• Environmental and Resource Economics Review
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• v.25 no.2
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• pp.199-228
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• 2016

This study investigates the effects of economic factors and forest environments on rural residential area development in seven north central states of the U.S. by focusing on the relative importance of not only economic factors but also forest environments by forest type as core drivers of residential development. An empirical model of locations and magnitudes of population changes since 1950 in the north central region is first constructed, and then a panel model with fixed effects for counties is used to explain population growth by age group over time at the county level. Then a set of three equations is estimated for three major age groups, and a cross-sectional model is estimated for the last time period that regresses county-level environmental amenity variables on fixed effects coefficients for counties. Finally, an equation explaining changes in rural housing density is estimated. The results imply that immigrant age is a key factor influencing the choice of the place of residence and that the effects of environmental amenity factors on population growth and subsequent housing development in a county vary according to the age group.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.35-46
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• 2008

Soil moisture is one of the important components in hydrological processes and also controls the subsurface flow mechanism at a hillslope scale. In this study, time series of soil moisture were measured at a hillslope located in Gwangneung National Arboretum, Korea using a multiplex Time Domain Reflectometry(TDR) system measuring soil moisture with bi-hour interval. The Box-Jenkins transfer function and noise model was used to estimate spatial distributions of soil moisture histories between May and September, 2007. Rainfall was used as an input parameter and soil moisture at 10 cm depth was used as an output parameter in the model. The modeling process consisted of a series of procedures(e.g., data pretreatment, model identification, parameter estimation, and diagnostic checking of selected models), and the relationship between soil moisture and rainfall was assessed. The results indicated that the patterns of soil moisture at different locations and slopes along the hillslope were similar with those of rainfall during the measurment period. However, the spatial distribution of soil moisture was not associated with the slope of the monitored location. This implies that the variability of the soil moisture was determined more by rainfall than by the slope of the site. Due to the influence of vegetation activity on soil moisture flow in spring, the soil moisture prediction in spring showed higher variability and complexity than that in early autumn did. This indicates that vegetation activity is an important factor explaining the patterns of soil moisture for an upland forested hillslope.

• Journal of Korean Society of Transportation
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• v.31 no.3
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• pp.33-44
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• 2013

Personal Rapid Transit(PRT) has emerged as a promising transportation mode for transit-oriented sustainable communities. In this study, an alternative design of questionnaire survey is proposed in order to capture traveler's perception of an unexperienced transportation mode. This study aims at predicting the mode choice diversion behavior of potential PRT users who do not have experience of using it previously, considering their willingness-to-pay. The proposed model was applied to predict an aggregate forecast of PRT patronage for the city of Songdo where PRT is considered to be constructed. For validation of the proposed model, the price elasticity of PRT demand was analyzed, compared with existing models. The analysis results suggest that the proposed design of questionnaire survey is able to capture respondents' attitude and perception to unexperienced transportation mode in an effective manner. Also, they show that the proposed diversion rate model is more realistic than existing models in explaining the effects of users' willingness-to-pay for predicting PRT patronage.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.145-157
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• 2004

Microscopic freeway simulation models project the uncertain values of performance measures for subject traffic conditions by explaining drivers' driving behavior with lane changing and car-following models. However, the existing lane changing models are limited to gap acceptance oriented passive behavior of drivers and not able to capture more-or-less aggressive driving behavior(e.g. cut-in lane changing) ordinarily obseved in field. This paper suggests the definition of cut-inlane changing and presents its characteristics based on the findings from two different freeway on- and off-ramp sections. In addition, this paper proposes a new lane changing model capable of handling both passive and active drivers' driving behavior for better performance of simulations. The proposed lane changing model was tested with Hanyang Simulatin (HYTSIM), a microscopic freeway simulation program developed for this study. The HYTSIM simulation results reflecting the performance of the proposed lane changing model were compared against the field data. The test results showed that the distribution of gaps collected when vehicles change lanes were statistically identical to the field data at 95% confidence level.

• Journal of Distribution Research
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• v.7 no.1
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• pp.105-127
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• 2002

This paper presents an analysis of how the business models of organizations are getting transformed in the Marketspace created by the Internet. We use a research model comprising the transformation scores of four Ps(Product, Price, Promotion, and Place) as dependent variables and three dimensions, Demographics, Technology, and Community elements on the Websites, as explaining variables about the Cyber Transformation of the 4Ps. While most existing literatures have focused on Website's technology, our research model includes 22 five-point-scale items; 10 Demographics /Technology items and 12 Community items. To measure the 4P's transformation scores, the authors selected 14 workable items from the Marketspace Model by Dutta, Kwan, & Segev(1997). A sample of 123 shopping mall Websites comprising three categories(grocery, jewelry/accessory, and cosmetics) from the 100hot.co.kr list are evaluated and the data is analyzed by SPSSWIN 8.0 version. The result shows that there are five significant factors, Technology, Interaction, Connectedness, Business Features, and Domain, while the average transformation scores of 4Ps are at very low level. The factor scores are used in regression analysis for each P. Two factors, Technology and Interaction are influencing all four Ps; Connectedness is influencing only two, Product and Place. Organizations must not simply take their existing business models. They have to adopt the Technology items(navigation, logo, e-mail, guide, graphics) and to facilitate the Interaction items(consulting, number/quality of bulletin boards, participation, offline events) and Connectedness(club activation, contents, partner/site link, entertainment contents) in order to get transformed in the Marketspace successfully in the near future.

• Economic Analysis
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• v.24 no.3
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• pp.1-36
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• 2018

When it comes to explaining the relationship between inventory investment and business fluctuations, the production smoothing theory and the stock-out avoidance theory take contradictory stances. Decision-making related to inventory investments of corporations is thought to be influenced by both motives, but the relative sizes or directions of their respective influences can differ depending upon the phase of the business cycle. Against this backdrop, this paper differs from existing studies in that it theoretically tests the relative significances of the production smoothing and stock-out avoidance motives in the inventory investment dynamics, while placing its analytical focus on determining the existence and patterns of the asymmetric dynamics of inventory investment over the business cycle phases. To this end this paper sets up a non-linear model that is expanded from the existing linear inventory investment model, and checks whether its predictive power is better than that of the existing model. The results of analysis confirm the nature of the asymmetric dynamics of inventory investment over the business cycle phases. A stock-out avoidance motive appears but there is no significant production smoothing motive in boom times. In downturns, in contrast, the stock-out avoidance motive is insignificant, but a quality of asymmetric dynamics in which changes in inventory cause the deepening of recessions, due to the non-convexity of production costs proposed by Ramey (1991), is detected. This paper confirms that a model considering the asymmetric dynamics of inventory investment can have better predictive power than one that does not consider it, through within-sample and out-of-sample predictions and various predictive power tests. These research results are expected to be useful for economic forecasting, through their enhancement of the understandings of the inventory investment dynamics and of the nature of its business cycle destabilization.

• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.37-49
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• 2007

The purpose of this study was to classify the logical forms of scientific explanations provided by teachers in secondary earth science classrooms, to examine the characteristics of the scientific explanations in different forms, and to identify the roles of the teacher and students in discursive practices for scientific explanations. Data came from the earth science teachers who participated in overseas teacher in-service programs in the years 2003 and 2004. A total of 18 video-taped lessons and their verbatim transcriptions were analyzed. The result showed that deductive-nomological explanations occurred most frequently in earth science classrooms and that the deductive-nomological model was well-suited to those problems for which there existed firmly established scientific laws or principles to construct scientific explanations. However, abductive explanations were presented when the classes dealt with retrodictive tasks of earth science. The statistical-probabilistic and statistical-relevance models were also employed in explaining weather proverbs and unusual changes of weather, respectively. Most of the scientific explanations were completed through the teachers' monologic utterances, and students assumed passive roles in discursive practices for developing scientific explanations. Implications for science lessons and science education research were discussed.

• Journal of Technology Innovation
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• v.19 no.1
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• pp.79-109
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• 2011

In his highly cited book, Innovator's Dilemma (1997), Christensen introduced a notion of disruptive technology that is based on the observations from disk-drive industry and used it as an explanatory variable through which new entrants outperform incumbents in the industry. In explaining his later observations of disruptive innovations in other industries, however, his early theory based on disruptive technology has been applied to all cases without careful distinction between the notions of technology and business model (Markides, 2006). Furthermore, it has been criticized that his model suffers from lack of enough explanatory power and other important factors that are necessary to fully explain the observed phenomena in various cases (Danneels, 2004). Motivated by the critics in literature, the current study carefully distinguishes between innovation of technology and innovation of business model in the process of disruptive innovation, and apply our framework to the case of internet shopping mall business. Our study yields two main results. First, the internet-related business model which Christensen argued as an example of disruptive innovation is accomplished through two distinctive and separable growth phases: a period of technology growth and a period of business model growth. Second, in the process of disruptive innovation, the notion of enabling technology plays an important bridging role that connects core technology and business model. Furthermore, we confirm that the success of business model innovation depends on the degree of maturity of the enabling technologies. In conclusion, Christensen's notion of disruptive innovation can be further detailed in terms of technology innovation and business model innovation, and if there exist enabling technologies, the chance of success of the business model is higher when the enabling technology is matured rather than when the core technology is merely acknowledged as a disruptive technology.

• Research in Community and Public Health Nursing
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• v.8 no.2
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• pp.277-288
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• 1997

The purpose of this study is to identify the behavioral subsystems of the obese adult and contribute to the utility of Johnson's Behavioral System Model. The subjects were 167 obese adults in out-patients clinics of 2 hospitals and health clinics for 4 companies. These data were collected by a structured questionnaire with 52 items from July 1 to Sep. 30, 1995. The instrument used for this study was modified from the DBSM -self reporting instrument (1983) and Grubbs(1980)'s. The reliability of this method was cronbach's ${\alpha}$=.8476 and the construct validity of it was accepted by using a factor analysis. These data were analyzed by frequency, percentage, mean, standard deviation, factor analysis, pearson's correlation coefficient, Kruskal-Wallis with an SPSS PC+ Program. The results of this study were as follows: 1. The 9 behavioral subsystems of the obese were indentified : sex-related, attachment-affiliative I(social), dependency, ingestive, eliminative, restorative, aggressive-protective, attachment-affiliative and II (familial), an achievement behavioral subsystem. 2. Out of 9 subsystems, the highest significant positive correlation between dependency and acheivement subsystem was found(r=.5357, p<.01), The next, attachment-affiliative I and attachment-affiliative II subsystem was correlated significantly (r=.4526, p<.01). Significant positive correlations among sex-related, achivement, attachment-affiliative I, II, dependency, restorative, and aggressive-protective subsystems were found. But, ingestive and eliminative subsystems were not correlated with the above seven subsystems significantly, only the positive correlation between the ingestive and eliminative subsystems was found. 3. The explained variance of the 9 subsystems was explained as 56.1% out of a total of one. The sex-related subsystem was the first factor explaining 16.3% of the total variance and then the next 8 factors which resulted in 39.8%. According to the results of this study, the suggestions were as follows: 1. In the nursing practice, nursing assessmentand intervention of the obese should be in cluded not only in ingestive and eliminative subsystems but also in sex-related, attachment-affiliative I, dependency, restorative, aggressive-protective, attachment -affiliative II, and achievement behavioral subsystem. 2. Concerning instruments, some items to measure the eliminative, dependency, and aggressive-protective behavioral subsystems with relatively reliability are needed. 3. Johnson's concept of a dependency subsystem should be clarified. 4. Correlation among the 7 subsystems, and the ingestive and eliminative subsystems should be clarified.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.141-153
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• 1991

The optimal choice of the tax rate and the inflation rate framework is extended to yield relevant interpretations for the optimal fiscal and monetary policy regime in Korea. To study the relationship between the government budget and monetary growth in different environments of policy coordination, two models assuming different degrees of fiscal dominance are developed. By modelling differing institutional arrangements of the fiscal and the monetary authority from an optimal government finance viewpoint, we find the optimal relationship among some important fiscal and monetary variables. By testing the existence of the relationship empirically, we find the characteristics of the optimal policy-mix regime in Korea. The first model-the strong from of fiscal dominance-studies the optimal collection of seigniorage in a period-by-period optimization with standard assumptions on the income velocity of money, deriving a general testable result: the optimal inflation/tax rate ratio co-vary with the marginal revenue ratio. The second model-the weak form of fiscal dominance-studies an implication of the inflationary bias of discretionary monetary policy in the presence of fiscal side distortions. This model shows that the tax rate and the inflation rate can have a positive correlation. Empirical tests of the theoretical results are done for the Korean economy for 1972-1989 period. The test results show that the macroeconomic policy regime in Korea can be characterized by the strong form of fiscal dominance, implying the importance of the government budget in explaining money growth and inflation.