• Title/Summary/Keyword: 한계 속도

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A Study on the Evaluation of the Appropriateness of the Control of Departure of Tugs Based on the Analysis of Ship Dynamic Motion (선체운동 해석 기반의 예인선 출항통제 적정성 평가에 대한 연구)

  • Tae-Hoon Kim;Yong-Ung Yu;Yun-sok Lee;Young-Joong Ahn
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.4
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    • pp.307-315
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    • 2023
  • Korea controls the departure of vessels based on the Maritime Safety Act such that only ships with seaworthiness can navigate in bad weather, but scientific evaluation results and quantitative basis for the designation of ships subject to control are insufficient. Opinions for improvement are being raised for a reasonable departure control operation. The purpose of this study is to evaluate the adequacy of the current departure control standards through actual measurement of tugboats, which are the type of vessels subject to control when a wind and wave advisory is effective, and to present quantitative grounds for improvement of controls. A sensor was installed on the tugboat to measure the ship's three-axis motion and hull acceleration, and the hull motion performance was measured by operating in the sea area with a significant wave height of 3 m. The measured values were compared and analyzed based on seaworthiness evaluation factors and limit value standards. The actual ship was excluded from the current control standard according to tonnage, but as a result of the analysis, the pitch value exceeded the operation standard, and a risk to navigation safety existed. The results of this study suggest the need for additional actual measurement studies that can represent various ship types and specifications and review ship departure control targets.

A Search on building process of Trust in voluntary association in the community - A Subject of Expanding of Social Welfare Services - (지역사회 자발적 결사체의 신뢰형성 탐색 - 사회복지서비스 확대 시대의 과제 -)

  • Choi, Jong Hyug;Yu, Young Ju;Kim, Hyo Jung
    • Korean Journal of Social Welfare Studies
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    • v.41 no.3
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    • pp.135-162
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    • 2010
  • The Purpose of this study is to get basic material about voluntary association in local community and its utilization. In order to achieve the purpose of this study, it was considered that trust of social capital plays a leading part in voluntary association to maintain or strengthen its role and activities. For this reason we attempt to find the process of trust building in voluntary association. The revised ground theory that is complementary weaknesses of ground theory is used in this study and in 11months, four times researches have investigated. As a result, it was analyzed that the structure of building trust can be categorized into three structure, building up relationship, dynamic interaction and structural stabilization in voluntary association. In the space that is structured spatially and temporal, role, activity, accomplishment, attitude, conflict and environment acted as basic attributes. These attributes can be found in every building process of trust and influence on continuance and growth of voluntary association. The fact that this study offers in-depth understanding of voluntary association and empirical directivity regarding the community welfare services is of great significant.

Analyzing the Main Paths and Intellectual Structure of the Data Literacy Research Domain (데이터 리터러시 연구 분야의 주경로와 지적구조 분석)

  • Jae Yun Lee
    • Journal of the Korean Society for information Management
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    • v.40 no.4
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    • pp.403-428
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    • 2023
  • This study investigates the development path and intellectual structure of data literacy research, aiming to identify emerging topics in the field. A comprehensive search for data literacy-related articles on the Web of Science reveals that the field is primarily concentrated in Education & Educational Research and Information Science & Library Science, accounting for nearly 60% of the total. Citation network analysis, employing the PageRank algorithm, identifies key papers with high citation impact across various topics. To accurately trace the development path of data literacy research, an enhanced PageRank main path algorithm is developed, which overcomes the limitations of existing methods confined to the Education & Educational Research field. Keyword bibliographic coupling analysis is employed to unravel the intellectual structure of data literacy research. Utilizing the PNNC algorithm, the detailed structure and clusters of the derived keyword bibliographic coupling network are revealed, including two large clusters, one with two smaller clusters and the other with five smaller clusters. The growth index and mean publishing year of each keyword and cluster are measured to pinpoint emerging topics. The analysis highlights the emergence of critical data literacy for social justice in higher education amidst the ongoing pandemic and the rise of AI chatbots. The enhanced PageRank main path algorithm, developed in this study, demonstrates its effectiveness in identifying parallel research streams developing across different fields.

The Role of Relational Agency in a Need-reality Colliding Situation (욕구-현실 충돌 상황에서의 주체성의 역할)

  • Seheon Kim ;Taekyun Hur
    • Korean Journal of Culture and Social Issue
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    • v.29 no.4
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    • pp.617-636
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    • 2023
  • The goal of this study was to explain the phenomenon of making efforts to overcome the need-reality collision as a cultural characteristic of Koreans. Specifically, we examined whether the behavior varies depending on the degree of relational agency in the situation where conflicts between one's needs and reality have occurred. To this end, a total of 217 participants participated in the online experiment, and the data of 156 participants were finally analyzed. After responding to the relational agency scale, the participants were exposed to a decision-making scenario in which conflicting factors existed. The scenario were about buying a house and making a wedding hall contract, and in each scenario, two important values were set to conflict with each other in the market. Participants read the scenario and entered the level they wanted for each value. After that, they encounter a situation in which he or she has not found the candidate site corresponding to the level he or she wants. Then, the participants responded to their willingness to make additional efforts themselves. As a result of the study, the degree of relational agency of the participants showed a positive relationship with the degree of additional effort. In addition, the degree of the desired level beyond the reality (expectancy discrepancy) showed a nonlinear (reverse U-shape) influence on the additional effort while controlling for individual difference. Furthermore, the interaction effect between relational agency and expectancy discrepancy was significant. Specifically, individuals with low agency did not have a significant relationship between the degree of expectancy discrepancy and the dependent variable, but individuals with high relational agency had a significant non-linear relationship between the degree of expectancy discrepancy and the dependent variable. Based on the results of the study, the role and function of Koreans' psychological characteristics (relational agency) in the scene of managing needs-reality collision were discussed.

Study on the Occurrence of Tunnel Damage when a Large-scale Fault Zone Exists at the Top and Bottom of a Tunnel (대규모 단층대가 터널 상하부에 존재하는 조건에서 터널 변상 사례 연구)

  • Jeongyong Lee;Seungho Lee;Nagyoung Kim
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.12
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    • pp.53-60
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    • 2023
  • Recently, along with the improvement of high-speed rail and road design speed, the proportion of tunnel construction work is increasing proportionally. In particular, the construction of long tunnels is rapidly increasing due to the mountainous terrain of our country. In this way, due to the trend of tunnels becoming longer, it is difficult to design and construct tunnels by avoiding fault zones. In the case of tunnel construction in mountainous areas, ground investigation is often difficult even during design due to the topographical conditions, making precise ground investigation difficult, and as a result, the upper part of the tunnel is damaged during tunnel construction. When fault zones, which are vulnerable to weathering, exist, the stability of the tunnel during excavation is directly affected by the fault zone distribution, strength characteristics, and groundwater distribution range. In particular, when a fault zone is distributed in the upper part of a tunnel, damage such as tunnel collapse and excessive displacement may occur, and in order to prevent this in advance, countermeasures must be established through analysis of similar cases. Therefore, in this study, when a large-scale fault zone exists in the upper part of a tunnel, the relationship and characteristics of damage to the tunnel structure were analyzed.

Development of a Tourist Satisfaction Quantitative Index for Building a Rating Prediction Model: Focusing on Jeju Island Tourist Spot Reviews (평점 예측 모델 개발을 위한 관광지 만족도 정량 지수 구축: 제주도 관광지 리뷰를 중심으로)

  • Dong-kyu Yun;Ki-tae Park;Sang-hyun Choi
    • Journal of Intelligence and Information Systems
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    • v.29 no.4
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    • pp.185-205
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    • 2023
  • As the tourism industry recovers post the COVID-19 pandemic, an increasing number of tourists are utilizing various platforms to leave reviews. However, amidst the vast amount of data, finding useful information remains challenging, often leading to time and cost inefficiencies in selecting travel destinations. Despite ongoing research, there are limitations due to the absence of ratings or the presence of different rating formats across platforms. Moreover, inconsistencies between ratings and the content of reviews pose challenges in developing recommendation models. To address these issues, this study utilized 7,104 reviews of tourist spots in Jeju Island to develop a specialized satisfaction index for Jeju tourist attractions and employed this index to construct a 'Rating Prediction Model.' To validate the model's performance, we predicted the ratings of 700 experimental data points using both the developed model and an LSTM approach. The proposed model demonstrated superior performance with a weighted accuracy of 73.87%, which is approximately 4.67% higher than that of the LSTM. The results of this study are expected to resolve the discrepancies between ratings and review contents, standardize ratings in reviews without ratings or in various formats, and provide reliable rating indicators applicable across all areas of travel in different domains.

Effective Multi-Modal Feature Fusion for 3D Semantic Segmentation with Multi-View Images (멀티-뷰 영상들을 활용하는 3차원 의미적 분할을 위한 효과적인 멀티-모달 특징 융합)

  • Hye-Lim Bae;Incheol Kim
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.12
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    • pp.505-518
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    • 2023
  • 3D point cloud semantic segmentation is a computer vision task that involves dividing the point cloud into different objects and regions by predicting the class label of each point. Existing 3D semantic segmentation models have some limitations in performing sufficient fusion of multi-modal features while ensuring both characteristics of 2D visual features extracted from RGB images and 3D geometric features extracted from point cloud. Therefore, in this paper, we propose MMCA-Net, a novel 3D semantic segmentation model using 2D-3D multi-modal features. The proposed model effectively fuses two heterogeneous 2D visual features and 3D geometric features by using an intermediate fusion strategy and a multi-modal cross attention-based fusion operation. Also, the proposed model extracts context-rich 3D geometric features from input point cloud consisting of irregularly distributed points by adopting PTv2 as 3D geometric encoder. In this paper, we conducted both quantitative and qualitative experiments with the benchmark dataset, ScanNetv2 in order to analyze the performance of the proposed model. In terms of the metric mIoU, the proposed model showed a 9.2% performance improvement over the PTv2 model using only 3D geometric features, and a 12.12% performance improvement over the MVPNet model using 2D-3D multi-modal features. As a result, we proved the effectiveness and usefulness of the proposed model.

An Experimental Study on NOx Emissions with Hydrogen and Natural gas Co-firing for EV burner of GT24 (GT24 가스터빈용 EV 버너의 수소혼소에 따른 질소산화물 배출 특성에 대한 실험적 연구)

  • Jeongjae Hwang;Won June Lee;Kyungwook Min;Do Won Kang;Han Seo Kim;Min Kuk Kim
    • Journal of the Korean Institute of Gas
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    • v.27 no.4
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    • pp.85-91
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    • 2023
  • In this study, an experimental study was conducted on the flame behavior, combustion dynamics, and NOx emission characteristics for hydrogen co-firing with the EV burner which is the first stage combustor of GT24. It was confirmed that as the hydrogen co-firing rate increases, the NOx emission increases. This change was elucidate to be the result of a combination of changes in penetration depth due to changes in fuel density, reduction in fuel mixing due to changes in flame position due to increased flame propagation speed, and oscillation of fuel mixedness due to combustion instability. Through pressurization tests in the range of 1.3 to 3.1 bar, NOx emission characteristics under high-pressure operating conditions were predicted, and based on this, the hydrogen co-firing limits of the EV burner was evaluated.

The Effects of Compensation and Pay Dispersion on Organizational Productivity and Performance: The Case of Korean Professional Basketball Teams (한국프로농구 기업의 임금수준과 임금격차가 구성원의 생산성과 조직성과에 미치는 영향: 한국프로농구를 중심으로)

  • PHILSOO KIM;TAE SUNG JEONG;SANG HYUN LEE
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.2
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    • pp.127-139
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    • 2023
  • Compensation and pay dispersion has been rigorously scrutinized to investigate their impacts on productivity and organizational performance. However, it is difficult to find a systematic study on the systematic dynamics of compensation and pay dispersion effects specifically in the context of Korean venture companies. Venture companies should manage their organizational resources efficiently to maximize their organizational performance through pay structure by efficiently managing the inherent resources. However, we acknowledge that empirical studies on how compensation and pay dispersion affect organizational productivity and performance are rare to find in the Korean context. To overcome this supplement limitation, this study hypothesized that (1) pay and members' productivity are positively related, (2) pay dispersion and organizational productivity have U shaped relationship, and (3) organizational productivity mediates the positive relationship between compensation and organizational performance. Venture companies and professional sports teams share manifold common characteristics such as size, financial circumstances, and operational objectives. We collect 9 seasons (2013~2014 - 2021~2022) of 10 teams' data of Korean Basketball League teams to test our hypotheses. Methodologically, the assessment of our analysis is rendered with PROCESS macro model 58. The statistical results showed that all hypotheses are statistically supported. This study explains how compensation and pay dispersion affect organizational productivity and performance of venture companies in Korea.

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The Effects of Social Entrepreneurship and Blended Value Orientation on Performance of Social Enterprises (사회적 기업가정신과 혼합가치 지향성이 사회적 기업의 성과에 미치는 영향)

  • Yoo, Hanna;Jeong, EuiBeom
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.1
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    • pp.213-227
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    • 2022
  • Recently, research on social entrepreneurship, which simultaneously pursues social value creation and economic sustainability has increased rapidly. Researchers conducted several empirical studies, noting that social entrepreneurship is a major factor in improving the performance of social enterprises. However, most previous studies usually have limitations in measuring the performance of social enterprises based on the subjective perception of entrepreneurs, which implies the limitations of the common method bias. In addition, there is a lack of empirical evidence that can explain the specific process in which the personal characteristic of an entrepreneur, social entrepreneurship, affects the achievement of dual goals. Therefore, this study empirically investigates the effect of social entrepreneurship on performance increasing the objectivity of performance measurement and including blended value orientation(BVO), a characteristic of viewing social and economic performance as a single thing. The purpose of the study is to verify the effect of social entrepreneurship and BVO on the social and economic performance of social enterprises. We conducted regression analysis using the results of the perception survey of social enterprises in South Korea and objective performance data. As a result, risk-taking, a sub-factor of social entrepreneurship, had a positive effect on economic and social performance at a significant level. In addition, it was confirmed that social entrepreneurship improves BVO, and it affects social performance. Therefore, this study found that social entrepreneurship and BVO have a discriminatory effect on economic and social performance, respectively. This study is meaningful in that it attempted to overcome the common method bias as measuring subjectivity performance.