• Journal of Korea Society of Industrial Information Systems
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• v.11 no.4
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• pp.82-92
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• 2006

In the field of image recognition, research on face recognition has recently attracted a lot of attention. The most important step in face recognition is automatic eye detection researched as a prerequisite stage. Existing eye detection methods for focusing on the frontal face can be mainly classified into two categories: active infrared(IR)-based approaches and image-based approaches. This paper proposes an eye region detection method in non-frontal faces. The proposed method is based on the edge--based method that shows the fastest computation time. To extract eye region in non-frontal faces, the method uses edge orientationhistogram of the global region of faces. The problem caused by some noise and unfavorable ambient light is solved by using proportion of width and height for local information and relationship between components for global information in approximately extracted region. In experimental results, the proposed method improved precision rates, as solving 3 problems caused by edge information and achieves a detection accuracy of 83.5% and a computational time of 0.5sec per face image using 300 face images provided by The Weizmann Institute of Science.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.409-420
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• 2016

Korea is expected to enter 'Super Aged Society' in 2026. However, as walking is the very basic human right of mobility, securing safe and convenient moving of elderly people comprising the majority of transportation vulnerable is thought to be the most basic welfare, which can be easily neglected. From this perspectives, this study provides the walking characteristics of elderly people to be used in design of pedestrian facilities. The analysis of the measurements using Motion Analysis Systems shows that all walking factors of elderly people is 75% level of the younger group. Elderly group shows slower movement, reduced shoulder movement and increased ankle movement compared to the others. Also, foots are risen less and ground repulsive force is increased. Cluster analysis shows that the group of the elderly shows high variability inside the group, and 2 or 3 clusters can be formed with factors of Walking, Balance and Muscles. These walking characteristics can be used in designing pedestrian road, slope and step height of roadway facilities.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.3
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• pp.264-274
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• 2013

This study investigates long-term trends and characteristics of aerosol light scattering coefficient at Seoul and Baengnyeongdo in order to understand aerosol optical and radiative properties around Korea. The analysis period is limited to one year of 2011. First, the aerosol scattering coefficients (${\sigma}_{sp}$) of both sites show strong linear dependence on the $PM_{2.5}$ mass concentrations with significant correlations between both. Further, correlations and sensitivity between ${\sigma}_{sp}$ and $PM_{2.5}$ increase with relative humidity, implying both relationships are strongly dependent upon moisture amounts in the atmosphere. This study applied 3-step careful quality control procedures to the analysis of ${\sigma}_{sp}$ for the insurance of data confidence. For the relationship analysis of extinction coefficients (${\sigma}_{ext}$) to visibility and aerosol optical depth, ${\sigma}_{sp}$ observed at 3 p.m. have been used with help of aerosol absorption coefficients (${\sigma}_{ap}$) in order to remove its dependence upon relative humidity, and also those of rainy period have been excluded. As expected, ${\sigma}_{ext}$ estimated are inversely proportional to visibility observation by eye. Finally, aerosol extinction coefficients have been vertically integrated with an assumption of nearly well-mixed within an e-folding height to determine aerosol optical depth, and compared with those retrieved from sunphotometer. The results show a reasonable agreement in spite of an inherent difference of each definition. We expect these findings would help to eventually understand aerosol radiative forcing and its effect on the regional climate change around Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.4
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• pp.213-218
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• 2009

Electrowinning process recovers uranium with actinide elements from spent fuels and is a key step in the Pyroprocessing because of proliferation resistance. An analysis of heat transfer of the Electrowinning cell was conducted to develop basic tool for designing engineering-scale Electrowinner. For the calculation of the heat transfer, ANSYS CFX commercial code was adapted. As a result of the calculation, the vertical Heating Zone length had great effect upon temperature of LiCl-KCl eutectic salt. To maintain constant temperature in the salt, the Heating Zone length should be three times longer than the height of the salt. However, the argon and salt temperatures were barely affected by the Cooling Zone length. The temperature under the Cell cover was mainly influenced by the number of the cooling plates. When the cooling plates were installed more than the number of 5, temperature under the cover was maintained below $250^{\circ}C$. These temperature properties had similar tendency toward the temperature of the Cell which was measured from experiments, Simulated heat transfer information from this study could be used to design engineering-scale Electrowinner.

• Journal of Forest and Environmental Science
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• v.23 no.1
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• pp.11-19
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• 2007

This study was designed to analyze the economic efficiency that is needed to develop and make practical application of a mobile carbonization apparatus, which are able to make wood charcoals and pyroligneous liquid at the logging field with debris. B/C ratio was employed to make an economic analysis, and sensitivity analysis with respect to change in price and interest rates also was made. Cylindrical type is the proper type for the mobile carbonization apparatus, when important factors such as handling capacity, a carbonization time, quality of products and assembling ability were considered. It weighs 400 kg, and a three-step fold-up equipment. The size of 2 (diameter) by 2.4 m (height) carbonization equipment required 1,500 kg wood debris per batch. A forty-eight to fifty-two carbonization time produced 300 kg of wood charcoal and $45{\ell}$ of pyroligneous liquid. The average life span of the apparatus was 5 years. If the private enterprise operated 100 batch, 80 batch, and 70 batch with one apparatus, the B/C ratio of them was greater than 1, indicating that the production is economically feasible. The period to achieve a break-even point required to be 4 years in case of 100 and 80 batches to 5 years in case of 70 batch. But the private enterprises should operate at least two apparatus for the profits. Also, if the production was to be profitable, the prices of wood charcoals and pyroligneous liquid should be at least 750 won per kg and 700 won per liter.

• Physical Therapy Korea
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• v.15 no.2
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• pp.54-63
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• 2008

The purpose of this study was to examine the effect of the hip internal rotation on knee extensor and hip abductor electromyographic (EMG) activity during stair up and stair down mobility. Eighteen healthy subjects were recruited. All subjects performed stair up and down movements on a step of 30cm height while maintaining the hip in neutral (condition 1) and hip in internal rotation (condition 2). Surface EMG activity was recorded from five muscles (gluteus maximus, vastus lateralis (VL), vastus medialis oblique (VMO), posterior gluteus medius (Gmed), and tensor fascia latae (TFU)) and hip internal rotation angle was measured using a three dimensional motion analysis system The time period for stair up and down was normalized using the MatLab 6.5 program, and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities according to the hip rotation (neutral or internal rotation) during the entire time period of stair up and down in each phase were compared using a paired t-test. During the entire period of stair up, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). During the entire period of stair down, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). However, the EMG activities of the other muscles were not significantly different between the conditions (p>.05). These results suggest that the stair up and down maintaining hip internal rotation was could be a contributing factor on patellar lateral tracking.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.414-422
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• 2008

Adsorption experiments for $H_2$, $CH_4$, CO, $CO_2$ on activated carbon and zeolite 5A were performed by static volumetric method. A 4-bed pressure swing adsorption (PSA) process was to study separation of hydrogen from multi-component mixture gases ($H_2$ 72.2%, $CH_4$ 4.06%, CO 2.03%, $CO_2$ 21.6%). Dual-site langmuir (DSL) isotherm showed good or fair agreement with the experimental results. The optimum height of activated carbon layer was 55 cm with breakthrough results on the packing ratio of activated carbon to zeolite 5A. In PSA process, the effects of the process parameters such as total cycle time ($T_c$), ${\Delta}P$ at the provide purge step and adsorption pressure on the PSA performance were studied experimentally and theoretically.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.9
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• pp.825-837
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• 2017

This paper describes a novel type of a walking rehabilitation robot that applies robot technologies to crutches used by patients with walking difficulties in the lower body. The primary features of the developed robot are divided into three parts. First, the developed robot is worn on the patient's chest, as opposed to the conventional elbow crutch that is attached to the forearm; hence, it can effectively disperse the patient's weight throughout the width of the chest, and eliminate the concentrated load at the elbow. Furthermore, it allows free arm motion during walking. Second, the developed robot can recognize the walking intention of the patient from the magnitude and direction of the ground reactive forces. This is done using three-axis force sensors attached to the feet of the robot. Third, the robot can perform a stair walking function, which can change vertical movement trajectories in order to step up and down a single stair according to the floor height. Consequently, we experimentally showed that the developed robot can effectively perform walking rehabilitation assistance by perceiving the walking intention of the patient. Moreover we quantitatively verified muscle power assistance by measuring the electromyography (EMG) signals of the muscles of the lower limb.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.362-368
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• 2007

This study was conducted to estimate merchantable volume and yield per diameter (DBH) class of Pinus koraiensis and Larix kaempferi. Stem volume of trees in each diameter class was calculated using the existing equations for taper and height curve. Saw logs and pulpwood volume were then estimated from the stem volume in each diameter class. The final step was to estimate merchantable volume and yield from saw logs, assuming saw logs were used for lumber (boards or dimension products) production only. The results showed that the stem volume of Larix kaempferi was 23~38% higher than that of Pinus koraiensis at the same diameter classes. Both species were able to produce saw logs from the diameter class of 18 cm. Saw logs and pulpwood yield for both species rapidly increased due to the size limitation on small end diameter. This yield reached a maximum of 90% and 88% at 26 cm and 38cm diameter class, respectively, for Pinus koraiensis and Larix kaempferi. Lumber yield estimated for board products ranged from 23% to 56%. In the case of dimension products, Lumber yield became significantly smaller as saw logs were used for larger dimension products. These results can be used for calculating merchantable volume and economic value of trees, as well as determining final lumber products.

• Progress in Medical Physics
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• v.16 no.4
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• pp.176-182
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• 2005

Stereotactic radiosurgery (SRS) is a technique to deliver a high dose to a target region and a low dose to a critical organ through only one or a few irradiation. The SRS must be planned exactly. Currently the surgery plan is peformed by trial and error method. There are many questions about the reliability and reproducibility of the plan result. This study Improve each step of the Oh's method based on heuristic target shaping to obtain the better result. The target was reconstructed using cylinders with same height and the neighbored cylinders were combined according to the difference of each center and diameter. Then, spheres were packed within each cylinders by the packing rules. Two virtual targets were used to compare this method with Oh's method. As a result, the numbers of isocenter were successfully reduced - more than $35\%$ and $26\%$ - without serious differences of proscription isodose to tumour volume ratio (PITV) and maximum dose to proscription dose ratio (MDPD). This technique using cylinder piling and sphere packing will be a helpful tool to planner in stereotactic radiosurgery.