• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.6
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• pp.419-423
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• 2015

The flowing caused by artificial upwelling structure occurs ascending water flowing and vortex of rear side. In this moment, plentiful nutrient in the bottom water moves to the surface of the water and makes those plankton and fishing ecology promoted so that the fishing productivity can be enhanced. In this study, the changes of the upwelling flowing is included in consideration of the conditions of stratification by using CFD. In the conclusion, the closer upwelling effect is from the artificial upwelling structure, the better effectiveness comes out. Regardless of the conditions of stratification, only the upwelling feature from the bottom to the surface was shown up. But considering the conditions of stratification, the repeated flowing feature between upwelling and downwelling was verified.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.665-671
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• 2012

A remarshalling is studied as an important operational strategy in an automated container terminal to enhance the productivity of container handling. This means the rearrangements of the containers scattered at a vertical yard block. The dispatching problem for remarshalling is selecting the remarshalling operation considering the available operation time and deciding the operation sequencing to maximize the effectiveness of remarshalling. This study develops the optimal mathematical model for yard crane dispatching problem with mixed integer program and explains dispatching problem using an example. However it is difficult to apply this model to a field problem because of its computational time. Therefore, we compare the representative 5 dispatching rules for real world adaption. In a numerical experiment, maximum weight ratio(MR) rule shows an overall outstanding performance.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.92-97
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• 2001

Soil characteristics and crop productivity was compared between 5 soil physical treatment plots: check, reversion, subsoiling, explosive subsoiling and drainage in salt accumulated Gangseo Fine sandy loam soil from 1999 to 2000. Physical treatments of subsoil improved soil physical properties in the following order, reversion > drainage > explosive subsoiling > subsoiling > check. The effectiveness of physical treatment was sustained to the 2nd year after treatment. Soil moisture content of subsoil was highest in the reversion treatments and decreased in the order of drainage, subsoiling, and check. However there was little difference between treatments. The physical treatments increased fluctuation of soil moisture content. However the crop yield in the physical treatment plots were increased. It was considered that the increase of crop yield was caused by improvement of soil physical properties rather than soil water holding in the soil. An average increase rate of crop yield by physical treatments was 10 to 20 percent.

• International Area Studies Review
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• v.15 no.2
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• pp.51-76
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• 2011

Since Japanese government took reformative measures of public investment in the period of 2000s, this paper investigates how the economic effects of public investments has improved in the period of 2000s. The empirical findings do not show that the output elasticity with respect to public capital has been higher in the 2000s than that of 1990s. Rather, some output elasticity estimates for 2000s has lowered after the advent of year 2000. In addition, the impact of public capital on the productivity of private capital has not improved in the 2000s compared with that of 1990s in Japan. Another major finding shows that the crowding-out effect of public investment has been stronger in the 2000s than before. Those findings imply that the reforms done by Japanese government in the 2000s regarding public investment do not spread out into the private aggregate production and investment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.657-661
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• 2019

The automobile industry is representative industry of complex characteristics, which employing 10 million people, the largest manufacturing industry over $1 trillion in sales and assembling with 20,000 parts to make complete automobile and automobile assembly processes have a lower automation rate than other processes, which is labor intensive processes of assembling to painted body with 3,000 components such as seats, built-in, instrument panel, glass, engine, transmission units. However, the current assembly process does not have real-time monitoring. If a tool position tracking system is adapted to assembly process for directing consistent work order and checking for missing work, the productivity and quality improvement of the assembly process can be achieved by preemptively preventing possible defects in the assembly process. So, this paper aims to develop a Tool Position tracking system using UWB(Ultra Wide Band) with trilateration and proves their effectiveness for real-time monitoring of automotive assembly process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.127-132
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• 2019

In this paper, we propose a visual inspection method of automotive parts for injection molding to improve the appearance quality and productivity of automotive parts. Exterior inspection of existing injection molding automobile parts was generally done by manual sampling inspection by human. First, we applied the edge-tolerance vision inspection algorithm ([1] - [4]) for vision inspection of electronic components (TFT-LCD and PCB) And we propose a new visual inspection method to overcome the problem. In the proposed visual inspection, the inspection images of the parts to be inspected are aligned on the basis of the reference image of good quality. Then, after partial adaptive binarization, the binary block matching algorithm is used to compare the good binary image and the test binary image. We verified the effectiveness of the edge-tolerance vision check algorithm and the proposed appearance vision test method through various comparative experiments using actual developed equipment.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.1
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• pp.21-29
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• 2021

The emerging smart world based on IoT requires deployment of a large number of diverse sensors to generate data pertaining to different applications. Recent years have witnessed a plethora of IoT solutions beneficial to various application domains, IoT techniques also help boost agricultural productivity by increasing crop yields and reducing losses. This paper presents a predictive IoT smart farm platform for forcast services. We built an online agricultural forecasting service that collects microclimate data from weather stations in real-time. To demonstrate effectiveness of our proposed system, we designed a frost and pest forecasting modes on the microclimate data collected from weather stations, notifies the possibilities of frost, and sends pest forecast messages to farmers using push services so that they can protect crops against damages. It is expected to provide effectively that more precise climate forecasts thus could potentially precision agricultural services to reduce crop damages and unnecessary costs, such as the use of non-essential pesticides.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.83-92
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• 2021

Recently many organizations have adopted 'untact' work due to social distancing caused by Coronavirus-19. To clarify some controversy about the effectiveness from 'untact' work, it is necessary to examine the cognition of organizational members. This study identified issues in 'untact' work from the literature review, analyzed the content of in-depth interviews with workers and managers experiencing 'untact' work, and compared both groups' cognition by applying the co-orientation model. Both groups pointed out the communication difficulty as the top disadvantage and showed no significant differences in job satisfaction, organizational commitment, and work-life balance. However, the two groups showed significant differences in their cognition about performance evaluation (agreement and workers' congruence) and productivity enhancement (workers' accuracy). This paper has an academic contribution in that it has focused on cognitive gaps between workers and managers, urges organizations to devise ways to reduce the gaps, and suggests future studies with quantitative approaches.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.4
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• pp.32-42
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• 2021

The printing process can have to print various colors with a limited capacity of printing facility such as ink containers that are needed cleaning to change color. In each container, cleaning time exists to assign corresponding inks, and it is considered as the setup cost required to reduce the increasing productivity. The existing manual method, which is based on the worker's experience or intuition, is difficult to respond to the diversification of color requirements, mathematical modeling and algorithms are suggested for efficient scheduling. In this study, we propose a new type of scheduling problem for the printing process. First, we suggest a mathematical model that optimizes the color assignment and scheduling. Although the suggested model guarantees global optimality, it needs a lot of computational time to solve. Thus, we decompose the original problem into sequencing orders and allocating ink problems. An approximate function is used to compute the job scheduling, and local search heuristic based on 2-opt algorithm is suggested for reducing computational time. In order to verify the effectiveness of our method, we compared the algorithms' performance. The results show that the suggested decomposition structure can find acceptable solutions within a reasonable time. Also, we present schematized results for field application.

• Journal of Industrial Convergence
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• v.20 no.7
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• pp.31-36
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• 2022

There is a growing perception that HR management that streamlines corporate resources is necessary to retain competitive advantage. In this study, data-based HR management is focused on the perception of HR job experts and data-based HR management execution and utilization prospects at corporate sites. The subjects of the study were three HR planning/management job experts of three firms specializing in IT services in Pangyo, and focused on identifying data-based HR management execution, measurement, analysis tools, and utilization level. As a research method, open coding, axis coding, selective coding procedure based on evidence theory was presented. As a result of in-depth interviews, corporate HR management measurement indicators were divided into three areas: employee, productivity, and culture. Through this study, it was possible to find the significance of perception of the company site as to what measurement tools and mechanisms the company implemented and measured the effectiveness and efficiency of HR management.