• Title/Summary/Keyword: 데이터 과학

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Prospect Theory and Risk Preferences of Real Estate Development Companies (부동산 개발 및 공급 기업의 손익과 경영진의 위험 선호도)

  • Kim, Byungil;Kim, Won Tae;Chung, Do-Bum
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.1
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    • pp.83-88
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    • 2022
  • Companies make decisions with risks such as choosing an investment plan in order to pursue profits. This study explained the decision making of the management of construction companies in South Korea using the tendency to avoid losses in the Prospect Theory. To this end, 20-year financial data of 2,881 companies engaged in real estate development, which have to bear the greatest risk among the construction industry, were collected. The collected companies were roughly classified based on the reference point, and the causal relationship between average return on equity and risk preference by group was empirically analyzed through regression analysis. As a result, it was confirmed that if the average return on equity of a company decreases for the group above the reference point, it tends to select an investment plan with low uncertainty in order not to lose additional money. In addition, it was confirmed that if the average return on equity of a company decreases for the group below the reference point, it tends to select an investment plan with high uncertainty to move to the profit area. This result is exactly consistent with the loss aversion tendency of the Prospect Theory.

The Accuracy of Genomic Estimated Breeding Value Using a Hanwoo SNP Chip and the Pedigree Data of Hanwoo Cows in Gyeonggi Province (한우 SNP Chip 및 혈통 데이터를 이용한 경기 한우 암소의 유전능력평가 정확도 분석)

  • Lee, Gwang Hyeon;Lee, Yoon Seok;Moon, Seon Jeong;Kong, Hong Sik
    • Journal of Life Science
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    • v.32 no.4
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    • pp.279-284
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    • 2022
  • This study was conducted to establish a genetic evaluation system applicable to general farms for improving cows raised on farms. The analysis used Best Linear Unbiased Prediction (BLUP) and Genomic Best Linear Unbiased Prediction (GBLUP) for 619 cows raised in Gyeonggi-do Province and compared and analyzed the accuracy of the estimated breeding value according to four traits (carcass weight, loineye muscle area, back fat thickness, and marbling). In the case of the GBLUP method, the size of the reference population was divided into different four groups and analyzed. The analysis results confirmed that the accuracy of the breeding value of each trait increased as the size of the GBLUP reference population increased. Comparing the accuracy of the breeding values estimated using the BLUP and GBLUP methods, it was confirmed that when the breeding values were estimated using the GBLUP method, they increased by 0.10, 0.09, 0.09, and 0.11 for carcass weight, eye muscle area, back fat thickness, and marbling scores, respectively. Applying the GBLUP method to the evaluation and selection of cows can enable precise and accurate individual selection, while increasing the size of the reference population can make even more accurate individual selection possible, thus increasing selection efficiency.

Mobile Health Applications Adoption for the Management of Smartphone Overdependence (스마트폰 과의존 관리를 위한 모바일 건강관리 어플리케이션 수용 모델)

  • Rho, Mi Jung
    • Korea Journal of Hospital Management
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    • v.26 no.4
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    • pp.12-28
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    • 2021
  • Purposes: The convenience of smartphones have lead to people's overdependence on devices, which may cause obstacles in daily life. It is useful to manage smartphone overdependence by using mobile health applications. We aimed to investigate the acceptance of mobile health applications designed to help in the management of smartphone overdependence. Methodology/Approach: We developed the extended model based on the Unified Theory of Acceptance and Use of Technology 2. The modified model had six hypotheses with six variables: result demonstrability, performance expectancy, effort expectancy, social influence, perceived risk, and behavioral intention to use. We randomly included 425 smartphone users in an online survey in 2020. A structural equation model was used to estimate the significance of the path coefficients. Findings: Performance expectancy and social influence had a very strong direct positive association with behavioral intention to use. Result demonstrability had a direct positive association with performance expectancy. Perceived risk had a strong direct negative association with performance expectancy. Performance expectancy and social influence were the main factors directly influencing the acceptance of mobile health applications for the management of smartphone overdependence. Practical Implications: We demonstrated smartphone users' acceptance of mobile health applications for smartphone overdependence management. Based on these results, we could develop mobile health applications more effectively.

Hematopoietic Stem Cells and Bone Marrow Microenvironment: Current and Emerging Concepts (골수 미세환경에서 조혈줄기세포의 기능조절에 대한 고찰- 현재 및 새로운 개념)

  • Lee, Won Jong;Park, Seong Hyun;Park, Jun Hee;Oh, Seong Hwan;Lee, Dongjun
    • Journal of Life Science
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    • v.32 no.6
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    • pp.468-475
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    • 2022
  • The functional distinction between stem and progenitor cells is well established in several tissues, particularly in the blood. There, hematopoietic stem cells preserve their self-renewal potential and reconstitution ability in the bone marrow niche. Bone marrow represents a unique setting in which to examine how stroma influences tissue function. It was the setting in which the experimental definition of a niche was first provided in mammalian stem cell biology and where clear evidence for non-cell-autonomous oncogenesis was first defined. The relationship between bone and blood is ancient as all animals since the divergence of fish that have bones and blood, make blood in their bones. This long coevolution engendered complex interrelationships, including the first proposed and first experimentally defined niche for stem cells in mammals. Multiple bone marrow stromal cell types serve as regulators of hematopoiesis, and the dysfunction of some causes myelodysplasia and leukemia. However, no comprehensive atlas of stromal subpopulations exists. Therefore, we think these data point to something of importance, such as how the needs and challenges of the organism become translated down to distinct cell types that critically govern specific functions within tissues and do so at the level of a single molecule. We think this will be of broad interest to those focusing on systems biology and the physiology of organisms, particularly those seeking a molecular basis for understanding cell and tissue behavior. We summarized the current and emerging concepts of hematopoietic stem cells and bone marrow niche.

Direct blast suppression for bi-static sonar systems with high duty cycle based on adaptive filters (고반복률을 갖는 양상태 소나 시스템에서의 적응형 필터를 이용한 송신 직접파 제거 연구)

  • Lee, Wonnyoung;Jeong, Euicheol;Yoon, Kyungsik;Kim, Geunhwan;Kim, Dohyung;You, Yena;Lee, Seokjin
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.4
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    • pp.446-460
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    • 2022
  • In this paper, we propose an algorithm to improve target detection rate degradation due to direct blast in a bi-static sonar systems with high duty cycle using an adaptive filters. It is very important to suppress the direct blast in the aforementioned sonar systems because it has a fatal effect on the actual system operation. In this paper, the performance was evaluated by applying the Normalized Least Mean Square (NLMS) and Recursive Least Square (RLS) algorithms to the simulation and sea experimental data. The beam signals of the target and direct blast bearings were used as the input and desired signals, respectively. By optimizing the difference between the two signals, the direct blast is removed and only the target signal is remained. As a result of evaluating the results of the matched filter in the simulation, it was confirmed that the direct blast was removed to the noise level in both Linear Frequency Modultated (LFM) and Generalized Sinusoidal Frequency Modulated (GSFM), and in the case of GSFM, the target sidelobe decreased by more than 20 dB, thereby improving performance. In the sea experiment, it was confirmed that the LFM reduced the level of the transmitted direct wave by 10 dB, the GSFM reduced the level of the transmitted direct wave by about 4 dB, and the side lobe of the target decreased by about 4 dB, thereby improving the performance.

A Statistical Study on the Result Analysis of CaPSPI, a Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification (CaPSPI(Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification) 업그레이드를 위한 검진용 치료용 진단 결과 분석에 대한 통계 연구)

  • Kim, Tae-Hee;Lee, In-Seon;Kim, Jong-Won;Jeon, Soo-Hyung;Chi, Gyoo-Yong;Kang, Chang-Wan
    • The Journal of Korean Obstetrics and Gynecology
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    • v.35 no.3
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    • pp.105-121
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    • 2022
  • Objectives: It is a statistical analysis study to examine the results of CaPSPI (Diagnostic System for Climacteric and Postmenopausal Syndrome Pattern Identification), developed for objective defecation of climacteric and postmenopausal syndrome. Methods: Total 341 people's questionnaire responses were statistically analyzed. 275 people involved in developing CaPSPI 2018 (E) and 146 people involved in 2019-2020 study of research1,3). Results: The frequency of diagnosis for examination was the highest at liver depression, 93.8% for 320 times, the lowest at heartheat, 62.8% for 214 times. The frequency of treatment for examination was the highest at liver depression, 54.3% for 185 times, and the lowest at dual deficiency of heart-spleen, 16.7% for 57 times. The diagnosis ratio was the lowest at dual deficiency of heart-spleen, 19.72%, and the highest at liver depression, 57.81%. As a result of comparing these diagnoses with the Kupperman's index, all showed significant differences. As a result of comparing these disease elements, all showed significant differences. The correlation between diagnosis and dialectic elements was found to have similar results with the korean medical pathology, and in 7 dialectics except for heartheat, the treatment version was more severe or progressing to perjury than for examination. Conclusions: The CaPSPI shows the characteristics of korean medicine well, and it is needed to utilize the high correlative disease elements to upgrade the system.

Analysis of Research Trends in Tax Compliance using Topic Modeling (토픽모델링을 활용한 조세순응 연구 동향 분석)

  • Kang, Min-Jo;Baek, Pyoung-Gu
    • The Journal of the Korea Contents Association
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    • v.22 no.1
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    • pp.99-115
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    • 2022
  • In this study, domestic academic journal papers on tax compliance, tax consciousness, and faithful tax payment (hereinafter referred to as "tax compliance") were comprehensively analyzed from an interdisciplinary perspective as a representative research topic in the field of tax science. To achieve the research purpose, topic modeling technique was applied as part of text mining. In the flow of data collection-keyword preprocessing-topic model analysis, potential research topics were presented from tax compliance related keywords registered by the researcher in a total of 347 papers. The results of this study can be summarized as follows. First, in the keyword analysis, keywords such as tax investigation, tax avoidance, and honest tax reporting system were included in the top 5 keywords based on simple term-frequency, and in the TF-IDF value considering the relative importance of keywords, they were also included in the top 5 keywords. On the other hand, the keyword, tax evasion, was included in the top keyword based on the TF-IDF value, whereas it was not highlighted in the simple term-frequency. Second, eight potential research topics were derived through topic modeling. The topics covered are (1) tax fairness and suppression of tax offenses, (2) the ideology of the tax law and the validity of tax policies, (3) the principle of substance over form and guarantee of tax receivables (4) tax compliance costs and tax administration services, (5) the tax returns self- assessment system and tax experts, (6) tax climate and strategic tax behavior, (7) multifaceted tax behavior and differential compliance intentions, (8) tax information system and tax resource management. The research comprehensively looked at the various perspectives on the tax compliance from an interdisciplinary perspective, thereby comprehensively grasping past research trends on tax compliance and suggesting the direction of future research.

A research on the Construction and Sharing of Authority Record-focusing on the Case of Social Networks and Archival Context Project (전거레코드 구축 및 공유에 관한 연구 SNAC 프로젝트 사례를 중심으로)

  • Lee, Eun Yeong
    • The Korean Journal of Archival Studies
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    • no.71
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    • pp.49-89
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    • 2022
  • This study suggests the necessity and domestic application plan a national authority database that promotes an integrated access, richer search, and understanding of historical information sources and archival resources distributed among cultural heritage institutions through the "Social Networks and Archive Context" project case. As the SNAC project was transformed into an international cooperative organization led by NARA, it was possible to secure a sustainable operating system and realize cooperative authority control. In addition, SNAC authority records have the characteristics of providing richer contextual information about life and history and social and intellectual network information compared to libraries. Through case analysis, First, like SNAC, a cooperative body led by the National Archives and having joint ownership of the National Library of Korea should lead the development and expand the scope of participating institutions. Second, in the cooperative method, take a structure in which divisions are made for each field with special strengths, but the main decision-making is made through the administrative team in which the two organizations participate. Third, development of scalable open source software that can collect technical information in various formats when constructing authority data, designing with the structure and elements of archival authority records, designing functions to control the quality of authority records, and building user-friendly interfaces and the need for a platform design reflecting content elements.

Effect of Disability Types by Disability Severity Levels on Employment: Based on the Employment Panel Survey for the Disabled (장애 중증도 수준에 따른 장애 유형이 고용에 미치는 영향: 장애인고용패널조사를 중심으로)

  • Choi, Junhyeok;Lee, Jisoo;Chung, Sunwoo;Oh, Sung Soo;Jo, Hoon
    • Therapeutic Science for Rehabilitation
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    • v.11 no.2
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    • pp.63-76
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    • 2022
  • Objective : The purpose of this study is to examine the relationship with employment of the disabled considering the severity and the type of disability. Methods : Data from the 4th data of the 2nd wave Panel Survey of Employment for the Disabled (PSED) by Korea Employment Agency for Persons with Disabilities (KEAD) were used. The odds ratio of employment in disability types according to severity of disability was calculated by logistic regression analysis. Results : When the related variables were adjusted, the employment of internal disability type was significantly lower than that of external disability type by 0.413(95% CI:0.271-0.629) times in the group with severe disability. On the other hand, in the group with less severe disability, internal disability was 0.475(95% CI:0.327-0.690) times lower than that of external disability (p=<.001). Conclusions : Employment may vary depending on the type of disability, even if the disability severity level is the same. It is necessary to prepare judgment criteria that can reduce the variation in employment by considering both the type and severity of the disability.

Autonomic Nerve Change after Loess Bedding Radiating Far-infrared ray and energy (원적외선에너지 방출 황토침구 사용 후의 자율신경 변화에 대한 연구)

  • Lee, Ku Yeon;Lee, Hyung H.;Hahm, Suk Chan
    • Journal of Naturopathy
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    • v.9 no.1
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    • pp.27-32
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    • 2020
  • Purpose: The purpose of this study was to investigate the changes in the autonomic nervous system of the human body after the use of ocher bedding radiating far-infrared rays to 15 insomnia subjects. Methods: Changes of autonomous nerve in the subjects after using loess bedding estimated by heart rate variability. Results: The mean HF before the use of ocher bedding was 220.8 msec2, and the mean after use decreased to 5.1 msec2. The average value of LF before use was 418.1 msec2, and the mean after use decreased to 5.2 msec2. The average before use of the VLF was 1463.3 msec2, and the average after use dropped to 6.8 msec2. The average value of TP before use was 977.3 msec2, and the average after use dropped to 6.7 msec2. The decrease in postoperative values of all four items was statistically significant, and the high value of the subjects before use inferred to be the reason that all of the subjects had high stress and anxiety due to their long-term sleep disorder. There was no significant difference in the pulses of the subjects before the use of the bedding. SDNN and RMSSD were not significantly different before and after use. Conclusions: Autonomic nerves HF, LF, VLF, TP frequency is evaluated to be affected by the investigation of far-infrared radiation that occurs ocher. This research data regarded as high value as primary data in this field.