 반죽의 물성과 식빵의 품질특성)

  • Lee, Jeong Sug;Yoon, Seong Jun;Ryu, Gi-Hyung
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.351-359
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    • 2017
  • This study investigates the quality characteristics of dough and bread added with 6% chestnut shell powder and extruded chestnut shell powder at various conditions. As extrusion process variables, melt temperature ($110^{\circ}C$, $130^{\circ}C$, $150^{\circ}C$) and moisture (25% and 30%) were controlled. Total dietary fiber content was slightly increased in extruded chestnut shell powder group. In the farinogram, absorption was significantly increased in the group of 25% moisture content and 30% moisture content (p<0.05). After 2 hours and 3 hours, the leavening heights of dough for control showed a similar tendency to that of dough with extruded chestnut shell at a melt temperature $150^{\circ}C$ and with moisture content of 25% and 30%. Specific volume was the highest at a control of $3.74{\pm}0.08cc/g$ and extruded chestnut shell powder group was slightly higher than the chestnut shell powder group. Firmness after 1 day on control of $107.42{\pm}14.52g$ was similar to that of the bread with extruded chestnut shell at a temperature of $150^{\circ}C$ and moisture content of 25% for $113.33{\pm}6.17g$. In conclusion, the extrusion-cooking of chestnut shell powder improved the quality characteristics of dough and bread. The optimum combinations of conditions in tested range were melt temperature at $150^{\circ}C$ and moisture content at 25%, and melt temperature at $130^{\circ}C$ and moisture content at 30%.

The Differences in Obesity Rates According to Status of Co-Residence with Their Parents in Korean Adolescents: The Implication of the Gender of Single Parent Living with Adolescents (한국 청소년에서 부모와의 동거 형태에 따른 비만율 차이: 동거 부모 성별의 영향)

  • Kim, Nahee;Cho, Young Gyu;Kang, Jae-Heon;Park, Hyun Ah;Kim, Kyoungwoo;Hur, Yang-Im;Kwon, Duho
    • Korean journal of health promotion
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    • v.18 no.4
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    • pp.177-183
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    • 2018
  • Background: Many studies have reported that adolescents living with single parent have a high risk of obesity. However, those studies did not explore the implication of the gender of single parent living with adolescents. This study investigated the differences in obesity rates according to status of co-residence with their parents in Korean adolescents. The family living with single parent was classified into the family living with single father and the family living with single mother. Methods: This cross-sectional study involved 59,602 adolescents who participated in the 2017 Korea Youth Risk Behavior Web-based Survey. The data on height, weight, status of co-residence with parents, and the other variables were obtained through online questionnaires. Results: In male adolescents, the family living with single mother was related to a high proportion of obesity (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.09-1.40) and overweight (OR 1.17, 95% CI 1.03-1.34). However, in female adolescents, the family living with single father was related to a high proportion of obesity (OR 1.49, 95% CI 1.23-1.82). In addition, female adolescents living with neither parent were more likely to be obese (OR 1.47, 95% CI 1.13-1.91) and overweight (OR 1.31, 95% CI 1.00-1.70). Conclusions: This study showed a risk of obesity in adolescents living with single parent differs according to the gender of single parent living with adolescents. Not adolescents living with a same-gender parent, but those living with an opposite-gender parent have a high risk of obesity.

The Effect of Influencer's Characteristics and Contnets Quality on Brand Attitude and Purchase Intention: Trust and Self-congruity as a Mediator (소셜미디어 인플루언서의 개인특성과 콘텐츠 특성이 브랜드 태도와 구매의도에 미치는 영향: 신뢰와 자아일치성을 매개로)

  • Lee, Myung Jin;Lee, Sang Won
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.5
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    • pp.159-175
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    • 2021
  • This study attempted to analyze the relationship between influencer's characteristic factors such as professionalism, authenticity, and interactivity and content quality factors consisting of accuracy, completeness, and diversity on brand attitude and purchase attitude through trust and self-consistency. To reveal the structural relationship between main variables, a survey was conducted on 201 users. An EFA, CFA, and reliability analysis were performed to confirm reliability and validity. And structural equation was conducted to verify hypothesis. The main results are as follows. First, it was found that professionalism and interactivity had a significant positive effect on trust. And, accuracy, completeness, and variety were all found to have a significant positive effect on trust. Second, in the relationship between individual characteristic factors and self-consistency, it was found that professionalism and authenticity had a significant positive effect on self-consistency. In addition, in the relationship between content quality and self-consistency, accuracy, completeness, and diversity were found to have a positive effect on self-consistency along with trust. Third, in the relationship between trust and self-consistency on brand attitude and purchase intention, both trust and self-consistency were found to have a statistically significant positive effect on brand attitude. It was found that only self-consistency and brand attitude had a statistically significant positive effect on purchase intention. These findings showed that when users perceive professionalism and interaction with influencer, trust increases, and professionalism and progress increase self-consistency with influencer. In addition, in the case of content quality, it was found that trust and self-consistency responded positively when perceived content quality through content accuracy, completeness, and diversity. Also, trust and self-consistency increased attitudes toward brands and could influence consumption behavior such as purchase intention. Therefore, for effective marketing performance using influencer's influence in the field of influencer marketing, which has a strong information delivery on products and brands, not only personal characteristics such as professionalism, authenticity, and interactivity, but also quality of content should be considered. The above research results are expected to suggest implications for marketing strategies and practices as one available basic data to exert the expected effect of marketing using influencer.