• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.1
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• pp.14-21
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• 2008

In this paper, we propose an adaptive contrast enhancement method using dynamic range segmentation. Histogram Equalization (HE) method is widely used for contrast enhancement. However, histogram equalization method is not suitable for commercial display because it may cause undesirable artifacts due to the significant change in brightness. The proposed algorithm segments the dynamic range of the histogram and redistributes the pixel intensities by the segment area ratio. The proposed method may cause over compressed effect when intensity distribution of an original image is concentrated in specific narrow region. In order to overcome this problem, we introduce an adaptive scale factor. The experimental results show that the proposed algorithm suppresses the significant change in brightness and provides wide histogram distribution compared with histogram equalization.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.92-97
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• 2015

The purpose of this work is to support a solution of optimizing TMO (tone mapping operator). JPEG XT Profile A and C utilize Erik Reinhard TMO that works well in most cases, however, detailed information of a scene is lost in some cases. Reinhard TMO only calculates its coefficient to have tone-mapping curve from log-average luminance, and this lead to lose details of bright and dark area of scenes in turn. Thus, this paper proposes an enhancement of the default TMO for JPEG XT Profile C to optimize tone-mapping curve. Main idea is that we divide tone mapping curve into several ranges, and set reasonable parameters for each range. By the experimental results, the proposed scheme shows and obtains better performance within a dark scene, compared to the default Reinhard TMO.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1445-1456
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• 2003

The ASTER TIR (thermal infrared radiometer) sensor has 5 spectral bands over 8 to 12 ${\mu}$m region. Rock type classification using the ASTER TIR nighttime data was performed in the Erta Ale range of the Ethiopian Rift Valley. Erta Ale range is the most important axial volcanic chain of the Afar region. The petrographic diversity of lava erupted in this area is very important, ranging from magnesian transitional basalt to rhyolites. We tried to classify the rock types based on the spectral behavior of each volcanic rock types in thermal infrared range and estimated SiO$_{2}$ content with emission data by the ASTER TIR.

• Journal of the Korean Home Economics Association
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• v.45 no.10
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• pp.97-111
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• 2007

This study examined the actual conditions of outdoor facilities and evaluated safety evaluations levels in playgrounds based on types of kindergartens. The samples for the survey were 100 kindergartens in Seongnam city Gyeonggi-Do province. Most outdoor facilities consisted of playgrounds with sand area and complex playing equipments, while wood-working area, sensory playing area, and mud playing area were less equipped than other facilities. In the case of outdoor playing facilities there were meaningful environmental differences within kindergartens. The public has less diversity in play areas and equipments and providing safety guidelines in playgrounds than privates. The score for the safety evaluations in the outdoor play environment was higher than average. As the range outdoor playing facilities increased, safety was dually considered, while kindergartens with a higher ratio of child-teacher numbers exhibited less consideration to playground safety.

• Journal of Fashion Business
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• v.14 no.3
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• pp.75-89
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• 2010

The purpose of this study is to provide information how to locate a apparel store based on target age, merchandise's type and price. Three trade areas in Seoul are chosen: Myeong-dong which is the biggest trade area in Korea; Kangnam station one of representative Kangnam trade areas; and Myeongil-Dong a neighborhood trade area. This study is mainly performed by analysing the locations of the stores in the given areas. The result shows that the main apparel stores in Myeong-dong are casual wear stores for young people with the range of mid-high price. The stores in Kangnam station trade area also sell the casual wear for young people but they are mostly mid-low priced. In the trade area of Myeongil-dong, however, there are various kinds of mid-priced apparel stores for residents of all ages. Apparel stores for formal wear, casual wear, and formal-casual wear tend to be located side by side. But other kinds do not. These results show that affinity is found in some types of apparel stores by the analysis of the next-door apparel stores.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.117-120
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• 2002

In this study the occlusion of dural-sac, the outer membrane of spinal cord in the lumbar region, was quantitatively analyzed using one motion segment finite element model. Occlusion was quantified by calculating cross sectional area change of dural-sac far different compressive impact duration(loading rate) due to bony fragment at the posterior wall of the cortical shell in vertebral body. Dural-sac was occluded most highly in the range of 8∼12 msec impact duration by the bony fragment intruding into the spinal canal. t=400 msec case 4% cross sectional area change was calculated, which is the same as the cross sectional area change under 6 kN of static compressive loading.

• Archives of Reconstructive Microsurgery
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• v.11 no.2
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• pp.162-166
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• 2002

The anterolateral thigh free flap was first reported by Song et al. in 1984 as a fasciocutaneous flap based on septocutaneous or musculocutaneous perforators of the lateral femoral circumflex vessel. It only becomes popular recently through confirmation of additional anatomy. For reconstruction of Achilles area defect, a thin flap is required to improve aesthetic and functional results. The anterolateral thigh free flap is relatively thin and can provide large skin area. It can be a useful option for reconstruction of Achilles area defect based on these characters. Since March 2002, we have successfully transferred 4 anterolateral thigh free flaps to reconstruct Achilles area defects and have attained good range of motion in this region. The anterolateral thigh free flap has many advantages and can be used for the reconstruction of Achilles tendon area defect.

• Atmosphere
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• v.16 no.2
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• pp.55-65
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• 2006

The characteristics of Depth-Area-Duration (DAD) for 50 storms over the Geumgang river basin have been analysed in terms of various storm causes using the precipitation data during the period from 1984 to 2003. Results show that the ratio of the precipitation depth to duration, and the ratio of decrease in the precipitation depth to area are the largest in the case of the tropical cyclone. Storm maximization ratios are in the range 1.03 to 2.66 for the 50 selected heavy precipitation cases over Geumgang river basin, with the largest value for the tropical cyclone case, suggesting that the tropical cyclone could cause heavier precipitation than the other storms. In addition, the 24-hour probable maximum precipitation for the Geumgang river basin is estimated to be about 745 mm in the maximum precipitation area.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2035-2040
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• 2004

A cone cylinder is used to obtain variable operation conditions for the sonic ejector-diffuser system. The cone cylinder is designed to move upstream and downstream to change the ejector throat area ratio, thus obtaining variable mass flow rates. The present study investigates the effects of ejector throat area ratio and operating pressure ratio on the entrainment of secondary stream for the variable sonic ejector system. In experiment, the ejector throat area is varied in the range from ${\psi}=11.88$ to 66.69, and the operating pressure ratio from $p_{0p}/p_a=1.25$ to 9.0. The results show that the variable sonic ejector system is suitable for a required entrainment ratio of secondary stream by altering the ejector throat area ratio and operating pressure ratio.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.414-417
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• 2004

A cone cylinder is used to obtain variable operation conditions for the sonic ejector-diffuser system. The cone cylinder is designed to be shifted upstream and downstream to change the ejector throat area ratio, thus obtaining variable mass flow rates. The present study investigates the effects of ejector throat area ratio and operating pressure ratio on the entrainment of secondary stream for the variable sonic ejector system. The study is carried out experimentally. The ejector throat area is varied at the range from Ψ= 11.88 to 66.69, and the operating pressure ratio is changed from $P_{op}$ / $P_{a}$=1.25 to 9.0. The results show that the variable sonic ejector system can be operated to obtain specific entrainment ratio of secondary stream by altering the ejector throat area ratio and operating pressure ratio.o.