• Title/Summary/Keyword: Potential theory

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Introduction of Inverse Analysis Model Using Geostatistical Evolution Strategy and Estimation of Hydraulic Conductivity Distribution in Synthetic Aquifer (지구통계학적 진화전략 역산해석 기법의 소개 및 가상 대수층 수리전도도 분포 예측에의 적용)

  • Park, Eungyu
    • Economic and Environmental Geology
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    • v.53 no.6
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    • pp.703-713
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    • 2020
  • In many geological fields, including hydrogeology, it is of great importance to determine the heterogeneity of the subsurface media. This study briefly introduces the concept and theory of the method that can estimate the hydraulic properties of the media constituting the aquifer, which was recently introduced by Park (2020). After the introduction, the method was applied to the synthetic aquifer to demonstrate the practicality, from which various implications were drawn. The introduced technique uses a global optimization technique called the covariance matrix adaptation evolution strategy (CMA-ES). Conceptually, it is a methodology to characterize the aquifer heterogeneity by assimilating the groundwater level time-series data due to the imposed hydraulic stress. As a result of applying the developed technique to estimate the hydraulic conductivity of a hypothetical aquifer, it was confirmed that a total of 40000 unknown values were estimated in an affordable computational time. In addition, the results of the estimates showed a close numerical and structural similarity to the reference hydraulic conductivity field, confirming that the quality of the estimation by the proposed method is high. In this study, the developed method was applied to a limited case, but it is expected that it can be applied to a wider variety of cases through additional development of the method. The development technique has the potential to be applied not only to the field of hydrogeology, but also to various fields of geology and geophysics. Further development of the method is currently underway.

Effect of Bundling Strategy on Tourists' Evaluation of Tour Packages (여행 패키지의 묶음판매 전략에 관한 연구)

  • Kim, Seung Lee;Lee, Dong Hee
    • International Area Studies Review
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    • v.16 no.1
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    • pp.53-74
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    • 2012
  • The bundling of multiple products/services at a set price has become a popular marketing strategy. However, little is known on how effects of bundling strategy influence tourists' evaluation of tour packages. Tourists evaluate a tour package based on the trade-off between the perceived benefits and costs involved in purchasing the tour package. In other words, the perceived value of the tour package influenced whether tourists to purchase a tour package or not. This study tested a tour package based on the theory of bundling, taking a moderating approach with perceived value. The data for this study wascollected by subjects who live Seoul Metropolitan Area and Gyeonggi Province and 4234 respondents, potential tourists to northeastern U.S.A/Canada. Results show that bundling taken by travel agencies include how many product items to put in a tour package and what degree of discount for the tour package. Also explaining functional relationship among product items in the tour package. Result show that tourists expect a discount, large or small, from purchasing a tour package. And the larger the number of products in a tour packages, the larger the discount size, and low functional relationship among items tourists expect to get.

A Study on the Creation Process of Dance based on the Concept of Murray Schafer's Soundscape (Murray Schafer의 사운드스케이프 개념을 바탕으로 한 무용작품 의 창작과정 연구)

  • Ra, Se-Young;Choe, Sang-Cheul
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.425-434
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    • 2021
  • This study is subjected to two linked research. First is the creation process of dance work applying noise and non-musical sounds in our daily life based on understanding the classification, perception, and factor of the sound, through Murray Schafer's concept of 'soundscape'. Second is to find the value of new type of choreography and musical effect of creation process of the dance work . According to methodological research of practice-based research, three stages which is practice, theory and evaluation were accumulated as somatic data, And the analysis was provided a basis by presenting in a figuration, form of the movement and method of specialization with reference to the paper 『space design and forming practice』(2003). As a result, the creation process was able to discover the musical effect of the sound in daily life and new method of choreography, and also find the possibilities that sound could convey the theme of the dance work, the meaning of the movement and the overall atmosphere of the work to audience. In addition, It is expected that will have been made another new creation environment by potential that music has based on concept 'soundscape'.

Performance Assessment of Navigation Seakeeping for Coastal Liquified-Natural-Gas Bunkering Ship (연안선박용 LNG 벙커링 전용선박의 내항성능 평가에 대한 연구)

  • Yi, Minah;Park, Jun-Bum;Lee, Chang-Hee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.7
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    • pp.904-914
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    • 2020
  • Through the Ministry of Trade, Industry, and Energy, South Korea is trying to support the "Building Project for Liquified Natural Gas (LNG) Bunkering Ship," centered on the Korea Gas Corporation, while the Ministry of Maritime Af airs and Fisheries is pushing to construct an LNG bunkering terminal at Busan New Port. LNG bunkering ships are essential for supplying LNG fuel from the terminal to the ships, resulting in the need for safety operation procedures. Therefore, in this study, the stability of a coastal LNG bunkering ship operating from Busan New Port to the anchorage in Busan Port was assessed to investigate the need for operational procedures for coastal LNG bunkering ships. Seakeeping analysis of the LNG bunkering ship was performed for each significant wave height by combining the response amplitude operator from the ship motion analysis under the potential flow theory with the actual observed sea data for five years and Texel, Marsen, and Arsloe (TMA) spectrum suitable for the Busan coast. The results showed that the roll and horizontal acceleration were the main risks that affected the navigation seakeeping performance above a significance wave height of 2 m. The operational periods of the LNG bunkering ship ranged from 83.3% to 99.9% of the total observation period.

Trait Positive Affect and OCBI : The Moderating Role of Perceived Group Positive Affect and the Mediating Role of Group Identification (긍정적 정서성향과 조직시민행동 : 긍정적 집단 분위기 인식의 조절효과와 집단정체감의 매개효과를 중심으로)

  • Kim, Moon Joung
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.1
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    • pp.416-423
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    • 2021
  • Drawing upon research in affect and social identity theory, this study examines when and how an individual's trait positive affect (TPA) exerts a significant effect on the person's organizational citizenship behavior directed toward individuals (OCBI). A moderated mediation model was tested by using the data of 293 employees nested in 66 work groups. Results demonstrate that the indirect effect of TPA on OCBI mediated by group identification (GI) is significantly positive only when perceived group positive affect (PGPA) is low, highlighting the substituting role of PGPA in the relationship between TPA and GI. The significant conditional indirect effects at the low level of PGPA suggest that TPA functions as significant, affective resources for enhancing GI and consequently increasing OCBI of the focal member when PGPA is low. By contrast, TPA's role in enhancing GI becomes redundant when PGPA is high. The current analysis reveals potential complementary functions of TPA and PGPA in explaining subsequent identity cognition and individual behavior.

A Study on the Influence of Sentiment and Emotion on Review Helpfulness through Online Reviews of Restaurants (레스토랑의 온라인 리뷰를 통해 감성과 감정이 리뷰 유용성에 미치는 영향에 관한 연구)

  • Yao, Ziyan;Park, Jiyoung;Hong, Taeho
    • Knowledge Management Research
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    • v.22 no.1
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    • pp.243-267
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    • 2021
  • Sentiment represents one's own state through the process of change to stimulus, and emotion represents a simple psychological state felt for a certain phenomenon. These two terms tend to be used interchangeably, but their meaning and usage are different. In this study, we try to find out how it affects the helpfulness of reviews by classifying sentiment and emotion through online reviews written by online consumers after purchasing and using various products and services. Recently, online reviews have become a very important factor for businesses and consumers. Helpful reviews play a key role in the decision-making process of potential customers and can be assessed through review helpfulness. The helpfulness of reviews is becoming increasingly important in practice as it is utilized in marketing strategies in business as well as in purchasing decision-making issues of consumers. And academically, the importance of research to find the factors influencing the helpfulness of reviews is growing. In this study, Yelp.com secured reviews on restaurants and conducted a study on how the sentiment and emotion of online reviews affect the helpfulness of reviews. Based on the prior research, a research model including sentiment and emotions for online reviews was built, and text mining analyzes how the sentiment and emotion of online reviews affect the helpfulness of online reviews, and the difference in the effects on emotions It was verified. The results showed that negative sentiment and emotion had a greater effect on review helpfulness, which was consistent with the negative bias theory.

Assessing Conservation Priority of Private Land in Unexecuted Urban Parks in Seoul Using Betweenness Centrality Analysis (매개중심성 분석을 활용한 서울시 미집행공원 내 사유지 보전 우선순위 평가)

  • Hwang, Byungmook;Ko, Dongwook W.;Kang, Wanmo
    • Journal of Korean Society of Forest Science
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    • v.110 no.1
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    • pp.22-34
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    • 2021
  • The implementation of the sunset provision of unexecuted urban parks in Seoul has been postponed; however, the mentioned parks still remain vulnerable since they can be subject to development under certain circumstances. Local governments may purchase the parks to prevent their loss but are constrained due to limited resources. The purpose of this study is to prioritize the purchase of unexecuted urban parks in Seoul based on landscape connectivity, which represents the important role of allowing the movement of wildlife and providing biodiversity in urban environments. In this study, we used four potential scenarios (PB100, PB1, PA100, PA1), which reflects the degree of land cover change resulting from the implementation of the sunset provision, and the role of Han River as a conduit or barrier for wildlife movement. Landscape connectivity was evaluated by calculating current flow betweenness centrality (CFBC). This was used to rank the importance of the unexecuted urban parks in Seoul. The results demonstrated that the implementation of the sunset provision will greatly decrease the connectivity of all parks in Seoul and particularly more so for parks in the southern part of the city. In addition, the results suggested that the low connectivity of Han river will diminish the connectivity around Bukhansan Mountain in the northern part of Seoul. Our study can be used for the prioritization of purchase, since it has the ability to evaluate the anticipated vulnerability of each park's connectivity after the sunset provision.

A Comparative Study of Ship Collision Legislation in Korea and China (한국과 중국의 선박충돌법제의 비교법적 연구)

  • Jiancuo, Qi
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.4
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    • pp.577-586
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    • 2022
  • The increasing trade volume between Korea and China has rapidly expanded the maritime transport between the two countries. However, safety, particularly considering the ship collisions in the Yellow Sea and East Sea waters, has not been fully ensured. These collision accidents in that region endanger traffic safety and the marine environment, moreover, it has the potential to cause legal complexity because Korea and China haver domestic legislation, that are considerably different in some aspects. International conventions and domestic legislation in China provide detailed laws with respect to ship collisions, however, the theory of ship collision infringement still needs to be improved, enriched, and developed. Because these laws are not very clear on the resolution of disputes resulting from ship collisions, we focused on the final judgments by the Supreme Court of China (SPC), and the judicial judgments set by the Maritime Court of China. This study aimed to explore the domestic legislation applicable to disputes related to ship collisions in China, and comparatively investigate the legal provisions of Korea and China on the issue of ship collisions, particularly on the aspect of damage compensation, fault ration, and liability apportionment.

Proposal on Active Self Charging and Operation of Autonomous Vehicle Using Solar Energy (태양광을 이용한 자율주행 자동차의 능동적 자가 충전 및 운행 제안)

  • Hur, Hyun-Woo
    • The Journal of the Korea Contents Association
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    • v.22 no.9
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    • pp.85-94
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    • 2022
  • In modern society, environmental and energy problems have caused to replace cars with environment friendly energy. Vehicles with internal combustion engine which use petroleum are one of the factors that influence global pollution due to environment problems such as fine dust and ozone layer destruction. In addition use of energies for automobile making resources to become depleted. To solve this limited oil energy problem by using other energy sources. To the problem using electric energy and green energy as alternative for a solution. Among environment friendly energies this paper studies the possibility of drive service for autonomous vehicles that self-charges using only solar energy and whether they can be used as pollution free and alternative energy for automobiles. Studies was researched based on published literature review, data from ministry of transportation and automobile companies. Also case of electric vehicle and prototype automobile using only solar energy and the theory of near future technologies. Many automakers are using electric cars as alternative energy. Also making efforts to use solar energy as an substitute energy source and as a way to supplement electricity. Results show that there is a potential on operating autonomous vehicle using only solar energy. Furthermore, it will be possible to use automobiles actively, also use and supply solar energy. This paper suggest the possibility of contributing to the future of the automotive industry.

Signaling Effects of Government Support on Investment Attraction of Technology-based Start-ups: An Empirical Study of a Hurdle Model (기술창업기업의 투자유치에 대한 정부지원의 신호효과: 허들모형을 이용한 실증연구)

  • Bong, Kang Ho;Kwon, Jihun;Kim, Kyu-Tae
    • Korean small business review
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    • v.42 no.4
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    • pp.309-326
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    • 2020
  • There often is information asymmetry between start-ups and the investors, which is because start-up companies in the early stages do not have track records. Meanwhile, since the government grants programs go through a fair and the intense competition process, the government grants can provide a more objective information for start-ups in the early stages and perform a signal function that guarantees a company's capabilities and potential. This study confirms the quantitative relationship between government grants and investment attraction by using the hurdler model. We found that, although there is the proportionate relationship between the scale of government grants and that of external funds, more than a certain amount of government grants is required for technology-based start-ups to exceed the stage of attracting their first external funds. Our findings suggest that it is necessary to consider the hurdles structure in the study of signaling theory perspective, as the mechanisms for determining whether or not to attract external funds are different from determining the level of external funds. In addition, differentiated policy support is needed to help early-stage technology start-ups go beyond the threshold of investment attraction-the creation of a 'threshold effect'.