• Title/Summary/Keyword: statistical verification

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Climate Change Impact on Korean Forest and Forest Management Strategies (기후변화가 한국 산림에 미치는 영향과 관리 전략)

  • Kim, Moonil;Yoo, Somin;Kim, Nahui;Lee, Wona;Ham, Boyoung;Song, Cholho;Lee, Woo-Kyun
    • Korean Journal of Environmental Biology
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    • v.35 no.3
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    • pp.413-425
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    • 2017
  • This manuscript describes the relationship between climate change and forest growth, forest species, carbon stocks, and tree mortality. 1) In the aspect of forest growth, the growth of major coniferous species, including Pinus densiflora, had a negative correlation with temperature. On the other hand, major deciduous oak species, including Quercus variabilis and Quercus mongolica, had a positive correlation with temperature. 2) When considered in the aspect of the forest species distribution, various models commonly showed a decrease in the distribution of coniferous species and an increase in oak species due to climate change in the medium to long term. 3) From the carbon stock perspective, there was a difference in the estimation according to the status of forest management. Most of Korean forests will mature to become over-matured forest after year 2030 and are estimated to produce approximately 410 million ton forest biomass until 2090 with the current cutting regulations for sustainable forest management announced by the Korean Forest Service. 4) In the forest mortality, the mortality rate of the major coniferous species showed a clear tendency to increase higher temperatures while it decreased for the oak species with no verification of statistical significance. Moreover, the mortality of the subalpine coniferous species was projected to progress rapidly. considering the overall impacts described above, there should be a management strategy for coniferous species that are relatively vulnerable to climate change. Moreover, a sustainable forest plan in the aspect of ecosystem services, carbon sequestration and storage, which is linked to global issues such as Sustainable Development Goals, ecosystem services and negative emission.

Calculation of Surface Broadband Emissivity by Multiple Linear Regression Model (다중선형회귀모형에 의한 지표면 광대역 방출율 산출)

  • Jo, Eun-Su;Lee, Kyu-Tae;Jung, Hyun-Seok;Kim, Bu-Yo;Zo, Il-Sung
    • Journal of the Korean earth science society
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    • v.38 no.4
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    • pp.269-282
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    • 2017
  • In this study, the surface broadband emissivity ($3.0-14.0{\mu}m$) was calculated using the multiple linear regression model with narrow bands (channels 29, 30, and 31) emissivity data of the Moderate Resolution Imaging Spectroradiometer (MODIS) on Earth Observing System Terra satellite. The 307 types of spectral emissivity data (123 soil types, 32 vegetation types, 19 types of water bodies, 43 manmade materials, and 90 rock) with MODIS University of California Santa Barbara emissivity library and Advanced Spaceborne Thermal Emission & Reflection Radiometer spectral library were used as the spectral emissivity data for the derivation and verification of the multiple linear regression model. The derived determination coefficient ($R^2$) of multiple linear regression model had a high value of 0.95 (p<0.001) and the root mean square error between these model calculated and theoretical broadband emissivities was 0.0070. The surface broadband emissivity from our multiple linear regression model was comparable with that by Wang et al. (2005). The root mean square error between surface broadband emissivities calculated by models in this study and by Wang et al. (2005) during January was 0.0054 in Asia, Africa, and Oceania regions. The minimum and maximum differences of surface broadband emissivities between two model results were 0.0027 and 0.0067 respectively. The similar statistical results were also derived for August. The surface broadband emissivities by our multiple linear regression model could thus be acceptable. However, the various regression models according to different land covers need be applied for the more accurate calculation of the surface broadband emissivities.

Fog Detection over the Korean Peninsula Derived from Satellite Observations of Polar-orbit (MODIS) and Geostationary (GOES-9) (극궤도(MODIS) 및 정지궤도(GOES-9) 위성 관측을 이용한 한반도에서의 안개 탐지)

  • Yoo, Jung-Moon;Yun, Mi-Young;Jeong, Myeong-Jae;Ahn, Myoung-Hwan
    • Journal of the Korean earth science society
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    • v.27 no.4
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    • pp.450-463
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    • 2006
  • Seasonal threshold values for fog detection over the ten airport areas within the Korean Peninsula have been derived from the data of polar-orbit Aqua/Terra MODIS and geostationary GOES-9 during a two years. The values are obtained from reflectance at $0.65{\mu}m\;(R_{0.65})$ and the difference in brightness temperature between $3.7{\mu}m\;and\;11{\mu}m\;(T_{3.7-11})$. In order to examine the discrepancy between the threshold values of two kinds of satellites, the following four parameters have been analyzed under the condition of daytime/nighttime and fog/clear-sky, utilizing their simultaneous observations over the Seoul metropolitan area: brightness temperature at $3.7{\mu}m$, the temperature at $11{\mu}m,\;the\;T_{3.7-11}$ for day and night, and the $R_{0.65}$ for daytime. The parameters show significant correlations (r<0.5) in spatial distribution between the two kinds of satellites. The discrepancy between their infrared thresholds is mainly due to the disagreement in their spatial resolutions and spectral bands, particularly at $3.7{\mu}m$. Fog detection from GOES-9 over the nine airport areas except the Cheongju airport has revealed accuracy of 60% in the daytime and 70% in the nighttime, based on statistical verification. The accuracy decreases in foggy cases with twilight, precipitation, short persistence, or the higher cloud above fog. The sensitivity of radiance and reflectance with wavelength has been analyzed in numerical experiments with respect to various meteorological conditions to investigate optical characteristics of the three channels.

A Preliminary Study on Motor Ability of Preschool Aged Children by Using Bruininks-Oseretsky Test of Motor Proficiency-2 (BOT-2) Short Form (Bruininks-Oseretsky Test of Motor Proficiency-2(BOT-2) 단축형을 사용한 학령전기 아동의 운동능력에 대한 연구)

  • Hong, Ki-hoon;Kim, Do-yeon;Kang, Hye-bin;Park, Tae-yeong;Yun, Eun-jeong;Lee, Ji-yeong;Jung, Hye-rim
    • The Journal of Korean Academy of Sensory Integration
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    • v.14 no.1
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    • pp.31-40
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    • 2016
  • Objective : This study aimed to provide the preliminary data as a pilot study on standardizing BOT-2 by using an assessment criteria linked to Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) short form for the children with preschool years(4-6 year old) in South Korea. Methods : A total of 81 children aged 4-6 in Busan and Gimhae were participated in this study. They were evaluated by using BOT-2 SF. It provides the average values and standard deviations about the abilities of praxis along with descriptive statistical analyses, and has the verification of gender differences by using independent t-test and using ANOVA for discrepancies in the abilities of praxis. Results : There were significance difference in the total raw score between four and five (p=.000), the items on fine motor accuracy between five and six year olds (p=.014). Girls showed higher scores than boys in fine motor accuracy, fine motor integration and balance (p=.022, p=.006, p=.031). Also, mean raw scores of 4 and 5 year olds (p=.007, =.000), and the all age group's standard scores were higher than the age in American children who were the participants of BOT-2. Conclusion : This study suggested the average of each item with regard to the ability of motor praxis about the children of preschool ages and showed the dissimilarity in the ability of motor praxis between age and gender, also between the participants in this study and American children who were participants of BOT-2. The research could provide basic data for future studies to standardize BOT-2 SF for korean preschoolers.

The Influence of Education and Mentoring of Entrepreneurship on the Intentions of Business Start-Up - Focusing on Self-Efficacy and Resilience - (창업교육과 멘토링이 창업의지에 미치는 영향 - 자기효능감과 회복탄력성의 매개효과를 중심으로 -)

  • Kim, Young-tae
    • Journal of Venture Innovation
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    • v.3 no.1
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    • pp.1-26
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    • 2020
  • The purpose of this study is to explore the factors affecting rural experience by applying the unified push-pull-mooring model. The theoretical model is an unified PPM model that introduces new variables based on PPM. The pull factor of the newly introduced variables were reconstructed based on the Schmitt's Experience model and ServQual model. The hypothesis is set as follows. The push factor will have a negative effect on experience satisfaction and the pull factor(experience attributes, service quality)will have a positive effect on experience satisfaction. Also, mooring factors will have a negative effect on experience satisfaction. The research model of this study was tested by structural equation model based on 314 effective questionnaire data. Service quality had a positive effect on experience satisfaction. Mooring factors have a negative effect on experience satisfaction. Push factor and experience attributes factor were analyzed to have a no significance effect on experience satisfaction. These results theoretically test that the mooring factors also have an important effect on the experience satisfaction in the rural experience. Based on the Schmitt's Experience model and ServQual model introduced as a pull factor, the proposed unified PPM model proved to be a useful analysis framework. In practice, it was able to provide implications on what factors should be strategically and marketingly focused to activate the 6th industry experience.This study examined the impact of start-up education and mentoring on the intentions of business start-up, and verified through empirical analysis whether self-efficacy and resilience were mediated between them. The study surveyed 178 people in their 20s to 50s. The result analysis used the IBM SPSS Statistics 21.0 Statistical Package Program. The analysis performed a regression analysis for factor analysis, correlation analysis, and hypothesis verification. Empirical Research Results. First, it was confirmed that start-up education and mentoring affect on the intentions of business start-up. Second, study shows self-efficacy and resilience has an affect on the intentions of business start-up. Third, start-up education and mentoring affect on self-efficacy and resilience. Fourth, self-efficacy and resilience have been proven to be mediated when entrepreneurship education and mentoring affect on the intentions of business start-up. The results of the research proved that start-up education and mentoring provides and acts as a major role in improving the entrepreneurs' willingness when preparing a start-up. Furthermore, the study also shows the importance of start-up education and mentoring as a proactive variable to promote their will to start-up business. In addition, it was confirmed that the self-efficacy investigated in the preceding study translated into the will to start a business. It was particularly meaningful in that it tested the role of resilience, which was mainly studied in new variables, education and psychology.

A Verification on the Effectiveness of Middle Managers' Emotional Leadership in Food Service Management Companies (위탁급식업체 중간관리자의 감성리더십 효과성 검증)

  • Kim, Hyun-Ah;Jung, Hyun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.4
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    • pp.488-498
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    • 2007
  • The purposes of this study were to: a) provide evidences concerning the effects of emotional leadership b) examine the impacts of emotional leadership on employee-related variables, 'job satisfaction', 'organizational commitment', 'organizational performance' and 'turnover intention', and c) identify a conceptual framework underlying emotional leadership. A survey was conducted from August 23 to November 3, 2005 to collect data from mid-level managers in food service company headquarters (N=219). Statistical analyses were completed using SPSS Win (12.0) for descriptive, reliability, factor and correlation analyses and AMOS (5.0) for confirmatory factor analysis and structural equation modeling. The main results of this study were as follows. First, the managers gave the highest point to their leaders in the emotional leadership competence 'organizational awareness : reading the currents, decision networks, and politics at the organizational level' and gave the lowest point in the emotional leadership competence 'influence: wielding effective tactics for persuasion'. Second, the means of job satisfaction was above the midpoint (3 points). Employees' job satisfaction with 'coworkers' was relatively high. However, the extents of satisfaction with 'payroll' 'promotion', and 'work environment' were relatively low. Third, the organizational commitment was above the midpoint (3 points). In the organizational commitment, 'loyalty' factor was higher than 'commitment' factor. Fourth, the means of organizational performance was above the midpoint. The highest organizational performance variable was 'internal efficiency; trying to reduce cost' and the lowest organizational performance variable was 'internal fairness ; equitable treatment and all are treated with respect with no regard to status and grade'. Fifth, most respondents intended on 'thinking of quitting ; towards turnover process'. Sixth, the test of hypothesis using structural equation modeling found that emotional leadership produced p[Isitive effects on job attitude and job performance. Emotional leadership enhanced job satisfaction and organizational commitment, and in turn, employees' attitude positive effects on organizational performance; emotional leadership also had a direct impact on organizational performance

A Study on the Diffusion Factor of e-finance (e-Finance의 확산요인에 관한 연구)

  • Kim, Min-Ho;Song, Chae-Hun;Song, Sun-Yok;Cha, Sun-Kwon
    • International Commerce and Information Review
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    • v.4 no.2
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    • pp.253-277
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    • 2002
  • Nowaday, the advanced technology in information and communication has been leading the dramatic change of transaction paradigm expansion from physical basis to electronic one. As we know, financial services support most of financial exchange between two business parties. So the expansion of electronic transaction paradigm affects to every financial institutions which provide financial services. Thus, financial institutions have accepted e-Finance systems and providing internet financial services to live in the competition. The purpose of this study is to contribute the qualitative enhancement of its customer service, rapid diffusion and accurate strategy establishment for e-Finance industry in the user side. Through the literature review and factor and reliability analysis, this study selects six diffusion factors such as efficiency of perceived e-Finance, reliability and safety of e-Finance in perceived e-Finance itself's characteristic; confidence, technical factors and the customer service quality of e-Finance system in perception on e-Finance System; inclination to innovation in the personal characteristic. According to result of hypothesis verification by using logistics regression analysis, technical factors and the customer service quality of e-Finance system in perception on e-Finance System and inclination to innovation in the personal characteristic gave statistically positive effect to the diffusion decision at the significant level 0.05 and 0.01. However efficiency of perceived e-Finance, reliability and safety of e-Finance in perceived e-Finance itself's characteristic didn't affect to diffusion decision and confidence of e-Finance system in perception on e-Finance System didn't have any statistical significancy. This study can be used as a basic material for the forward empirical study of diffusion factors in the user side and be able to apply to company and government policy making or embodiment, determination for customer service quality degree of financial institutions. But this study has some limitations like didn't touch satisfaction factors and its effect, only deal domestic customers and didn't use multi-regression analysis.

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A Study on Matched Errors between PET and CT Images in PET/CT Examination According to Breathing Protocols (PET/CT 검사에서 호흡법에 따른 PET과 CT 영상의 정합오차)

  • Kim, Sang Un;Kwak, Dong Woo;Park, Hyeon Soo;Bang, Seong Ae;Park, Yeong Jae;LEE, In Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.1
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    • pp.7-10
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    • 2013
  • Purpose : This study evaluated the effects of breathing protocols on matching results of PET and CT images using two breathing protocols such as free breathing and acquisition in holding the breathing after the normal expiration in acquiring CT images. Materials and Methods: Whole body FDG PET and CT images of 200 patients (mean age: 58 (range 20~84), 103 males and 97 females) using Discovery VCT (GE Healthcare, Milwaukee, USA). When taking CT images, subjects were asked to breathe freely (free breathing, n=100) or hold the breathing after the normal expiration (Hold, n=100). In the whole body image coronal section where PET and CT were matched, the matched error of the boundary between diaphragm and liver was measured in length. The matched errors were compared according to breathing protocol by age, sex and disease. The verification of statistical significance was made by SPSS 15.0 (SPSS Inc., Chicago, IL, USA) via one way ANOVA. Results: The matched error in all was 0.87 mm. According to breathing protocol, there was no significant difference in matched error as1.01 mm in free breathing and as 0.73 mm in hold breathing (p=.688). The matched error according to sex did not show significant difference as 1.08 mm of males, and 0.93 mm of females in free breathing (p=.517). In hold breathing, there was no significant difference as 0.79 mm of males and 0.66 mm of females (p=.738). There was no significant difference in matched error by age between free breathing and hold breathing (free breathing (p=.728), hold (p=.465). There was no significant difference in matched error by disease between free breathing and hold breathing (free breathing (p=.197), hold (p=.518) Conclusion: The difference in matched error between free breathing and hold breathing was less than 5 mm at 99%. There was no statistically significant difference in matched error by breathing protocol, age and disease. It was proved that there was no difference in matched error between PET and CT images according to breathing protocol during PET/CT scan.

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The Evaluation of Radioimmunoassay kits for Insulin (Insulin 측정용 방사면역측정법 시약의 평가)

  • Shin, Yong Hwan;Kim, Yun Hyun;Lee, Il Kyu;Kim, Ji Young;Seok, Jae Dong;Shin, Suk Hee
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.149-155
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    • 2012
  • Purpose : Serum insulin levels are useful indicator which of reflecting the function of insulin secretion in pancreatic ${\beta}$ cell and diagnosis of diabetes, differentiating the cause of impaired glucose tolerance. Insulin measurement kits have shown some differences in many ways such as test methods as well as quality control. The purpose of this study was to evaluate the diagnostic performance of seven manufacturing companies commercial kits. Materials and Methods : The values of insulin measured by three manufacturing companies (Biosource, Siemens, TFB) with 59 samples in August 2009 were compared with those measured by four manufacturing companies (Immunotech, Izotope, BNIBT, Cisbio) with 68 samples in December 2011. We evaluated precision, recovery rate, dilution test and correlation of serum insulin measurement using seven manufacturing company kits. Statistical program SPSS 12.0 was used for the verification of results. Results : The coefficients variation of the precision on all seven different kits were showed within 5.0%. Recovery rate of Biosource, Siemens, TFB kits on three different levels showed 94.2~103.7%, 99.0~104.6%, 99.7~107.6% respectively. Immunotech, Izotope, BNIBT, Cisbio were 93.5~99.1%, 91.4~99.1%, 99.2~131.0%, 84.8~102.3% respectively. There was strong correlation between the measurement of insulin by Biosource kit and that by two commercial kits, Siemens (R2=0.96), TFB (R2=0.99). There was good correlation between the measurement of insulin by TFB kit and that by three commercial kits, Immunotech (R2=0.97), Izotope (R2=0.96), Cisbio (R2=0.97). In the dilution test performed with more than 200 ${\mu}IU/ml$ high concentration samples, samples with diabetes correctly was measured in all seven manufacturing kits. However, as measured with insulinoma samples TFB, Siemens, Izotope, Cisbio kits were correctly measured, but Biosource and Immunotech kits were measured 47.4 ${\mu}IU/ml$, 72.3 ${\mu}IU/ml$, respectively. Conclusion : Serum Insulin radioimmunoassay kits were showed excellent precision, correlation and good recovery rate. However, some kits were not measured correctly in the high concentration insulin values. when selecting a kit should be considered many factors that cost effectiveness, compatible for automation equipment, high performance kit, the environment for each laboratory such as reaction time and reporting time.

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Development of Neural Network Based Cycle Length Design Model Minimizing Delay for Traffic Responsive Control (실시간 신호제어를 위한 신경망 적용 지체최소화 주기길이 설계모형 개발)

  • Lee, Jung-Youn;Kim, Jin-Tae;Chang, Myung-Soon
    • Journal of Korean Society of Transportation
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    • v.22 no.3 s.74
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    • pp.145-157
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    • 2004
  • The cycle length design model of the Korean traffic responsive signal control systems is devised to vary a cycle length as a response to changes in traffic demand in real time by utilizing parameters specified by a system operator and such field information as degrees of saturation of through phases. Since no explicit guideline is provided to a system operator, the system tends to include ambiguity in terms of the system optimization. In addition, the cycle lengths produced by the existing model have yet been verified if they are comparable to the ones minimizing delay. This paper presents the studies conducted (1) to find shortcomings embedded in the existing model by comparing the cycle lengths produced by the model against the ones minimizing delay and (2) to propose a new direction to design a cycle length minimizing delay and excluding such operator oriented parameters. It was found from the study that the cycle lengths from the existing model fail to minimize delay and promote intersection operational conditions to be unsatisfied when traffic volume is low, due to the feature of the changed target operational volume-to-capacity ratio embedded in the model. The 64 different neural network based cycle length design models were developed based on simulation data surrogating field data. The CORSIM optimal cycle lengths minimizing delay were found through the COST software developed for the study. COST searches for the CORSIM optimal cycle length minimizing delay with a heuristic searching method, a hybrid genetic algorithm. Among 64 models, the best one producing cycle lengths close enough to the optimal was selected through statistical tests. It was found from the verification test that the best model designs a cycle length as similar pattern to the ones minimizing delay. The cycle lengths from the proposed model are comparable to the ones from TRANSYT-7F.