• Title/Summary/Keyword: 분류 기반 검정

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Technology Innovation Activity and Default Risk (기술혁신활동이 부도위험에 미치는 영향 : 한국 유가증권시장 및 코스닥시장 상장기업을 중심으로)

  • Kim, Jin-Su
    • Journal of Technology Innovation
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    • v.17 no.2
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    • pp.55-80
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    • 2009
  • Technology innovation activity plays a pivotal role in constructing the entrance barrier for other firms and making process improvement and new product. and these activities give a profit increase and growth to firms. Thus, technology innovation activity can reduce the default risk of firms. However, technology innovation activity can also increase the firm's default risk because technology innovation activity requires too much investment of the firm's resources and has the uncertainty on success. The purpose of this study is to examine the effect of technology innovation activity on the default risk of firms. This study's sample consists of manufacturing firms listed on the Korea Securities Market and The Kosdaq Market from January 1,2000 to December 31, 2008. This study makes use of R&D intensity as an proxy variable of technology innovation activity. The default probability which proxies the default risk of firms is measured by the Merton's(l974) debt pricing model. The main empirical results are as follows. First, from the empirical results, it is found that technology innovation activity has a negative and significant effect on the default risk of firms independent of the Korea Securities Market and Kosdaq Market. In other words, technology innovation activity reduces the default risk of firms. Second, technology innovation activity reduces the default risk of firms independent of firm size, firm age, and credit score. Third, the results of robust analysis also show that technology innovation activity is the important factor which decreases the default risk of firms. These results imply that a manager must show continuous interest and investment in technology innovation activity of one's firm. And a policymaker also need design an economic policy to promote the technology innovation activity of firms.

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A Study on the Job Productivity by the Smart Work Investment - Focused on the Organizational Change Resistance and the Communication - (스마트워크 투자에 따른 직무 생산성에 관한 연구 - 조직 변화저항과 의사소통을 중심으로-)

  • Jung, Byoung-Ho
    • Management & Information Systems Review
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    • v.37 no.3
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    • pp.83-113
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    • 2018
  • The purpose of this study to empirically examine a smart work investment and job performance by change resistance. Firstly, There investigates mediating role of the communication between the smart work investment and the job performance. Secondly, It will identify the job productivity differences through a level of organizational change resistance that reduced smart work investment. The smart work is to provide the flexibility of time and location and is a working method to improve a work productivity of organization members. The introduction of smart work means the adoption of new organizational culture, institution and technology and requires a novel change of a custom and pattern on existing organization culture and institution because of transformation form of communication and collaboration. The method of this study adopts a structural equation model to test a mediating effect of communication and a moderating effect of change resistance level. This model confirms whether smart work investments provide a positive impact on communication and organizational productivity. In addition, I will classify a change resistance level of smart work by cluster analysis and then check a critical path difference of job productivity between each group. As a result, The organizational IT, institution and culture on the smart work investment appeared to important influencers in communication and also had a direct influence of individual performance. Also, The three independent variables of smart work investment have an indirect influence of individual and organizational performance through communication mediating variables. However, the organizational IT and institution as independent variables do not provide direct influence of organization performance. Nevertheless, two independent variables of organizational IT and institution have an indirect influence the organization performance through communication mediating variables. As a result of confirming a productivity of three groups on organization resistance, there was a difference the individual and organizational performance among groups. The low-level group of organizational resistance showed high coefficient value of performance compared to other groups. The group analysis implications, The smart work investment appeared significantly to revise the institution first, build culture secondly and advanced technology lastly. The theoretical implication from this study contributes an extension of social science theory through socio-technical systems, institution, culture, change resistance and job performance based on smart work. The practical implications explain the smart work success in step-by-step investment rather than radical investment as level management of change resistance. In future research, the smart work performance between private and public firms will analyze a difference of the organizational culture, institution, technology and performance.

Analysing the Relationship Between Tree-Ring Growth of Quercus acutissima and Climatic Variables by Dendroclimatological Method (연륜기후학적 방법에 의한 상수리나무의 연륜생장과 기후인자와의 관계분석)

  • Moon, Na Hyun;Sung, Joo Han;Lim, Jong Hwan;Park, Ko Eun;Shin, Man Yong
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.2
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    • pp.93-101
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    • 2015
  • This study was conducted to analyze the relationship between tree-ring growth of Quercus acutissima and climatic variables by dendroclimatological method. Annual tree-ring growth data of Quercus acutissima collected by the $5^{th}$ National Forest Inventory (NFI5) were organized to analyze the spatial distribution of the species growth pattern. To explain the relationship between tree-ring growth of Quercus acutissima and climatic variables, monthly temperature and precipitation data from 1950 to 2010 were compared with tree-ring growth data for each county. When tree-ring growth data were analyzed through cluster analysis based on similarity of climatic conditions, four clusters were identified. In addition, index chronology of Quercus acutissima for each cluster was produced through cross-dating and standardization procedures. The adequacy of index chronologies was tested using basic statistics such as mean sensitivity, auto correlation, signal to noise ratio, and expressed population signal of annual tree-ring growth. Response function analysis was conducted to reveal the relationship between tree-ring growth and climatic variables for each cluster. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics of Quercus acutissima and for predicting changes in tree growth patterns caused by climate change.

A Study on the Spacial Environment Satisfaction for Evidence Based Design of Rehabilitative Health-Care Facilities -convergent approach for patient-centered rehabilitative healthcare service (근거중심 재활 공간 디자인을 위한 공간 환경 만족도 연구 -환자 중심 재활의료서비스를 위한 융복합적 접근)

  • Lee, Nakyung;Suh, Dasom;Song, Kyungeun
    • Journal of Digital Convergence
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    • v.15 no.10
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    • pp.327-337
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    • 2017
  • The purpose of this study is to investigate patient satisfaction for the spacial environment of the rehabilitative facilities, and by this to examine areas of patients' needs to develop patient-friendly improvement in spacial environment. 308 patients were surveyed at physical therapy centers of 6 hospitals or rehabilitative institutions in Daejeon with patient satisfaction questionnaire. The spatial environment satisfaction was categorized into 7 constructs and the data were statistically analyzed and compared by t-test and ANOVA according to the patient characteristics. As a result, inter-floor transfer was found to be the area with the least satisfaction, especially in the in-patient group. Locating floor level was the second lowest satisfied construct. Comfort was relatively highly satisfied construct overall, but patients with neurological disease had less satisfaction than with musculoskeletal disease. Patients in 20's were less satisfied in wayfinding than 60's. Satisfaction for interior design was lower in subject in 50's than 70's. These findings can be used as evidences to improve spacial environment design for rehabilitative facilities to the better patient satisfaction.

Investigation of Tube Voltage Range using Dose Comparison based on Effective Detector Exposure Index in Chest Radiography (흉부 X-ray 검사 시 선량 비교를 활용한 유효 Detector Exposure Index 기반의 적절한 관전압 범위 제안)

  • Shim, Jina;Lee, Youngjin
    • Journal of the Korean Society of Radiology
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    • v.15 no.2
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    • pp.139-145
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    • 2021
  • This study is to confirm the range of tube voltage for Chest X-ray in DR system by comparing with dose area product (DAP) and effective dose in efficient detector exposure index (DEI) range. GE definium 8000 was used to for the phantom study. The range of tube voltage is 60~130 kVp and of mAs is 2.5~40 mAs. The acquired images were classified into efficient DEI groups, then calculated effective dose with DAP by using a PC-Based Monte Carlo Program 2.0. The signal to noise ratio (SNR) was measured at 4 regions, including the thoracic spine, the lung area with the ribs, the lung area without the ribs, and the liver by using Picture Archiving and Communication System. The significance of the group for each tube voltage was verified by performing the kruskal-wallis test and the mann-whitney test as a post-test. When set to 4 groups dependned on the tube voltage, DAP showed significant differences; 60 kVp and 80 kVp, and 60 kVp and 90 kVp (p= 0.034, 0.021). Effective dose exhibited no statistically significant differences from the all of the group (p>0.05). SNR exhibited statistically significant differences from the all of the group in the liver except compared to 80 kVp and 90 kVp (p<0.05). Therefore, high tube voltages of 100 kVp or more need to be reconsidered in terms of patient dose and imaging in order to represent an appropriate chest X-ray image in a digital system.

Quantification of Schedule Delay Risk of Rain via Text Mining of a Construction Log (공사일지의 텍스트 마이닝을 통한 우천 공기지연 리스크 정량화)

  • Park, Jongho;Cho, Mingeon;Eom, Sae Ho;Park, Sun-Kyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.1
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    • pp.109-117
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    • 2023
  • Schedule delays present a major risk factor, as they can adversely affect construction projects, such as through increasing construction costs, claims from a client, and/or a decrease in construction quality due to trims to stages to catch up on lost time. Risk management has been conducted according to the importance and priority of schedule delay risk, but quantification of risk on the depth of schedule delay tends to be inadequate due to limitations in data collection. Therefore, this research used the BERT (Bidirectional Encoder Representations from Transformers) language model to convert the contents of aconstruction log, which comprised unstructured data, into WBS (Work Breakdown Structure)-based structured data, and to form a model of classification and quantification of risk. A process was applied to eight highway construction sites, and 75 cases of rain schedule delay risk were obtained from 8 out of 39 detailed work kinds. Through a K-S test, a significant probability distribution was derived for fourkinds of work, and the risk impact was compared. The process presented in this study can be used to derive various schedule delay risks in construction projects and to quantify their depth.

A Marketing Theory-Based Approach to Customer's Perceived Shopping Experience (고객의 지각된 쇼핑경험에 대한 마케팅 이론적 접근)

  • Yoon, Sung-Joon;Choi, Dong-Choon
    • Asia Marketing Journal
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    • v.10 no.1
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    • pp.95-131
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    • 2008
  • This study serves the main research purpose of verifying the hypothetical relationship between antecedent and consequence variables of shopping experience based on the classification system by Schmitt (1999) who dimensionalized experience into five components (sense, feel, think, act, relate). Specifically, the study seeks to fulfill the following three research objectives. First, it substantiates dynamic relationships among the five experiential components comprising the strategic experiential modules that serve as the basis of the theoretical framework of the study. Especially, it focuses on interactive relationships among the experiential components by taking a holistic view of the experience. Second, the study seeks to uncover the effects of pre-experiential antecedents such as shopping motivation and shopping involvement, based on taxonomy of motivation as product-centered vs. experience-centered. Third, the study investigates the effects of shopping experience on intention to revisit with regard to department store, discount store, and Internet shops, based on customers' store experiences. The major findings from this study are as follows: first, the five experiential components were found to have a high level of correlations according to hypothesis verification. Second, shopping motivation was learned to have significant effects on preference toward thinking as well as feeling experiences. That is, product-centered (vs. experience-centered) shopping motivation exerted a greater influence on cognitive (vs. affective experience than affective (vs. cognitive) experience.

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Evaluation of Germplasm and Development of SSR Markers for Marker-assisted Backcross in Tomato (분자마커 이용 여교잡 육종을 위한 토마토 유전자원 평가 및 SSR 마커 개발)

  • Hwang, Ji-Hyun;Kim, Hyuk-Jun;Chae, Young;Choi, Hak-Soon;Kim, Myung-Kwon;Park, Young-Hoon
    • Horticultural Science & Technology
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    • v.30 no.5
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    • pp.557-567
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    • 2012
  • This study was conducted to achieve basal information for the development of tomato cultivars with disease resistances through marker-assisted backcross (MAB). Ten inbred lines with TYLCV, late blight, bacterial wilt, or powdery mildew resistance and four adapted inbred lines with superior horticultural traits were collected, which can be useful as the donor parents and recurrent parents in MAB, respectively. Inbred lines collected were evaluated by molecular markers and bioassay for confirming their disease resistances. To develop DNA markers for selecting recurrent parent genome (background selection) in MAB, a total of 108 simple sequence repeat (SSR) primer sets (nine per chromosome at average) were selected from the tomato reference genetic maps posted on SOL Genomics Network. Genetic similarity and relationships among the inbred lines were assessed using a total of 303 polymorphic SSR markers. Similarity coefficient ranged from 0.33 to 0.80; the highest similarity coefficient (0.80) was found between bacterial wilt-resistant donor lines '10BA333' and '10BA424', and the lowest (0.33) between a late blight resistant-wild species L3708 (S. pimpinelliforium L.) and '10BA424'. UPGMA analysis grouped the inbred lines into three clusters based on the similarity coefficient 0.58. Most of the donor lines of the same resistance were closely related, indicating the possibility that these lines were developed using a common resistance source. Parent combinations (donor parent ${\times}$ recurrent parent) showing appropriate levels of genetic distance and SSR marker polymorphism for MAB were selected based on the dendrogram. These combinations included 'TYR1' ${\times}$ 'RPL1' for TYLCV, '10BA333' or '10BA424' ${\times}$ 'RPL2' for bacterial wilt, and 'KNU12' ${\times}$ 'AV107-4' or 'RPL2' for powdery mildew. For late blight, the wild species resistant line 'L3708' was distantly related to all recurrent parental lines, and a suitable parent combination for MAB was 'L3708' ${\times}$ 'AV107-4', which showed a similarity coefficient of 0.41 and 45 polymorphic SSR markers.

The prediction of the stock price movement after IPO using machine learning and text analysis based on TF-IDF (증권신고서의 TF-IDF 텍스트 분석과 기계학습을 이용한 공모주의 상장 이후 주가 등락 예측)

  • Yang, Suyeon;Lee, Chaerok;Won, Jonggwan;Hong, Taeho
    • Journal of Intelligence and Information Systems
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    • v.28 no.2
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    • pp.237-262
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    • 2022
  • There has been a growing interest in IPOs (Initial Public Offerings) due to the profitable returns that IPO stocks can offer to investors. However, IPOs can be speculative investments that may involve substantial risk as well because shares tend to be volatile, and the supply of IPO shares is often highly limited. Therefore, it is crucially important that IPO investors are well informed of the issuing firms and the market before deciding whether to invest or not. Unlike institutional investors, individual investors are at a disadvantage since there are few opportunities for individuals to obtain information on the IPOs. In this regard, the purpose of this study is to provide individual investors with the information they may consider when making an IPO investment decision. This study presents a model that uses machine learning and text analysis to predict whether an IPO stock price would move up or down after the first 5 trading days. Our sample includes 691 Korean IPOs from June 2009 to December 2020. The input variables for the prediction are three tone variables created from IPO prospectuses and quantitative variables that are either firm-specific, issue-specific, or market-specific. The three prospectus tone variables indicate the percentage of positive, neutral, and negative sentences in a prospectus, respectively. We considered only the sentences in the Risk Factors section of a prospectus for the tone analysis in this study. All sentences were classified into 'positive', 'neutral', and 'negative' via text analysis using TF-IDF (Term Frequency - Inverse Document Frequency). Measuring the tone of each sentence was conducted by machine learning instead of a lexicon-based approach due to the lack of sentiment dictionaries suitable for Korean text analysis in the context of finance. For this reason, the training set was created by randomly selecting 10% of the sentences from each prospectus, and the sentence classification task on the training set was performed after reading each sentence in person. Then, based on the training set, a Support Vector Machine model was utilized to predict the tone of sentences in the test set. Finally, the machine learning model calculated the percentages of positive, neutral, and negative sentences in each prospectus. To predict the price movement of an IPO stock, four different machine learning techniques were applied: Logistic Regression, Random Forest, Support Vector Machine, and Artificial Neural Network. According to the results, models that use quantitative variables using technical analysis and prospectus tone variables together show higher accuracy than models that use only quantitative variables. More specifically, the prediction accuracy was improved by 1.45% points in the Random Forest model, 4.34% points in the Artificial Neural Network model, and 5.07% points in the Support Vector Machine model. After testing the performance of these machine learning techniques, the Artificial Neural Network model using both quantitative variables and prospectus tone variables was the model with the highest prediction accuracy rate, which was 61.59%. The results indicate that the tone of a prospectus is a significant factor in predicting the price movement of an IPO stock. In addition, the McNemar test was used to verify the statistically significant difference between the models. The model using only quantitative variables and the model using both the quantitative variables and the prospectus tone variables were compared, and it was confirmed that the predictive performance improved significantly at a 1% significance level.

Analysis of the Distribution of Rice Blast Pathogens in High-Altitude North Korea Border Areas and Domestic Rice Cultivars (고위도 북한 접경지역과 국내 벼도열병균 레이스 분포 분석)

  • Jung Wook Yang;Eun Young Kim;Jin Kyo Jung;In Jeong Kang;Yul Ho Kim;Boyng Joo Kim;Un Ho Yang;Sunggi Heu;Hyunjung Chung
    • Research in Plant Disease
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    • v.29 no.3
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    • pp.243-250
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    • 2023
  • To explore the distribution and the resistance reaction of rice blast pathogens that may occur in North Korea, rice blast pathogens in the North Korean border regions of Dandong and Yeon-gil in China and the North Korean border region of Cheorwon in South Korea were analyzed. In addition, comparative analysis was conducted with rice blast pathogen in Suwon and Jeonju, inland regions of South Korea. Resistance reactions above average were observed in monogenic rice lines (IRBLzt-T, IRBL9-W, IRBL20-IR24, and IRBLta-CP1) in Jeonju, Suwon, and Cheorwon from 2018 to 2020. In Dandong and Yeon-gil, the monogenic lines IRBLz5-CA, IRBL12-M, and IRBL19-A consistently showed resistance reactions for three years. Notably, IRBL19-A exhibited strong resistance. Race distribution analysis in South Korea indicated a shift from KI to KJ dominance from 2018 to 2020, while in the North Korean border regions of Dandong and Yeon-gil, the KI race was dominant in 2021 and 2022. The race distribution of rice blast pathogens in China's North Korean border regions differed significantly from that in South Korea.