• Spatial Information Research
• /
• v.10 no.4
• /
• pp.551-565
• /
• 2002

To carry out systematic groundwater assessment, exploration and management and to use these for protection of optimal groundwater yield, a data analysis and management system is required. Thus, the object of this research was to develop and apply software that integrates GIS and groundwater modeling: GISGAM (GIS for groundwater analysis and management system). The GIS program ArcView and the groundwater-modeling program MODFLOW were used for the GISGAM. The program components consist of a pre-processor, a processor, and a post-processor for groundwater modeling. In addition, GIS functions such as input, manipulation, analysis and output of data were embedded into the program. In applying the program to pilot area, topography, geology, soil, land use and well databases, and a groundwater flow model were constructed for the study area. This case study revealed the advantage and convenience of groundwater modeling using GIS capabilities. By integrating GIS and the groundwater model, the impact of changing values of hydrogeological constants on model results could be more easily evaluated.

• Korean Journal of Plant Resources
• /
• v.32 no.1
• /
• pp.38-44
• /
• 2019

This study was conducted to establish a domestic cultivation system of a newly introduced yam bean (Pachyrhizus erosus L.). Growth and yield were investigated in response to various cultural practices, such as seedling raising, planting distance, pinching, and flower pruning. Optimum conditions for raising of seedling were an average temperature of $22^{\circ}C$ for 30 days. Considering of the raising efficiency and the convenience of transplanting, 128 cells per tray was a suitable size. When pinching at a height of 120 cm from late July to early August, yield increased by 22% compared to no pinching. Flower pruning between late August and early September increased the number of tubers and tuber yield by 32% in comparison with no flower pruning. Yam bean seedlings planted at $50cm{\times}30cm$ spacing resulted in 30% yield increase as compared to wider spacing of $100cm{\times}30cm$. Our results thus suggested that the optimal combination of cultural practices ($50{\times}30cm$ planting distance, pinching at 120 cm height, and one time of flower pruning) increase profitability by 107%. All these results suggest high possibility of yam bean as a new income crop in Korea.

• Journal of Distribution Science
• /
• v.14 no.11
• /
• pp.83-90
• /
• 2016

Purpose - During the last two years, convenient stores (CS) are emerging as one of the most fast-growing retail trades in Korea. The goal of this work is to forecast and to analyze sales at CS using ARIMA-Intervention model (IM) and exponential smoothing method (ESM), together with sales at supermarkets in South Korea. Considering that two retail trades above are homogeneous and comparable in size and purchasing items on off-line distribution channel, individual behavior and characteristic can be detected and also relative superiority of future growth can be forecasted. In particular, the rapid growth of sales at CS is regarded as an everlasting external event, or step intervention, so that IM with season variation can be examined. At the same time, Winters ESM can be investigated as an alternative to seasonal ARIMA-IM, on the assumption that the underlying series shows exponentially decreasing weights over time. In case of sales at supermarkets, the marked intervention could not be found over the underlying periods, so that only Winters ESM is considered. Research Design, Data, and Methodology - The dataset of this research is obtained from Korean Statistical Information Service (1/2010~7/2016) and Survey of Service Trend of Korea Statistics Administration. This work is exploited time series analyses such as IM, ESM and model-fitting statistics by using TSPLOT, TSMODEL, EXSMOOTH, ARIMA and MODELFIT procedures in SPSS 23.0. Results - By applying seasonal ARIMA-Intervention model to sales at CS, the steep and persisting increase can be expected over the next one year. On the other hand, we expect the rate of sales growth of supermarkets to be lagging and tied up constantly in the next 2016 year. Conclusions - Based on 2017 one-year sales forecasts for CS and supermarkets, we can yield the useful information for the development of CS and also for all retail trades. Future study is needed to analyze sales of popular items individually such as tobacco, banana milk, soju and so on and to get segmented results. Furthermore, we can expand sales forecasts to other retail trades such as department stores, hypermarkets, non-store retailing, so that comprehensive diagnostics can be delivered in the future.

• Steel and Composite Structures
• /
• v.13 no.3
• /
• pp.259-275
• /
• 2012

Concrete filled steel tubular (CFST) member has been widely used in the construction of high-rise buildings for its high axial bearing capacity. It can also be applied on long-span structures such as spatial structures or bridges not only for its high bearing capacity but also for its construction convenience. Concrete casting effect of CFST member is considered in the study of its bearing capacity in this paper. Firstly, in order to authenticate the applicability of constitutive relationship and yield criterion of steel and concrete based on FEM, two ANSYS models are built to simulate and compared with other's test. Secondly, in order to find the huge difference in bearing capacity due to different construction processes, two full-size CFST models are studied when they are horizontally cast and axially compressed. Finally, the effects of slenderness ratio (L/D) and confining parameter (D/t) of CFST members are studied to reveal the intrinsic links between bearing capacity and slenderness ratio or confining parameter.

• Journal of Environmental Policy
• /
• v.14 no.3
• /
• pp.41-73
• /
• 2015

The Korea Emissions Trading System that was launched in Jan. 2015 is expected to be a crucial policy measure to abate domestic $CO_2$ emission. For accomplishing its purpose, prior information on the price discovery process needs to be presented in order to facilitate the trading of spot allowances with different vintages. We develope a customized pricing method for Korean ETS using the concept of term structure and the cost of carry model.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.54 no.3
• /
• pp.19-28
• /
• 2012

Greenhouse cultivation has been increasing for high quality and four season crop production in South Korea. For the cultivation in a greenhouse, maintaining adequate soil moisture at each crop growth stage is quite important for yield stability and quality while the behavior of moisture movement in the soil has complexity and adequate moisture conditions for crops are vary. Drip irrigation systems have been disseminated in the greenhouse cultivation due to advantages including irrigation convenience and efficiency without savvy consideration of the soil moisture redistribution. This study aims to evaluate soil moisture movement of drip irrigation according to the soil moisture uniformity assessment. Richards equation and finite difference scheme were adapted to simulate soil moisture behavior in soil. Soil container experiment was conducted and the model was validated using the data from the experiment. Two discharge rate (1 ${\ell}/hr$ and 2 ${\ell}/hr$) and three spaces between the emitters (10 cm, 20 cm, and 30 cm) were used for irrigation system evaluation. Christiansen uniformity coefficient was also calculated to assess soil moisture redistribution uniformity. The results would propose design guidelines for drip irrigation system installation in the greenhouse cultivation.

• Transactions of Materials Processing
• /
• v.14 no.6 s.78
• /
• pp.496-501
• /
• 2005

Precipitates, present in most commercial alloys, can have a strong influence on strength and hardening behavior of a single crystal. The effect of thin precipitates on the anisotropy of initial slip resistance and hardening behavior of crystals is modeled in this article. For the convenience of the computational derivation and implementation, the material formulation is given in the unrelated intermediate configuration mapped by the plastic part of the deformation gradient. Material descriptions for the considered two phased aggregates consisting in lattice hardening as well as isotropic hardening and kinematic hardening are suggested. Numerical simulations of various loading cases are presented to discuss and assess the performance of the suggested model. From the results of the numerical simulation, it is found that the suggested model represents the initial plastic anisotropy at least qualitatively well and that it has an improved representation of various characteristic hardening behaviors in comparison with conventional hardening descriptions where the precipitate structure is not reflected.

• Korean Journal of Organic Agriculture
• /
• v.22 no.4
• /
• pp.841-854
• /
• 2014

This study aimed to analyze the selection criteria and priority settings for solid culture medium used in hydroponic crop production in farm households. Expert brain storming was carried out to extract solid culture medium selection criteria for hydroponic farming. As a result, 3 criteria of economy (cost), productivity, and environment, and 9 factors were extracted. A questionnaire survey of hydroponic farm households was conducted in Gyeonggi, Gangwon, and Chooncheong provinces. AHP analysis of the hydroponic solid culture medium selection criteria identified productivity as the most important criterion, chosen by 58.7% of the respondents, followed by economy (28.4%) and environment (12.9%). The 9 factors were rated by the respondents in the following decreasing order of importance: 1, crop yield (28.3%); 2, pest occurrence (18.5%); 3, maintenance/management costs (12.0%); 4, convenience of maintenance/management (13.4%); 5, initial investment cost (11.6%); 6, material energy consumption (6.5%); 7, waste recyclability (4.0%); 8, waste disposal costs (3.4%); and 9 environmental emissions (1.81%). These results imply that hydroponic farm households consider cultivation-related quality factors more important than economic factors, such as price of culture medium or installation cost.

• Journal of Distribution Science
• /
• v.21 no.7
• /
• pp.73-82
• /
• 2023

Purpose: Social networking services have been recognized as an attractive distribution channel at a time when efforts to deliver effective messages to consumers are essential amid a flood of advertisements in the multi-media era. In that sense, this study investigated the effect of the scarcity message type (limited-time vs. limited-quantity) and sender type (corporate vs. consumer) on the intention to purchase golf equipment by Instagram distribution channel. Research design, data and methodology: Data from 108 college students in their 20s and 30s with experience using Instagram were collected online through convenience sampling. A frequency analysis, exploratory factor analysis, reliability analysis, independent sample t-test, and two-way analysis of variance were performed using SPSS 23.0. Results: The results showed that limited-quantity messages induce a higher purchase intention than limited-time messages. Similarly, consumer-sent advertisements induce a higher purchase intention than corporate-sent advertisements. Further, there is no statistically significant interaction effect of the scarcity message type and sender type on the intention to purchase golf equipment. Conclusions: This study is meaningful in verifying consumers' purchase intention depending on the type of scarcity message and the type of sender in Instagram advertisements. The results yield significant implications for marketers and several directions for future research.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.5
• /
• pp.825-831
• /
• 2023

The propellers used for big ships have a large diameter and are very heavy. In order to apply a precise and safe work process to them, it is necessary to use an exclusive turning system. For this reason, various techniques are applied to produce them. However, workers' convenience and safety are not taken into consideration enough at production sites. Conventionally, these propellers are designed to be separated as their turning system is loaded and rotated by empty weight. Therefore, it is necessary to replace such a design. This study tries to find the weaknesses of the design and structure of a conventional propeller turning system for large ships, to verify structure integrity of a structure in structural analysis, and to devise a plan for designing a new type of turning system. In the basic concept design and structural analysis for the turning system used in the propeller finishing process for large ships, this study drew the following conclusions. It was possible to develop the work process of the turning system for the propeller finishing process used for large ships, to obtain the dimensions for exterior design through a basic design. Structural analysis was conducted to find the structure integrity of the turning system. As a result, in the rail installed to transfer a gantry, the maximum stress was about 45MPa, about 5.5 times lower than the yield strength 250MPa. Therefore, the turning system was judged to be safe structurally.