• Proceedings of the KOR-KST Conference
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• 1995.12a
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• pp.45-73
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• 1995

The current paper presents a system dynamics model which can generate the land use anq transportation system performance simultaneously is proposed. The model system consists of 7 submodels (population, migration of population, household, job growth-employment-land availability, housing development, travel demand, and traffic congestion level), and each of them is designed based on the causality functions and feedback loop structure between a large number of physical, socio-economic, and policy variables. The important advantages of the system dynamics model are as follows. First, the model can address the complex interactions between land use and transportation system performance dynamically. Therefore, it can be an effective tool for evaluating the time-by-time effect of a policy over time horizons. Secondly, the system dynamics model is not relied on the assumption of equilibrium state of urban systems as in conventional models since it determines the state of model components directly through dynamic system simulation. Thirdly, the system dynamics model is very flexible in reflecting new features, such as a policy, a new phenomenon which has not existed in the past, a special event, or a useful concept from other methodology, since it consists of a lots of separated equations. In Chapter I, II, and III, overall approach and structure of the model system are discussed with causal-loop diagrams and major equations. In Chapter V _, the performance of the developed model is applied to the analysis of the impact of highway capacity expansion on land use for the area of Montgomery County, MD. The year-by-year impacts of highway capacity expansion on congestion level and land use are analyzed with some possible scenarios for the highway capacity expansion. This is a first comprehensive attempt to use dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions. The model structure is not very elaborate mainly due to the problem of the availability of behavioral data, but the model performance results indicate that the proposed approach can be a promising one in dealing comprehensively with complicated urban land use/transportation system.

• Asia pacific journal of information systems
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• v.23 no.4
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• pp.103-128
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• 2013

When a consumer needs a product or service and multiple sellers are available online, the process of selecting a seller to buy online from is complex since the process involves many behavioral dimensions that have to be taken into account. As a part of this selection process, consumers may set minimum trust expectation that can be used to screen out less trustworthy sellers. In the previous research, the level of consumers' trust expectation has been anchored on two important factors: product involvement and perceived risk. Product involvement refers to the extent to which a consumer perceives a specific product important. Thus, the higher product involvement may result in the higher trust expectation in sellers. On the other hand, other related studies found that when consumers perceived a higher level of risk (e.g., credit card fraud risk), they set higher trust expectation as well. While abundant research exists addressing the relationship between product involvement and perceived risk, little attention has been paid to the integrative view of the link between the two constructs and their impacts on the trust expectation. The present paper is a step toward filling this research gap. The purpose of this paper is to understand the process by which a consumer chooses an online merchant by examining the relationships among product involvement, perceived risk, trust expectation, and intention to buy from an e-tailer. We specifically focus on the mediating role of perceived risk in the relationships between enduring product involvement and the trust expectation. That is, we question whether product involvement affects the trust expectation directly without mediation or indirectly mediated by perceived risk. The research model with four hypotheses was initially tested using data gathered from 635 respondents through an online survey method. The structural equation modeling technique with partial least square was used to validate the instrument and the proposed model. The results showed that three out of the four hypotheses formulated were supported. First, we found that the intention to buy from a digital storefront is positively and significantly influenced by the trust expectation, providing support for H4 (trust expectation ${\rightarrow}$ purchase intention). Second, perceived risk was found to be a strong predictor of trust expectation, supporting H2 as well (perceived risk ${\rightarrow}$ trust expectation). Third, we did not find any evidence of direct influence of product involvement, which caused H3 to be rejected (product involvement ${\rightarrow}$ trust expectation). Finally, we found significant positive relationship between product involvement and perceived risk (H1: product involvement ${\rightarrow}$ perceived risk), which suggests that the possibility of complete mediation of perceived risk in the relationship between enduring product involvement and the trust expectation. As a result, we conducted an additional test for the mediation effect by comparing the original model with the revised model without the mediator variable of perceived risk. Indeed, we found that there exists a strong influence of product involvement on the trust expectation (by intentionally eliminating the variable of perceived risk) that was suppressed (i.e., mediated) by the perceived risk in the original model. The Sobel test statistically confirmed the complete mediation effect. Results of this study offer the following key findings. First, enduring product involvement is positively related to perceived risk, implying that the higher a consumer is enduringly involved with a given product, the greater risk he or she is likely to perceive with regards to the online purchase of the product. Second, perceived risk is positively related to trust expectation. A consumer with great risk perceptions concerning the online purchase is likely to buy from a highly trustworthy online merchant, thereby mitigating potential risks. Finally, product involvement was found to have no direct influence on trust expectation, but the relationship between the two constructs was indirect and mediated by the perceived risk. This is perhaps an important theoretical integration of two separate streams of literature on product involvement and perceived risk. The present research also provides useful implications for practitioners as well as academicians. First, one implication for practicing managers in online retail stores is that they should invest in reducing the perceived risk of consumers in order to lower down the trust expectation and thus increasing the consumer's intention to purchase products or services. Second, an academic implication is that perceived risk mediates the relationship between enduring product involvement and trust expectation. Further research is needed to elaborate the theoretical relationships among the constructs under consideration.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.503-519
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• 2014

This study was conducted to investigate ginger growth and its nutrient uptake depending on changes of soil properties as affected by applications of green manure crop and/or charcoal in continuous cropping system. The green manure crops applied were barley and hairy vetch, and charcoal was additionally treated in selected plots as a soil conditioner. Experimental plots were prepared as Plot 1 (control), Plot 2 (barley of 8kg $10a^{-1}$), Plot 3 (hairy vetch of 12kg $10a^{-1}$), Plot 4 (charcoal of 1,000kg $10a^{-1}$ and barley 8kg $10a^{-1}$), and Plot 5 (charcoal of 1,000kg $10a^{-1}$ and hairy vetch of 12kg $10a^{-1}$) with two different soil conditions (high clay content, HCC and low clay content, LCC). When comparing selected chemical properties of soils before and after cultivating ginger plant, soil pH decreased from 6.9~8.1 to 6.8~7.6, and electrical conductivity (EC) also declined from $0.45{\sim}1.25dSm^{-1}$ to $0.30{\sim}0.61dSm^{-1}$. However, the content of soil organic matter (SOM) and total nitrogen (T-N) increased. Thus, the soil chemical properties were improved with the applications of green manures and charcoal. Also, macro- and micro-nutrient contents of ginger plants in the different plots were various between normal and diseased plants grown in soils with HCC and LCC. In particular, the concentration of manganese (Mn) was 3~4 folds higher in the diseased plant than in the normal plants. Ginger growth status and yield was relatively improved with the applications of green manures and charcoal as comparing with control plot. Especially in the Plot 4 with LCC, the ginger plant was not infected by root-rot disease.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.195-205
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• 2013

Excessive input of organic matters from fish cage farming has been considered as one of the major factors disturbing benthic ecosystem, especially in semi-enclosed coastal waters. Recently offshore aquaculture in the vicinity of Jeju-do has been introduced to minimize that kind of negative impact. This study was conducted to investigate the ecological impacts of offshore aquaculture on the macrobenthic polychaete communities. A total of ten sampling works were carried out for 28 months, spanning from 10 days after starting giving feed to 3 months after stopping giving feed. During the study period, mean current velocity was quite strong with the range of 50 cm/s to 70 cm/s. TOC of surface sediment was constantly low. Significant changes in polychaete community were detected just three months after starting giving feed, which were the increase of the number of species and density at all stations. Up to 18 months after the start of farming, the amount of feed provided played an important role in the fluctuation of the number of species and density, especially at 0 m and 10 m stations. After reducing the amount of feed provided, dominance of some opportunistic species within 10 m distance from fish cages still lasted to the end of aquaculture. However, opportunistic species disappeared 3 months after the end of farming, which indicated the sign of recovery from the disturbance. From these results, the amount of food input and the period of cultivation were critical factors disturbing polychaete community and ensuing changes in this offshore and oligotrophic waters as well. In addition, study on the changes of polychaete community structure before and after fish farming showed more detailed changes in benthic ecological state than geochemical approach did.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.149-155
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• 2015

Tooth implant is located in oral cavity and affects neck, skull base, and facail image. These magnetic inhomogeneities are usually frequency encoding direction which cause artifacts due to change of signal strength and geometric distortion. First, to evaluate signal to noise ratio (SNR) of magnetic resonance image caused by tooth implant this study uses meat phantom which is similar to human body and is consisted with fat, muscle, and water to measure signal to noise ratio. Second, signal to noise ratio by using custom-made fixed phantom is measured, and then signal to noise ratio size of different tooth implant types is compared and analyzed. The measured signal to noise ratio values of Brushite, HSA, Metal, and RBM for meat phantom were 2.76, 2.22, 1.88, and 1.57 on T1 SE, 1.88, 1.78, 1.65, and 1.79 on T2 FLAIR, 2.28, 2.25, 2.88, and 2.05 on T2 FSE, and 2.74, 1.94, 1.67, and 1.48 on T2 GRE. The measured signal to noise ratio values of Brushite, HSA, Metal, and RBM for fixed water phantom were 1.2, 1.06, 1.12, and 1.22 on DWI, 1.93, 1.87, 1.93, and 2.06 T1 SE, 1.83, 1.76, 1.82, and 1.92 on T2 FLAIR, 1.85, 1.79, 7.86, and 1.97 on T2 FSE, and 1.97, 1.93, 1.99, and 2.06 on T2 GRE. By considering through the results, patients and dentists need to consider some impacts from testing many aspects although their main purpose of having tooth implants is a dental restoration. Moreover, depending on the tooth implant characteristics of individual patients this study results can be used as baseline data when choosing test protocol.

• Korean Journal of Comparative Education
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• v.27 no.1
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• pp.145-169
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• 2017

The purpose of this study is to investigate the influences of educational policy transfer on transitional countries by analyzing the impacts of the Bologna Process on the educational systems of former socialist countries in Europe including Russia, Ukraine, and Hungary. For this purpose, documents published by European Union and its associated educational institutions, as well as academic institutions and scholars were analyzed to evaluate the changes made not only in the systemic level but also institutional and personal levels. The Bologna Process, instigated by the rise of knowledge economy and globalization, is purported to be the most influential educational reform conducted by the member countries since the formation of EU. However, unlike its original intentions to promote the voluntary participation of universities and students, the Bologna Process strengthened the structure of centralized bureaucracy in the educational systems, and restricted the freedom of professors, since most of the universities in these countries relied on governments for their funding. This indicates that in analyzing the influences of educational policy transfer in transitional countries, it is important to analyze the roles and motivations of actors participating in the decision-making processes. Moreover, Bologna Process reforms, made under the direction and control of government, were often turned into cases in which administrators hurriedly implement new policies against the will of faculty members and students, thus impeding the efficient localization of the reforms. This case, thus, implies that while educational reforms driven by policy transfer can change external systems and policies of universities, the fundamental reforms in the minds of faculty and inner workings of organization can only come about after a careful consideration of the societal and cultural values embedded within society.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.5
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• pp.79-92
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• 2019

When asked about the success factors of successful entrepreneurs and celebrities, he says he was lucky. The remarkable fact is that the attitude about luck is different. However, despite the fact that the belief that we believe is lucky is actually a dominant concept, there has not been much scientific verification of luck. In this study, we saw good luck not being determined randomly by the external environment, but by being able to control luck through the internal attributes of individuals. This study is significant that we have empirically elucidated what kind of efforts have gained good luck, whereas previous research has largely ended in vague logic where luck ends up with an internal locus of control among internal entrepreneurial qualities and efforts can make a successful entrepreneur. We introduced the concept of good luck belief to avoid confirmation bias, which is, to interpret my experience in a direction that matches what I want to believe, and used a good luck belief questionnaire in previous studies and tried to verify that those who have a good belief can increase entrepreneurial opportunity capability through planned happenstance skills. The reason for choosing the entrepreneurial opportunity capacity as a dependent variable was based on the conventional research, that is, the process of recognizing and exploiting the entrepreneurial opportunity is an important part of the entrepreneurship research For empirical research, we conducted a questionnaire survey of a total of 332 people, and the results of the analysis turned out that the belief of good luck has all the positive impacts of planned happenstance skills' sub-factors: curiosity, patience, flexibility, optimism and risk tolerance. Second, we have shown that only the perseverance, optimism, and risk tolerance of planned happenstance skills' sub-factors have a positive impact on this opportunity capability. Thirdly, it was possible to judge that the sub-factors of planned happenstance skills, patience, optimism, and risk tolerance, had a meditating effect between belief in luck and entrepreneurial opportunity capability. This study is highly significant in logically elucidating that people in charge of business incubation and education can get the specific direction when planning a training program for successful entrepreneur to further enhance the entrepreneurial opportunity ability, which is an important ability for the entrepreneur's success.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.438-446
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• 2019

The interest in mini watermelon (Citrullus lanatus) with small fruits weighing 2-3 kg has increased by the increasing trend in one-person households and consequent tendency to consume small meals. Watermelon grafting onto cucurbit rootstocks is a very effective way to control soil-borne diseases, such as Fusarium wilt; however, this practice negatively impacts the fruit quality. This study was conducted to investigate the growth, fruit set, and fruit quality of mini watermelon grafted onto wild watermelon accessions (Citrullus spp.) resistant to Fusarium wilt. Five watermelon accessions (Galactica, IT 208441, PI 482322, PI 500303, and PI 593358) were evaluated as rootstocks for the mini watermelon "Ministar". Non-grafted "Ministar" and "Ministar" grafted onto "Shintozwa" (Cucurbita maxima D. C. moschata D.) or "Bullojangsaeng" (Lagenaria leucantha) were used as controls. The roots of the transplants grafted onto "PI 593358" and "Shintozwa" weighed more than those on other rootstocks. Additionally, the transplants on "PI 593358" showed better growth and fruit set in the field than the other transplants. However, the total soluble solid contents and fruit quality indices of the transplants on "PI 593358" and "Shintozwa" were lower, whereas the total fruit quality index of those on "PI 482322" was higher. Thus, the wild watermelon accessions tested can potentially be used as basic germplasm for developing watermelon rootstocks instead of cucurbit rootstocks. The most promising accession for this purpose was found to be "PI 482322".

• Journal of Korea Port Economic Association
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• v.34 no.4
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• pp.141-160
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• 2018

In this paper, to analyze the perception and response strategy of Korean ship owners on Global Sulphur Cap 2020, examined the IMO environmental regulation status focusing on MARPOL Annex VI regulation about air pollution prevention, technological measures to reduce SOx emission, shipping industry and management status of Korean ship owners. First of all, the questionnaire was conducted for Korean ship owners after selecting the evaluation factors. The purpose of this study was to investigate the difference of the perception and response strategy of Korean ship owners by corporation size and main vessel type using frequency and cross analysis. It is confirmed that various researches on SOx emission reduction have been carried out from various points of view at home and abroad. In this study, existing studies related to technical factors for regulatory response and economics analysis were examined and evaluation factors were selected. As a result of analysis, it is found that large-sized shipping companies are more prepared for regulatory response than small and medium-sized bulk carrier owners. There were similar perception and the direction of response strategy about the impacts by corporation size and main vessel type. In about two years to be implemented in 2020, It is necessary to find an appropriate response strategy based on the support policy of the government and related organizations and the systematic analysis of the ship owners. Through this study, although the difference between the perception and response strategy of the ship owners by corporation size and main vessel type was understood, it was found that there were limitations on specific response strategy and corporate data collection. In future research, we should overcome the limitations of this study and conduct an in-depth study.

• Korea journal of population studies
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• v.11 no.1
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• pp.204-229
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• 1988

This paper documents and discusses trends and differentials in youth's participation in the labor force and employment. Youth in this study is defined asthe young aged 15-29. Youth passes through a series of life-course transitions,which include school completion own family formation(marriage and childbirth) .mandatory service in the army (by males) , and their economic activities are affectedby those life-course events. Accordingly we show how and to what extent youth'slabor force participation and employment varies with age and how the age patternhas changed over time.Throughout the 1980's and 1990's, youth's labor force participation showeddifferent trends by age group Labor fDrce participation rate of the 15-19 agedsteeply decreased, while that of the 25-29 steadily increased during the twodecades, the rate fsr the 20-24 aged showing not much variation. The former is dueto the increased rate of school enrollment among the age group, while the lattercould be attributed, in part, to the young women s increased and more steadyparticipation in the labor force over time.While labor force participation could be considered as a result of one's choicesand preferences, employment opportunities are more or less restricted by labormarket structure and institutions . This study documents how the structuralconstraints have interacted with individual and group attributes to differentiateemployment opportunities between individuals (educational background) and groups(especially sex diffrences) . One of the most salient feature of youth's em[ploymentstructure is the recent high unemployment rate of the college graduates. We discusshow that is related to the'credential society'in which one's educational credentials and it's social status play major role in determining who gets what in terms of job opportunities. Also is discussed the discordance between school and labor marketsupply and demand system, which is apparent in the prolonged oversupply of thecollege graduates, which is due to the consistently high rate of college entranceobserved since the early 1980's. Theoretically the job market for college graduates isviewed not as the'neoclassical'wage competition market but as job competition market in which one's (good) job opportunity is determined by one s position in thejob queue, which is in turn heavily dependent on from which college one get shis/her college degree as well as one's sex.