• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.288-293
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• 2016

Purpose: The purpose of this study was to investigate the key factors in designing a three-wheeled two-row soybean reaper (riding type) that is suitable for soybean production, and ensure worker safety by proposing optimal work conditions for the prototype of the designed machine in relation to the slope of the road. Methods: A three-wheeled two-row soybean reaper (riding type) was designed and its prototype was fabricated based on the local soybean-production approach. This approach was considered to be closely related to the prototype-designing of the cutter and the wheel driving system of the reaper. Load distribution on the wheels of the prototype, its minimum turning radius, static lateral overturning angle, tilt angle during driving, and The working and rear overturning (back flip) angle were measured. Based on the gathered information, investigations were conducted regarding optimal work conditions for the prototype. The investigations took into account driving stability and worker safety. Results: The minimum ground clearance of the prototype was 0.5 m. The blade height of the prototype was adjusted such that the cutter was operated in line with the height of the ridges. The load distribution on the prototype's wheels was found to be 1 (front wheel: F): 1.35 (rear-left wheel: RL): 1.43 (rear-right wheel: RR). With the ratio of load distribution between the RL and RR wheels being 1: 1.05, the left-to-right lateral loads were found to be well-balanced. The minimum turning radius of the prototype was 2.0 m. Such a small turning radius was considered to be beneficial for cutting work on small-scale fields. The sliding of the prototype started at $25^{\circ}$, and its lateral overturning started at $39.3^{\circ}$. Further, the critical slope angle for the worker to drive the prototype in the direction of the contour line on an incline was found to be $12.8^{\circ}$, and the safe angle of slope for the cutting was measured to be less than $6^{\circ}$. The critical angle of slope that allowed for work was found to be $10^{\circ}$, at which point the prototype would overturn backward when given impact forces of 1,060 N on its front wheel. Conclusions: It was determined that farmers using the prototype would be able to work safely in most soybean production areas, provided that they complied with safe working conditions during driving and cutting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.33-39
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• 2019

The goal of this study was to investigate how the characteristics of growth and yield are affected by various planting densities in wide-row drill seeding cultivation suitable for mechanized harvesting. Two cultivars ('Hwanggeum' and 'Leebackchal') of proso millet (Panicum miliaceum L.) were planted at varying planting densities [row spacing (20, 30, and 50 cm) and plant spacing (3, 5, 10, and 15 cm)]. The culm length was highest at the planting density of $50{\times}3cm$ and $50{\times}5cm$ for 'Hwanggeum' and $20{\times}3cm$ for 'Leebackchal'. The culm diameter became thinner as the planting density increased. The number of tillering and panicle length showed the same tendency to increase in quantity or length as planting density decreased and was highest at $50{\times}15cm$ when the planting density was lowest. The number of seeds per individual increased as planting density decreased. The thousand grain weight showed no significant differences among treatment plots. The greatest yield of 'Hwanggeum' was obtained at a planting density of $50{\times}3cm$ ($314.9kg{\cdot}10a^{-1}$) and that of 'Leebackchal' was obtained at $50{\times}3cm$ and $50{\times}5cm$ ($358-356kg{\cdot}10a^{-1}$).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.9 s.240
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• pp.1032-1041
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• 2005

This study is performed to investigate the heat transfer characteristics of heat exchanger according to the arrangement of fins as well as fin configuration by using the four times enlarged model. Friction factor, Colburn j factor and goodness factors are compared to each other to estimate performance of each case for 4 different kinds of fins, which are plain, single side slit, double side slit and louver fin. Results show that heat transfer would be altered by fin arrangement and that friction loss is more affected by fin configurations than by the fin arrangements. In particular, heat transfer depends more on the shape of front row than that of rear row. The heat transfer rate of combined fin arrangement increases a lot more under the same pressure drop than that of conventional fin arrangement. This indicates that the heat exchanger of higher efficiency would be designed by the proper combination of fins, of different shapes.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.19-28
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• 2005

In this paper, we proposed a parallel fast 2-D discrete wavelet transform hardware architecture based on lifting scheme. The proposed architecture improved the 2-D processing speed, and reduced internal memory buffer size. The previous lifting scheme based parallel 2-D wavelet transform architectures were consisted with row direction and column direction modules, which were pair of prediction and update filter module. In 2-D wavelet transform, column direction processing used the row direction results, which were not generated in column direction order but in row direction order, so most hardware architecture need internal buffer memory. The proposed architecture focused on the reducing of the internal memory buffer size and the total calculation time. Reducing the total calculation time, we proposed a 4-way data flow scheduling and memory based parallel hardware architecture. The 4-way data flow scheduling can increase the row direction parallel performance, and reduced the initial latency of starting of the row direction calculation. In this hardware architecture, the internal buffer memory didn't used to store the results of the row direction calculation, while it contained intermediate values of column direction calculation. This method is very effective in column direction processing, because the input data of column direction were not generated in column direction order The proposed architecture was implemented with VHDL and Altera Stratix device. The implementation results showed overall calculation time reduced from $N^2/2+\alpha$ to $N^2/4+\beta$, and internal buffer memory size reduced by around $50\%$ of previous works.

• Clinics in Shoulder and Elbow
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• v.13 no.2
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• pp.250-259
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• 2010

Purpose: The purpose of this study was to evaluate the usefulness and clinical results of arthroscopic double row repair with UU stitches for massive, full-thickness, rotator cuff tears. Materials and Methods: Between January 2007 and July 2009, we consulted on 36 massive tears in which it was possible to repair the middle area of the greater tuberosity by arthroscopy. One group consisted of 11 cases that had a double row repair with UU stitches. A second group consisted of 20 cases that had a single row repair with simple stitches. We compared the 2 groups for pain, Activities of Daily Living, UCLA score, and KSS score. We did this pre operatively, and at 6 months, 1 year and final follow-ups. Statistical analysis included Student's t test and a paired t est. Mean age was 59 (48~70); mean follow-up was 28 (12~43) months Results: VAS scores decreased from 7.5 pre operatively to 1.5 post operatively at the last f/u in the $1^{st}$ group (p<0.05). In the $2^{nd}$ group, the score decreased from 7.6 in pre op to 1.8 post operatively at the last f/u (p<0.05). There was no significant difference between the two groups (p>0.05). Mean ADL increased from 11.5 to 25.1 at the last f/u in the $1^{st}$ group (p<0.05); in the $2^{nd}$ group the ADL score increased from 11.3 to 27.5 (p<0.05). There was no significant difference between the two groups (p>0.05). The UCLA score increased from 13.9 to 31.6 in the $1^{st}$ group (p<0.05), while in the $2^{nd}$ group the score increased from 13.8 to 30.1 (p<0.05); there was no significant difference between the two groups (p>0.05). Comparing MRIs at 3 and 6 months post op, there were retears in 3 of 9 cases in the first group, and in 8 of 15 cases in the second group; there was no significant difference between the two groups (p>0.05). Conclusion: Arthroscopic double row repair with UU stitches for massive, full-thickness rotator cuff tears showed no differences in clinical results. However, it was associated with a significant difference in the incidence of retears.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.300-300
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• 2003

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2008.09a
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• pp.240-243
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• 2008

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.307-311
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• 2005

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2008.09b
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• pp.240-243
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• 2008

• Communications of the Korean Mathematical Society
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• v.9 no.4
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• pp.767-772
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• 1994

For an $n \times n$ complex matrix $A = [A_{ij}]$, the permanent of A, per A, is defined by $$ per A = \sub_{\sigma \in S_n}{a_{1 \sigma(1)} a_{2 \sigma(2)} \cdots a_{n \sigma(n)} $$ where $S_n$ stands for the symmetric group on the set {1, 2, ..., n}.