• Management & Information Systems Review
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• v.36 no.3
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• pp.219-237
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• 2017

Looking into the top-five innovative sectors in Korea's manufacturing and service industries, this study empirically analyzes the effect of innovation performance on R&D investment, which is one of the most important strategic decisions for corporate management. In the midst of an uncertain business environment, R&D investment has been regarded as the most important strategic decision making in corporate management related to innovation. Corporate management, however, tend to be reluctant to make sufficient R&D investment due to the risk of an investment failure. Therefore, having R&D investment by offsetting this risk has been deemed as a key task for corporate management. However, prior studies have failed to identify which factors affect companies' strategic decision making on R&D investment. This study is to remedy this weakness of prior study. Relying on path dependency theory at organization-level and dominant logic at individual-level, this study empirically examines the multiple regression model, which sees entrepreneurial orientation as a positive mediator between innovation performance and R&D investment. The results found in the analysis of 242 local companies in the manufacturing and service sectors represent that innovation performance has a direct and positive effect on R&D investment, while it indirectly affects R&D investment through the mediating roles of entrepreneurial orientation. They also revealed that innovation performance had a meaningful impact on entrepreneurial orientation, which is an inclination to seek innovation, led to R&D investment. The founding of this study imply that innovation performance in the past affects innovation strategies in the future, and such a relationship could be strengthened by entrepreneurial orientation as the dominant logic of corporate management.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.19-26
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• 2017

Purpose: The application of density override is very important to minimize dose calculation errors by fiducial markers of metal material in proton treatment plan. However, density override with actual material of the fiducial marker could make problem such as inaccurate target contouring and compensator fabrication. Therefore, we perform density override with surrounding material instead of actual material and we intend to evaluate the usefulness of density override with surrounding material of the fiducial marker by analyzing the dose distribution according to the position, material of the fiducial marker and number of beams. Materials and Method: We supposed that the fiducial marker of gold, steel, titanium is located in 1.5, 2.5, 4.0, 6.0 cm from the proton beam's end of range using water phantom. Treatment plans were created by applying density override with the surrounding material and actual material of the fiducial marker. Also, a liver cancer patient who received proton therapy was selected. We located the fiducial marker of gold, steel, titanium in 0, 1.5, 3.5 cm from the proton beam's end of range and the treatment plans were created by same method with water phantom. Homogeneity Index(HI), Conformity Index(CI) and maximum dose of Organ At Risk(OAR) in Planning Target Volume(PTV) as the evaluation index were compared according to the material, position of the fiducial marker and number of beam. Results: The HI value was more decreased when density override with surrounding material of the fiducial marker was performed comparing with density override with actual material. Especially the HI value was increased when the fiducial marker was located farther from the proton beam's end of the range for a single beam and the fiducial marker's position was closer to isocenter for two or more beams. The CI value was close to 1 and OAR maximum dose was greatly reduced when density override with surrounding material of the fiducial marker was performed comparing with density override with actual material. Conclusion: Density override with surrounding material can be expected to achieve more precise proton therapy than density override with actual material of the fiducial marker and could increase the dose uniformity and target coverage and reduce the dose to surrounding normal tissues for the small fiducial markers used in clinical practice. Most of all, it is desirable to plan the treatment by avoiding the fiducial marker of metal material as much as possible. However, if the fiducial marker have on the beam path, density override of the surrounding material can be expected to achieve more precise proton therapy.

• Asia pacific journal of information systems
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• v.19 no.4
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• pp.101-124
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• 2009

According to Wikipedia, virtual reality (VR) is defined as a technology that allows a user to interact with a computer-simulated environment. Due to a rapid growth in information technology (IT), the cost of virtual reality has been decreasing while the utility of virtual reality advertisements has dramatically increased. Nevertheless, only a few studies have investigated the effects of virtual reality advertisement on consumer behaviors. Therefore, the objective of this study is to empirically examine the effects of virtual reality advertisement. Compared to traditional online advertisements, virtual reality advertisement enables consumers to experience products realistically over the Internet by providing high media richness, interactivity, and telepresence (Suh and Lee, 2005). Advertisements with high media richness facilitate consumers' understanding of advertised products by providing them with a large amount and a high variety of information on the products. Interactivity also provides consumers with a high level of control over the computer-simulated environment in terms of their abilities to adjust the information according to their individual interests and concerns and to be active rather than passive in their engagement with the information (Pimentel and Teixera, 1994). Through high media richness and interactivity, virtual reality advertisements can generate compelling feelings of "telepresence" (Suh and Lee, 2005). Telepresence is a sense of being there in an environment by means of a communication medium (Steuer, 1992). Virtual reality advertisements enable consumers to create a perceptual illusion of being present and highly engaged in a simulated environment, while they are in reality physically present in another place (Biocca, 1997). Based on the characteristics of virtual reality advertisements, a research model has been proposed to explain consumer responses to the virtual reality advertisements. The proposed model includes two dimensions of consumer responses. One dimension is consumers' rational response, which is based on the Information Processing Theory. Based on the Information Processing Theory, product knowledge and perceived risk are selected as antecedents of intention to purchase. The other dimension is emotional response of consumers, which is based on the Attitude-Structure Theory. Based on the Attitude-Structure Theory, arousal, flow, and positive affect are selected as antecedents of intention to purchase. Because it has been criticized to have investigated only one of the two dimensions of consumer response in prior studies, our research model has been built so as to incorporate both dimensions. Based on the Attitude-Structure Theory, we hypothesized the path of consumers' emotional responses to a virtual reality advertisement: (H1) Arousal by the virtual reality advertisement increases flow; (H2) Flow increases positive affect; and (H3) Positive affect increases intension to purchase. In addition, we hypothesized the path of consumers' rational responses to the virtual reality advertisement based on the Information Processing Theory: (H4) Increased product knowledge through the virtual reality advertisement decreases perceived risk; and (H5) Perceived risk decreases intension to purchase. Based on literature of flow, we additionally hypothesized the relationship between flow and product knowledge: (H6) Flow increases product knowledge. To test the hypotheses, we conducted a free simulation experiment [Fromkin and Streufert, 1976] with 300 people. Subjects were asked to use the virtual reality advertisement of a cellular phone on the Internet and then answer questions about the variables. To check whether subjects fully experienced the virtual reality advertisement, they were asked to answer a quiz about the virtual reality advertisement itself. Responses of 26 subjects were dropped because of their incomplete answers. Responses of 274 subjects were used to test the hypotheses. It was found that all of six hypotheses are accepted. In addition, we found that consumers' emotional response has stronger impact on their intention to purchase than their rational response does. This study sheds much light into practical implications for both IS researchers and managers. First of all, while most of previous research has analyzed only one of the customers' rational and emotional responses, we theoretically incorporated and empirically examined both of the two sides. Second, we empirically showed that mediators such as arousal, flow, positive affect, product knowledge, and perceived risk play an important role between virtual reality advertisement and customer's intention to purchase. In addition, the findings of this study can provide a basis of practical strategies for managers. It was found that consumers' emotional response is stronger than their rational response. This result indicates that advertisements using virtual reality should focus on the emotional side, and that virtual reality can be served as an appropriate advertisement tool for fancy products that require their online advertisements to give an impetus to customers' emotion. Finally, even if this study examined the effects of virtual reality advertisement of cellular phone, its findings could be applied to other products that are suited for virtual experience. However, this research has some limitations. We were unable to control different kinds of consumers and different attributes of products on consumers' intention to purchase. It is, therefore, deemed important for future research to control the consumer and product types for more reliable results. In addition to the consumer and product attributes, other variables could affect consumers' intention to purchase. Thus, the future research needs to find ways t control other variables.

• Asia pacific journal of information systems
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• v.20 no.1
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• pp.127-140
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• 2010

The benefit that a consumer derives from the use of a good often depends on the number of other consumers purchasing the same goods or other compatible items. This property, which is known as network externality, is significant in many IT related industries. Over the past few decades, network externalities have been recognized in the context of physical networks such as the telephone and railroad industries. Today, as many products are provided as a form of system that consists of compatible components, the appreciation of network externality is becoming increasingly important. Network externalities have been extensively studied among economists who have been seeking to explain new phenomena resulting from rapid advancements in ICT (Information and Communication Technology). As a result of these efforts, a new body of theories for 'New Economy' has been proposed. The theoretical bottom-line argument of such theories is that technologies subject to network effects exhibit multiple equilibriums and will finally lock into a monopoly with one standard cornering the entire market. They emphasize that such "tippiness" is a typical characteristic in such networked markets, describing that multiple incompatible technologies rarely coexist and that the switch to a single, leading standard occurs suddenly. Moreover, it is argued that this standardization process is path dependent, and the ultimate outcome is unpredictable. With incomplete information about other actors' preferences, there can be excess inertia, as consumers only moderately favor the change, and hence are themselves insufficiently motivated to start the bandwagon rolling, but would get on it once it did start to roll. This startup problem can prevent the adoption of any standard at all, even if it is preferred by everyone. Conversely, excess momentum is another possible outcome, for example, if a sponsoring firm uses low prices during early periods of diffusion. The aim of this paper is to analyze the dynamics of the adoption process in markets exhibiting network effects by focusing on two factors; switching and agent heterogeneity. Switching is an important factor that should be considered in analyzing the adoption process. An agent's switching invokes switching by other adopters, which brings about a positive feedback process that can significantly complicate the adoption process. Agent heterogeneity also plays a important role in shaping the early development of the adoption process, which has a significant impact on the later development of the process. The effects of these two factors are analyzed by developing an agent-based simulation model. ABM is a computer-based simulation methodology that can offer many advantages over traditional analytical approaches. The model is designed such that agents have diverse preferences regarding technology and are allowed to switch their previous choice. The simulation results showed that the adoption processes in a market exhibiting networks effects are significantly affected by the distribution of agents and the occurrence of switching. In particular, it is found that both weak heterogeneity and strong network effects cause agents to start to switch early and this plays a role of expediting the emergence of 'lock-in.' When network effects are strong, agents are easily affected by changes in early market shares. This causes agents to switch earlier and in turn speeds up the market's tipping. The same effect is found in the case of highly homogeneous agents. When agents are highly homogeneous, the market starts to tip toward one technology rapidly, and its choice is not always consistent with the populations' initial inclination. Increased volatility and faster lock-in increase the possibility that the market will reach an unexpected outcome. The primary contribution of this study is the elucidation of the role of parameters characterizing the market in the development of the lock-in process, and identification of conditions where such unexpected outcomes happen.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.737-760
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• 2022

For the geological disposal of high-level radioactive wastes (HLW), an understanding of deep subsurface environment is essential through geological, hydrogeological, geochemical, and geotechnical investigations. Although South Korea plans the geological disposal of HLW, only a few studies have been conducted for characterizing the geochemistry of deep subsurface environment. To guide the hydrogeochemical research for selecting suitable repository sites, this study overviewed the status and trends in hydrogeochemical characterization of deep groundwater for the deep geological disposal of HLW in developed countries. As a result of examining the selection process of geological disposal sites in 8 countries including USA, Canada, Finland, Sweden, France, Japan, Germany, and Switzerland, the following geochemical parameters were needed for the geochemical characterization of deep subsurface environment: major and minor elements and isotopes (e.g., ³⁴S and ¹⁸O of SO₄^2-, ¹³C and ¹⁴C of DIC, ²H and ¹⁸O of water) of both groundwater and pore water (in aquitard), fracture-filling minerals, organic materials, colloids, and oxidation-reduction indicators (e.g., Eh, Fe²⁺/Fe³⁺, H₂S/SO₄^2-, NH₄⁺/NO₃^-). A suitable repository was selected based on the integrated interpretation of these geochemical data from deep subsurface. In South Korea, hydrochemical types and evolutionary patterns of deep groundwater were identified using artificial neural networks (e.g., Self-Organizing Map), and the impact of shallow groundwater mixing was evaluated based on multivariate statistics (e.g., M3 modeling). The relationship between fracture-filling minerals and groundwater chemistry also has been investigated through a reaction-path modeling. However, these previous studies in South Korea had been conducted without some important geochemical data including isotopes, oxidationreduction indicators and DOC, mainly due to the lack of available data. Therefore, a detailed geochemical investigation is required over the country to collect these hydrochemical data to select a geological disposal site based on scientific evidence.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.14-23
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• 1998

The present study investigates numerically particle laden flow through compressor cascade. In general, a lot of turbine engines are affected by various particles which are suspending in the atmosphere. Especially in the case of aircraft aviating in volcanic, industrial and desert region including many particles, each components of engine system are damaged severely. That damage modes are erosion of compressor binding and rotor path components, partial or total blockage of cooling passage and engine control system degradation.. Initial damages can not be serious but cumulation of damages influences on safety of aircraft control and economical maintenance cost of engine system can be increased. When dust, materials and volcanic particles in the atmosphere flow in the compressor, it is necessary to predict damaged and deposited region of compressor blades. To the various flow inlet angle, predictions of particles trajectory in compressor cascade by Lagrangian method are presented and impulses by impaction of particles at blade surface are calculated. By the definition of particle deposition efficiency, characteristics of particles impact are considered quantitatively. With these prediction and experimental data, erosion rates are predicted for two materials - ceramic, soft metal - on compressor blade surface. Improvements like coating of blade surface could be found, by above prediction.

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.73-86
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• 2017

The purpose of this study was to investigate the influence of consumers' shopping value(SV), ease of use(EOU), and usefulness(U) on their purchase intention(PI) in mobile shopping mall. Path hypotheses in structural equation model which was constructed for this purpose were verified. In addition, the research model was analyzed according to the groups classified by the level of purchase experience in mobile shopping mall. The survey was limited to the respondents in their 20s and 30s living in Seoul and other metropolitan areas who had purchased fashion products in mobile shopping mall. 411 useful data collected from on-line survey were analyzed by descriptive statistics, exploratory factor analysis, confirmatory factor analysis, reliability analysis, and pearson's correlation analysis using SPSS 21 and AMOS 19. The results of verifying the hypotheses were as follows: First, SV was composed of two factors which included hedonic shopping value(HSV) and utilitarian shopping value(USV). Second, the research model was verified as an acceptable model in explaining the influence of consumers' SV, EOU, and U on PI. Third, seven hypotheses among nine hypotheses were accepted in high purchasers. HSV did not have a significant influence on PI, and EOU did not affect PI significantly. Fourth, five hypotheses were accepted in light purchasers. HSV affected U significantly while USV had a significant impact on EOU and PI. EOU affected U, and U affected PI significantly. In conclusion, USV was proven to be the factor affecting PI directly as well as indirectly. Eou and U also had a significant influnce on PI in mobile fashion shopping. These results will provide mobile marketers with the differentiated strategies to make consumers lead to mobile purchase.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.233-245
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• 2020

This study aims to investigate the relationship between positive psychological capital and entrepreneurial intention among middle-aged and elderly individuals who are interested in starting their own business by focusing on the mediating effect of risk sensitivity and the moderating effect of asset status. To accomplish the study's objective, a questionnaire was administered to approximately 250 middle-aged and elderly people working in Seoul from December 1 to December 31, 2019. Collected data were analyzed using SPSS 26.0. Specifically, frequency analysis and descriptive statistics were conducted, and reliability of the constructs was assessed. Factor analysis was used to measure the goodness of fit of the model developed. Finally, a structural equation model was established, and analysis was conducted on the test of the hypotheses about the mediating, moderating, and adjusting effects using the AMOS statistical package. The results revealed that positive psychological capital had a positive impact on risk sensitivity, and the path analysis of self-efficacy and entrepreneurial intention as well as resilience and entrepreneurial intention showed results of 0.042 and 0.026, respectively, supporting mediating effects. In the causal relationship between positive psychological capital and entrepreneurial intention, asset status acted as a moderator given that the chi square difference between the models was 7.096. Thus, the findings provide implications for comprehensive training programs to boost positive psychological capital and asset status in middle-aged and elderly individuals who are preparing to establish their own business. Further studies are needed to cover broader geographic areas and compare/analyze other variables associated with business startups.

• Economic and Environmental Geology
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• v.34 no.5
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• pp.461-470
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• 2001

The Shihung mine was restored in the early 90's after abandonment for 20 yews since 1973. Although disposed mine tailings were removed and the site was replaced by an incineration plant, still some residual mine tailings remain in the places including the old mine tailing ditposal area and the adjacent agricultural area. These residual mine tailings are prone to impose an adverse impact on the soil and groundwater and needs investigation for the potential contamination. Mine tailing samples were collected from the old tailing disposal area and the iii paddy. The porewater from the mine tailing were extracted and analysed to investigate chemical changes along the reaction path. Batch leaching tests were also carried out in the laboratory to find any supporting evidence found in the field analysis. Evidence of elemental leaching was confirmed both by the mine tailing and the porewater chemistry in them. The element concentrations of Cu, Cd, Pb, Zn in the porewater exceed the standard for drinking water of Korean government and US EPA. Leaching of heavy metals from the mine tailing seem to be responsible for the contamination. In batch leaching test. heavy metals were either continuous1y released or declined rapidly. Combining the information with porewater variation with depths and the geochemical meodeling results, most of elements are controlled by dissolution and/or precipitation processes, with some solubility controlling solid phases (Cu, Pb, Fe and Zn). Batch leaching test conducted at fixed pH 4 showed much higher releases for the heavy metals up to 400 times (Zn) and this area is becoming more vulnerable to soil and groundwater pollution as precipitation pH shifts to acidic condition.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.7-18
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• 2012

So many researchers have been interested in key success factors of technological start-ups. However, even previous studies have focussed on key success factors, as their findings have not been consistent. The purpose of this study is to investigate the determinants of technological start-ups' performance. The first aim of this study is intended to explores impact of entrepreneurs' characteristics, technological capabilities and network on firm performance. The second aim is to examine the causal relationships among latent variables with firm performance and with the use of path analysis. For this study, information has been gathered through surveys from entrepreneurs of 701 Korean technological start-up companies. As for analysis of the data, SPSS 18.0 OK for Windows and AMOS 4.0 were used for testing of hypothesis. Results of the hypothesis testing are summarized as follows: First, it was found that entrepreneurs' characteristics, technological capabilities and network had statistically significant influence on firm performance. Second, entrepreneurs' characteristics had significant influence on technological capabilities and network. Third, network did not have significant influence on technological capabilities. The major contributions of this study are (1) identifying the determinants on firm performance of technology-based start-ups by means of structural equation model, (2) verifying effects on firm performance of technology-based start-ups by the variables.