• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.334-340
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• 2003

풋고추의 재배면적은 시설채소 면적이 증가하면서 연중 생산이 가능하게 되어 급속히 증가하고 있으며 신선 채소류에 대한 선호도가 늘어나면서 풋고추의 소비량이 늘어나고 있다. 2001년 현재 고추의 시설재배 면적은 5,517㏊로써 과채류 시설재배면적의 10%를 차지하고 있다. 재배지역별로는 경남, 전남, 광주, 충남지역이 전체 재배면적의 73%를 차지하고 있으며 풋고추는 시설재배로 대부분이 주산단지로 이루어져 있어 선별작업기계화가 요망되고 있다. 이와 같이 풋고추선별에 대한 기계화 요구도가 높은 반면 아직까지 풋고추의 선별작업은 전적으로 인력에 의존하므로 많은 노동력이 소요되며 작업능률이 낮고 육안에 의존하기 때문에 정확한 크기선별이 곤란한 실정이다. 또한 고추의 선별ㆍ포장에 소요되는 작업노력으로 인하여 주산지별로 선택ㆍ포장 작업의 기계화 요구도가 높다. (중략)

• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.348-354
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• 2011

Various crop spacing methods have been implemented so far for the greenhouse and plant factory applications. However, there is no generally accepted parameter for evaluation of plant spacing efficiency in plant production system. In this study, 'Planted Area Index' (PAI) of a spacing method is defined as the ratio of the planted area in the field to required planted area using the spacing method when no transplanting operation is assumed. Three common types of spacing methods for plane placement of the plants were modeled mathematically. For calculating the planted area, an optimal growth radius function (R(t)) is needed. Function of the days after transplanting stage gives a radius of an optimal circle area for the living plants. A computer simulation was developed to calculate the PAI, based on three crop spacing methods and four optimal growth radius functions. In general, the 1-D zigzag spacing showed the best PAI. Moreover, it gives an example on how to apply the PAI for the design.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.3
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• pp.122-128
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• 2014

When evaluating effectiveness of a program, there is a tendency to simply compare the performances of the treated before and after the program or to compare the differences in the performances of the treated and the untreated before-after the program. However, these ways of evaluating effectiveness have problems because they can't account for environmental changes affecting the treated and/or effects coming from the differences between the treated and the untreated. Therefore, in this paper, panel data analysis (fixed effects model) is suggested as a means to overcome these problems and is utilized to evaluate the effectiveness of fusion technology program conducted by Ministry of Trade, Industry and Energy, Korea. As a result, it turns out that the program has definitely positive impacts on the beneficiary in terms of sales, R&D expenditure, and employment.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.165-173
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• 2019

In this paper, we apply a discrete wavelet packet transform (DWPT) to reduce the influence of interference in global positioning system (GPS) signals and compare the interference mitigation performance of various wavelets. By applying DWPT to the received signal, we can gradually divide the received signal band into low-pass and high-pass bands. After calculating the average power for the separate bands, we can determine whether there is interference by comparing the value with the given threshold. For a band that includes interference, we can reconstruct the whole band signal using inverse DWPT (IDWPT) after applying a nulling method that sets all of the wavelet coefficients to 0. The reconstructed signals are correlated with the pseudorandom noise (PRN) codes to acquire GPS signals. The performance evaluation is based on the number of satellite signals whose peak ratio (defined as the ratio of the first and second correlation peak values in the acquisition stage) exceeds the threshold. In this paper, we compare and evaluate the performance of 6 wavelets including Haar, Daubechies, Symlets, Coiflets, Biorthogonal Splines, and Discrete Meyer.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.461-467
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• 2015

The 6th industrialization is one of the most important policies for Korean agricultural sector, and Korean government allocates the large portion of policy budget to promote the 6th industrialization. However, recently, Korean government has experienced the confusion and inefficiency due to too many policy programs for the 6th industrialization. The purpose of this paper is to analyze the current policy programs for the 6th industrialization and to suggest the several guidelines for the more efficient policy system, including the priority of policy programs for the 6th industrialization. The results of studies present a few findings as follows: First, Korean government should evenly promote the 1st, 2nd, and 3rd industry in agricultural sector. Second, the main agent of the 6th industrialization needs to be the ministry of agriculture, food and rural affairs. Third, the policy resource for the 6th industrialization should be focused on the prominent farmers or enterprises. Forth, the policy programs for the 6th industrialization need to be grouped.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.195-198
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• 2006

Zinc phosphate coating is required in nearly all steel cold forging operations. However, the chemical byproducts of this lubricant system are difficult to dispose of and have a negative environmental impact. In order to replace zinc phosphate based lubricants partially or completely, candidate lubricant has been developed in this study. The performance evaluation of these lubricants was conducted using the double cup extrusion test and spike forging test. With the use of the commercial FEM code DEFORM, friction factor calibration curves, i.e. cup height ratio vs. punch stroke and spike height vs. punch stroke, were established for different friction factor values. By matching the cup height ratio and the punch stroke and spike height vs. punch stroke from experiment to that obtained from FE simulations, the friction factor of the lubricants was determined. Three water-soluble lubricants; namely, Mec Homat, Royalcoat, and the developed lubricant were found to perform comparable to or better than zinc phosphate.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.99-105
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• 2018

PURPOSE: The aim of this study was to evaluate the concurrent validity and clinical usefulness of the universal plastic goniometer to measure the range of motion of the internal and external rotation of the hip joint using the three dimensional motion analysis which can analyze the joints and segment movements in the most objective and quantitative method. METHODS: Clinical and kinematic data were collected from thirty individuals using a universal plastic goniometer and a ten camera motion analysis system. Passive hip rotation range was obtained three trials for left and right hip joints using two measure methods simultaneously. RESULTS: There were significant differences between all matching measures of the two measures of internal and external rotation of the hip joint (p<.05). The relationship between the two tests for all measurements of the internal and external rotation of the hip was statistically significant with correlation coefficient form r=.87 to .96. (p<.01). CONCLUSION: Clinical measurement of the internal and external rotation of the hip using a universal plastic goniometer is effective to assess the hip condition. However, application of universal plastic goniometer requires careful attention in more accurate evaluation and research verification of the internal and external rotation of hip joint.

• Journal of Welding and Joining
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• v.22 no.2
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• pp.38-45
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• 2004

Ultrasonic signals transmitted through adhesively bonded plates were used to evaluate parameters related to attenuation and frequency in the adhesively bonded joint. The kinds of bonding materials with a different bonding thickness of constant pressure were used. And ultrasonic diagnosis was evaluated by p-wave sensor of 10MHz. FFT has been performed to determine bond-layer parameters such as effective thickness and frequency for adhesively bonded joint of A16061 plates in comparison with measured to theoretical ratios. When variable thickness exists, the ultrasonic spectrum was changed the frequency wave. The more materials thickness and the higher the frequency, the larger shift was observed. Measured ratios for cases of bond thickness and variety bonding materials are then used to determine bond parameters. The results show that the technique can be applied to the characterization of adhesively bonded joint.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.120-129
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• 2012

As the recent advancement of automobile industry, there has been a great interest in the thermal comfort of the passengers inside the cabin of an automobile. Thermal comfort is affected by temperature, velocities, and mean radiation temperature of air, thermal resistance of clothes and physical active level of human. The present study performed computational analysis to select the location of air-conditioning vent that improves thermal comfort inside the cabin. In order to do this, we considered various air vent positions, and thermal flow analysis of each case is performed using CFD for the cabin with four passengers. The thermal comfort is evaluated using the computational results and the optimum location of air vent is suggested.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.133-138
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• 2017

Inverter-Type refrigerators are known to consume less energy by varying the inverter frequency according to indoor temperatures and refrigerant pressure through indoor-outdoor communication. However, many commercial operators cannot afford to replace indoor units with ones capable of communication. In a non-communication configuration, indoor units are connected with an inverter-type outdoor unit without intercommunication abilities. The research goal is finding appropriate operating parameters to achieve energy efficiency. Thus, an operation algorithm with two modes is proposed, i.e., one to search the best operating parameters and one for normal operation with the best parameters. The experimental evaluation showed 11.27% reduction in energy consumption, indicating a good applicability of the algorithm.