• Journal of Distribution Science
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• v.14 no.5
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• pp.97-106
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• 2016

Purpose - Social commerce is a certain way of how people buy some products together with others through the internet sites with mutual interactions among customers with the benefits of SNS when buying some products. At present, China market has some problems due to its rapid growing. However, empirical research or academic approach to social commerce has not been made enough. So, it is important for Chinese social market to develop and enlarge the customers with stability under the reliability and satisfaction. Also it is important for them to have repurchase intention. Nowadays, it is necessary to find the factors on customer satisfaction and trust, whereas consumers' dissatisfaction and unreliability are increasing on social commerce recently. In addition, researches on social commerce have been actively pursued by a variety of domestic and foreign scholars. However, researches on social commerce and Chinese market are short of, and they have some limitations because of the rapid growth of the market even though it is the early stage. The current situation requires researches on consumers' repurchase intention for continuing growth in the future according to the growth of Chinese social commerce. Research design, data, and methodology - The literature and the empirical studies are combined in order to achieve the purpose of the study. Deriving social commerce features and consumer properties as factors affecting the repurchase intention through the literature, and these factors have modeled a series of assumptions about the impact on satisfaction and trust, and have established hypotheses to verify them. The survey which is conducted to test the hypothesis and questionnaires are derived based on the variables discussed in the previous study. Appropriate measures were developed and tested on 227 respondents in China with a cross-sectional questionnaire survey. The path relationships of the research model were analyzed by SPSS 23.0 and Amos 23.0. Results - Research results about social commerce characteristics and factors affecting the repurchase intention are presented to Chinese market companies that adopt business models and consumer characteristics. In addition, this study focuses on the characteristics of social commerce, from two-dimensional characteristics of the consumer satisfaction, trust and the impact on the repurchase. Therefore, social commerce features and consumer properties based on the results of this study may lead the strategic implications that may increase the repurchase intention. Conclusions - The classification reviewing the previous findings related to social commerce and social commerce features affects social commerce repurchase (price discount, interactivity) and consumer characteristics (impulsivity, innovation, collectivism). It affects repurchase on factors and analyzes empirically. The empirical results identify major characteristics (social commerce characteristics, attributes) that affect the repurchase intention, and give the practical implications as well as the business strategies that are able to enhance social commerce repurchase consumers. Social commerce is a certain way of how people buy some products together with others through the internet sites with mutual interactions among customers with the benefits of SNS when buying some products.

• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.139-147
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• 2009

Accurate construction cost estimation in the initial stage of building project plays a key role for project success and for mitigation of disputes. Total construction cost(TCC) estimation of apartment projects in Vietnam has become more important because those projects increasingly rise in quantity with the urbanization and population growth. This paper presents the application of artificial neural networks(ANNs) in estimating TCC of apartment projects. Ninety-one questionnaires were collected to identify input variables. Fourteen data sets of completed apartment projects were obtained and processed for training and generalizing the neural network(NN). MATLAB software was used to train the NN. A program was constructed using Visual C++ in order to apply the neural network to realistic projects. The results suggest that this model is reasonable in predicting TCCs for apartment projects and reinforce the reliability of using neural networks to cost models. Although the proposed model is not validated in a rigorous way, the ANN-based model may be useful for both practitioners and researchers. It facilitates systematic predictions in early phases of construction projects. Practitioners are more proactive in estimating construction costs and making consistent decisions in initial phases of apartment projects. Researchers should benefit from exploring insights into its implementation in the real world. The findings are useful not only to researchers and practitioners in the Vietnam Construction Industry(VCI) but also to participants in other developing countries in South East Asia. Since Korea has emerged as the first largest foreign investor in Vietnam, the results of this study may be also useful to participants in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.887-901
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• 2002

Software management model divided into the software project model and design estimation model, software matrices model, reliability growth model, process improvement model(or process maturity model) etc. Among these software management models, software complexity model make an estimated of the product software. For a practice of software managed, need to guideline of the static analysis of software. Especially, Software complexity model introduced for the estimation of software quantity and program complexity. In case of measurement the software matrices, its need for us to analysis of software quality and products. On the other hand, we known that complexity program include many defects and consuming of source cost. So, we apply to complexity model using of the program complexity, control structure and volume matrices, interface metrics, process complexity metrics method. In this paper, we represent that the analysis of fault data detected during the system test. Also, we analysis of program control structure and interface, volume matrices in various aspect of switching software. Others, their results utilized similar of project and system development.

• Journal of Distribution Science
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• v.13 no.3
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• pp.61-67
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• 2015

Purpose - Exports have long been regarded as significant drivers of sustainable competitive advantage and growth among small and medium enterprises (SMEs). The export activities of SMEs are particularly important in the context of export-oriented economies such as Korea. Although many studies have examined the determinants of exports, it is difficult to find empirical studies about the determinants of the export performance of regional SMEs. This study investigates the determinants of export performance in the regional SME context based on an integrated approach that combines the environment factor of industrial organization theory, competitive strategy theory, and the competences of the resource-based view. Research design, data, and methodology - To empirically analyze the determinants of export performance in the regional SMEs, data were collected from firms in the Daegu metropolitan area. Data were collected directly through questionnaire surveys; in addition, secondary financial data were also taken from the KIS-VALUE database. Out of the 175 responses that were received, 143 were considered to be worth examining. After testing the reliability and validity of the variables through multiple items such as environmental turbulence and competitive strategy, hypotheses were verified by using five multi-regression models. These models were: a control model with organizational size and age, an environmental model with technology and market turbulence, a competency model with R&D and foreign distribution channels, a strategy model with product and market differentiation, and an integrated model including all of these variables. Results - First, as a control variable, the organization size has significant positive effects on export performance. Second, technology turbulence based on industrial organization theory has significant positive effects on export performance, but market turbulence does not affect export performance. Third, the foreign market distribution competency of the resource-based view has strong positive effects on export performance, but the R&D competency does not affect export performance. Fourth, the product differentiation strategy from competitive strategy theory positively impacts export performance, but market differentiation does not affect export performance. Finally, in the integrated model, only the foreign distribution competency of the resource-based view has a significant effect on export performance. Conclusions - The empirical results of this study verified the usefulness of the rationales behind the three theories to explain the export performance of the regional SMEs, especially the importance of the foreign market distribution competency from the resource-based view. With regard to practical considerations, this study's implications suggest that the use of technological environmental changes by industries is better than the use of market changes. Further, the use of the product differentiation strategy is more effective than the use of the market-driving strategy, and the distribution channel competency plays a stronger role than the technology-oriented competency with regard to the export performance position of regional SMEs. Future studies should examine relational perspectives, such as trust among channel partners. Therefore, the configuration approach is more useful in enhancing pragmatism by comparing high- and low-export companies.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.878-885
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• 2017

Objective: Glucose is an essential fuel in the energy metabolism and synthesis pathways of all mammalian cells. In lactating animals, glucose is the major precursor for lactose and is a substrate for the synthesis of milk proteins and fat in mammary secretory (alveolar) epithelial cells. However, clear utilization of glucose in mammary cells during lactogenesis is still unknown, due to the lack of in vitro analyzing models. Therefore, the objective of this study was to test the reliability of the mammary alveolar (MAC-T) cell as an in vitro study model for glucose metabolism and lactating system. Methods: Undifferentiated MAC-T cells were cultured in three types of Dulbecco's modified Eagle's medium with varying levels of glucose (no-glucose: 0 g/L, low-glucose: 1 g/L, and high-glucose: 4.5 g/L) for 8 d, after which differentiation to casein secretion was induced. Cell proliferation and expression levels of apoptotic genes, Insulin like growth factor-1 (IGF1) receptor, oxytocin receptor, ${\alpha}S1$, ${\alpha}S2$, and ${\beta}$ casein genes were analyzed at 1, 2, 4, and 8 d after differentiation. Results: The proliferation of MAC-T cells with high-glucose treatment was seen to be significantly higher. Expression of apoptotic genes was not affected in any group. However, expression levels of the mammary development related gene (IGF1 receptor) and lactation related gene (oxytocin receptor) were significantly higher in the low-glucose group. Expressions of ${\alpha}S1-casein$, ${\alpha}S2-casein$, and ${\beta}-casein$ were also higher in the low-glucose treated group as compared to that in the no-glucose and high-glucose groups. Conclusion: The results demonstrated that although a high-glucose environment increases cell proliferation in MAC-T cells, a low-glucose treatment to MAC-T cells induces higher expression of casein genes. Our results suggest that the MAC-T cells may be used as an in vitro model to analyze mammary cell development and lactation connected with precise biological effects.

• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.1
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• pp.4279-4295
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• 1977

Two types of model were established in order to product the soil moisture content by which information on irrigation could be obtained. Model-I was to represent the soil moisture depletion and was established based on the concept of water balance in a given soil profile. Model-II was a mathematical model derived from the analysis of soil moisture variation curves which were drawn from the observed data. In establishing the Model-I, the method and procedure to estimate parameters for the determination of the variables such as evapotranspirations, effective rainfalls, and drainage amounts were discussed. Empirical equations representing soil moisture variation curves were derived from the observed data as the Model-II. The procedure for forecasting timing and amounts of irrigation under the given soil moisture content was discussed. The established models were checked by comparing the observed data with those predicted by the model. Obtained results are summarized as follows: 1. As a water balance model of a given soil profile, the soil moisture depletion D, could be represented as the equation(2). 2. Among the various empirical formulae for potential evapotranspiration (Etp), Penman's formula was best fit to the data observed with the evaporation pans and tanks in Suweon area. High degree of positive correlation between Penman's predicted data and observed data with a large evaporation pan was confirmed. and the regression enquation was Y=0.7436X+17.2918, where Y represents evaporation rate from large evaporation pan, in mm/10days, and X represents potential evapotranspiration rate estimated by use of Penman's formula. 3. Evapotranspiration, Et, could be estimated from the potential evapotranspiration, Etp, by introducing the consumptive use coefficient, Kc, which was repre sensed by the following relationship: Kc=Kco$.$Ka＋Ks‥‥‥(Eq. 6) where Kco : crop coefficient Ka : coefficient depending on the soil moisture content Ks : correction coefficient a. Crop coefficient. Kco. Crop coefficients of barley, bean, and wheat for each growth stage were found to be dependent on the crop. b. Coefficient depending on the soil moisture content, Ka. The values of Ka for clay loam, sandy loam, and loamy sand revealed a similar tendency to those of Pierce type. c. Correction coefficent, Ks. Following relationships were established to estimate Ks values: Ks=Kc-Kco$.$Ka, where Ks=0 if Kc,=Kco$.$K0$\geq$1.0, otherwise Ks=1-Kco$.$Ka 4. Effective rainfall, Re, was estimated by using following relationships : Re=D, if R-D$\geq$0, otherwise, Re=R 5. The difference between rainfall, R, and the soil moisture depletion D, was taken as drainage amount, Wd. {{{{D= SUM from { {i }=1} to n (Et-Re-I+Wd)}}}} if Wd=0, otherwise, {{{{D= SUM from { {i }=tf} to n (Et-Re-I+Wd)}}}} where tf=2∼3 days. 6. The curves and their corresponding empirical equations for the variation of soil moisture depending on the soil types, soil depths are shown on Fig. 8 (a,b.c,d). The general mathematical model on soil moisture variation depending on seasons, weather, and soil types were as follow: {{{{SMC= SUM ( { C}_{i }Exp( { - lambda }_{i } { t}_{i } )+ { Re}_{i } - { Excess}_{i } )}}}} where SMC : soil moisture content C : constant depending on an initial soil moisture content $\lambda$ : constant depending on season t : time Re : effective rainfall Excess : drainage and excess soil moisture other than drainage. The values of $\lambda$ are shown on Table 1. 7. The timing and amount of irrigation could be predicted by the equation (9-a) and (9-b,c), respectively. 8. Under the given conditions, the model for scheduling irrigation was completed. Fig. 9 show computer flow charts of the model. a. To estimate a potential evapotranspiration, Penman's equation was used if a complete observed meteorological data were available, and Jensen-Haise's equation was used if a forecasted meteorological data were available, However none of the observed or forecasted data were available, the equation (15) was used. b. As an input time data, a crop carlender was used, which was made based on the time when the growth stage of the crop shows it's maximum effective leaf coverage. 9. For the purpose of validation of the models, observed data of soil moiture content under various conditions from May, 1975 to July, 1975 were compared to the data predicted by Model-I and Model-II. Model-I shows the relative error of 4.6 to 14.3 percent which is an acceptable range of error in view of engineering purpose. Model-II shows 3 to 16.7 percent of relative error which is a little larger than the one from the Model-I. 10. Comparing two models, the followings are concluded: Model-I established on the theoretical background can predict with a satisfiable reliability far practical use provided that forecasted meteorological data are available. On the other hand, Model-II was superior to Model-I in it's simplicity, but it needs long period and wide scope of observed data to predict acceptable soil moisture content. Further studies are needed on the Model-II to make it acceptable in practical use.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.669-681
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• 2023

Studies have tried to apply remote sensing technology, a non-destructive survey method, instead of the existing destructive survey, which requires relatively large labor input and a long time to estimate chlorophyll content, which is an important indicator for evaluating the growth of fruit trees. This study was conducted to non-destructively evaluate the chlorophyll content of pear tree leaves using unmanned aerial vehicle-based hyperspectral imagery for two years(2021, 2022). The reflectance of the single bands of the pear tree canopy extracted through image processing was band rationed to minimize unstable radiation effects depending on time changes. The estimation (calibration and validation) models were developed using machine learning algorithms of elastic-net, k-nearest neighbors(KNN), and support vector machine with band ratios as input variables. By comparing the performance of estimation models based on full band ratios, key band ratios that are advantageous for reducing computational costs and improving reproducibility were selected. As a result, for all machine learning models, when calibration of coefficient of determination (R²)≥0.67, root mean squared error (RMSE)≤1.22 ㎍/cm², relative error (RE)≤17.9% and validation of R²≥0.56, RMSE≤1.41 ㎍/cm², RE≤20.7% using full band ratios were compared, four key band ratios were selected. There was relatively no significant difference in validation performance between machine learning models. Therefore, the KNN model with the highest calibration performance was used as the standard, and its key band ratios were 710/714, 718/722, 754/758, and 758/762 nm. The performance of calibration showed R²=0.80, RMSE=0.94 ㎍/cm², RE=13.9%, and validation showed R²=0.57, RMSE=1.40 ㎍/cm², RE=20.5%. Although the performance results based on validation were not sufficient to estimate the chlorophyll content of pear tree leaves, it is meaningful that key band ratios were selected as a standard for future research. To improve estimation performance, it is necessary to continuously secure additional datasets and improve the estimation model by reproducing it in actual orchards. In future research, it is necessary to continuously secure additional datasets to improve estimation performance, verify the reliability of the selected key band ratios, and upgrade the estimation model to be reproducible in actual orchards.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.126-135
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• 2015

This study was conducted to develop a large scale map of species-specific plantation sites based on selected environmental variables such as topography, soil, and climatic factors in Namwon city. Site index equations by tree species were first regressed to 27 environmental variables that could influence the productivity of forest sites using digital forest site maps, digital climate maps, and the 5th National Forest Inventory data. Site index equations by tree species were all evaluated to estimate site productivity using 4-5 environmental variables, and the models' reliability was confirmed based on evaluation statistics. The determination coefficients of site index equations by species ranged from 0.42 to 0.76. With the site index equations, the site conditions appropriate for productive sites by species were considered to assess spatial distribution of productive areas for each species. The final map for optimal plantation in Namwon city was produced based on both site index equations and site conditions appropriate for productive sites by each species using GIS technique. Field survey was conducted to evaluate the suitability of selected species on the map of species-specific plantation sites. Results showed that the plantation map provides relatively reasonable spatial distribution of productive areas for selected species. It was revealed, however, that the sites evaluated as 'not suitable' for any tree species should be revised and complemented with additional information, especially with the site conditions appropriate for productive sites by species of interest. The outcomes of this study are expected to provide information for making customized species-specific plantation maps.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.429-438
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• 1997

Mechanical valve is one of the most widely used implantable artificial organs of which the reliability is so important that its failure means the death of patient. Therefore early noninvasive detection is essentially required, though mechanical valve failure with thrombosis is the most common. The objective of this paper is to detect the thrombosis formation by spectral analysis and neural network. Using microphone and amplifier, we measured the sound from the mechanical valve which is attached to the pneumatic ventricular assist device. The sound was sampled by A/D converter(DaqBook 100) and the periodogram is the main algorithm for obtaining spectrum. We made the thrombosis models using pellethane and silicon and they are thrombosis model on the valvular disk, around the sewing ring and fibrous tissue growth across the orifice of valve. The performance of the measurment system was tested firstly using 1 KHz sinusoidal wave. The measurement system detected well 1KHz spectrum as expected. The spectrum of normal and 5 kinds of thrombotic valve were obtained and primary and secondary peak appeared in each spectrum waveform. We find that the secondary peak changes according to the thrombosis model. So to distinguish the secondary peak of normal and thrombotic valve quantatively, 3 layer back propagation neural network, which contains 7, 000 input node, 20 hidden layer and 1 output was employed The trained neural network can distinguish normal and valve with more than 90% probability. As a conclusion, the noninvasive monitoring of implanted mechanical valve is possible by analysing the acoustical spectrum using neural network algorithm and this method will be applied to the performance evaluation of other implantable artificial organs.

• Journal of Distribution Science
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• v.12 no.6
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• pp.31-39
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• 2014

Purpose - Environmental issues, climatic changes, and greenhouse gases are problems to be solved at a global level. With an increased emphasis on the environmental and social responsibility of the management of companies, the manner in which companies approach quality-oriented culture and their individual sustainability management are being discussed as truly important issues to help them secure their competitiveness and growth strategies. This study proposes strategic directions to help manufacturers not only in expanding their competitive quality-oriented company culture but also in strengthening their sustainability management abilities. This study conducts a literature review and empirical research to examine how significantly the variables of a quality-oriented company culture, customer-centered management, and process-centered and supply chain management-centered cooperation affect sustainability management performance in relation to economic profitability, environmental integrity, and social responsibility. Research design, data, and methodology - To verify research models and hypotheses, the study examined 170 companies using a questionnaire survey conducted over six weeks, and involved the performance of data analysis on 146 samples. Questionnaire responses were calibrated based on a Likert scale. The study used the Smart PLS 2.0 program designed for PLS (partial least squares), an analysis instrument of SEM (structural equation modeling). The study then verified empirical research hypotheses working on reliability analysis, validity analysis, factorial analysis, and path analysis. Results - Among the nine hypotheses, four are accepted and the rest are rejected. A quality-oriented company culture focusing on customer-centered management significantly influenced the maintainability management performance of environmental integrity and social responsibility, while economic profitability was dismissed. A process-focused quality-oriented company culture was significantly concerned with economic profitability but not with environmental integrity or social responsibility. A supply-chain cooperative company culture had a significant effect on economic profitability but not on environmental integrity or social responsibility. Conclusion - This study proposes strategic directions to help manufacturers expand their competitive quality-oriented company culture as well as strengthen abilities with sustainability management. It conducts a literature review and empirical research to examine how significantly the variables of quality-oriented company culture, customer-centered management, and process-centered and supply chain management-centered cooperation affect sustainability management performance in relation to economic profitability, environmental integrity, and social responsibility. There are two main conclusions. First, companies should consider the need for social responsibility management and environmental transparent management-focused maintainability management as avenues to create new markets and business, thereby helping the companies secure a reputation for having a customer and process-centered quality-oriented company culture by creating shared values between supply chains and enabling win-win situations through cooperation. Second, we are marching towards a creative win-win era from a society of conflicts and ruptures. Companies should understand that social responsibility management and supply chain management (SCM)-focused cooperation are the foundations of sustainable development, as they try to improve their culture while pursuing both win-win relationships with interested parties and equity in various conflictive relations.