• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.42 no.1
• /
• pp.45-55
• /
• 2016

Light shows various optical behaviors such as reflection, absorption, and scattering on skin for individuals. In particular, reflection of light from the skin has been widely used as the brightness index of the skin of individuals through the measurement of the physical quantity of spectral reflectance. Therefore, the study of light behavior on skin would be useful for the preparation of new evaluation method in the development stage of make-up products. In this study, multi-dimensional analysis for spectral reflectance behavior of light on individual skin was performed using Kubelka-Munk model. Also, we analyzed the contribution of skin parameters such as skin thickness and hemoglobin, which could affect the spectral reflectance, using above model and literature information. Base on this, we calculated the theoretical reflectance of normal women for visual light, which showed good agreement with the measured reflectance. Our study of light propagation in skin based on Kubelka-Munk model provides useful insight for the development of personalized cosmetic in the near future.

• Korean Security Journal
• /
• no.62
• /
• pp.87-111
• /
• 2020

Special security guards working at nuclear power plants, one of the country's major facilities, serve as human protection to safeguard from threats to nuclear facilities and nuclear materials. The purpose of this study was to develop a physical fitness program for fitness management that is essential for the completion of missions of special guards. This program was designed to prepare the physical fitness test proposed by Jeong et al. (2019). Researchers conducted literature analysis, research meetings, expert meetings and pretests, and developed a 90-minute physical fitness program for 6 weeks, 3 times a week. In order to verify the effectiveness of the developed physical fitness program, the experiment was conducted on 29 subjects(control group: 15, exercise group:14). Specifically, a six-week physical fitness program was conducted for exercise groups, and the fitness test for a special security guard was conducted for all subjects before and after the experiment. As a result, it was found that the physical fitness program was effective in improving the performance of 20m shuttle run, leg tuck, 20m sprint & carry, and medicine ball back throw. Until recently, problems of neglecting fitness management of security guards have been pointed out. It is expected that the physical fitness program proposed by this study will be a practical alternative for security guards' fitness management.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.3
• /
• pp.65-74
• /
• 2006

This study was attempted to Kinematical characteristics of the Endo $360^{\circ}$El-grip Swing on the horizontal bar. To do this, we selected and analyzed the performance of two athletes who did Endo $360^{\circ}$El-grip Swing in the horizontal bar competition of male artistic gymnastic in the 22nd Universiad Games 2003 Daegu. We drew the conclusions from the kinematical factors that were came out through analyzing three-dimensional cinematography of the athletes' movements, by using two video cameras. In point of analyzing the actual competition situation, it is expected that gymnastics and coaches have the effective informations, and the following conclusion had resulted. 1. When performing Endo $360^{\circ}$El-Grip, the average for entire required time was $1.93{\pm}0.06sec$. The average for descent phase time was $0.24{\pm}0.02sec$, ascent phase time was 0.22${\pm}0.07sec$, connecting phase time was $0.87{\pm}0.07sec$, and El-Grip phase time was $0.61{\pm}0.02sec$. The descent phase need short period of time but however to have a stable performance, ensuring ascent and connecting phase time are needed. El-Grip phase need short period of time to have a stable re-grasp. 2. To have a convenient preparation for El-Grip in descent and ascent phase, lowering CM, and ease up in sway and plunge from the High Bar would make descent and ascent even more faster and would have increase effect in trunk rotation. 3. In descent and ascent phase, if shoulder angle and arm slope is dwindling then it would effect rotation angle so might risk it from hitting a Bar when putting legs in and out. 4. In connecting phase, it requires some time to show stable performance when El-Grip phase is continued by using hip angle which would make trunk rotation angle bigger and make descent and ascent time slower. 5. In El-Grip phase, when doing motions like hand standing. using hip angle more than maximum would make CM even faster and it is stable position while performing.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.4
• /
• pp.77-87
• /
• 2008

This study is to formulate strategy for subject who are selected as national team in horizontal bars event in apparatus gymnastics. For this, skill training program was applied to players for 8 weeks. Then it was analyzed by using 3D motion Analysis system to seek the difference between before and after using the program. There were decisive demerit element K's first try for Tkatchev stretched movement from low elevation and crooked body while elevating. Not only, the location of his center of mass is far and low and there was some concern in his landing due to bended his hip-joint, but also, it exposed weak point in retro-action followed technique. Thus, to overcome that weak point, the subject repeated practices on following; when preparing for Tkatchev stretched movement at downward for big spin, make sure extend shoulder angle faster, make sure Tap movement is short and concise using hip-joint angular while delaying Tap timing for folding the body, and moreover, while backlashing the body, used shoulder joint angle wide to pull up the body. As a result, the speed of vertical upward did rut increase when separation from the bar. However, height of elevation increased that the leg would rut hit the horizontal bar even straight up the hip-joint. Therefore, the movement itself provided magnificent motion and even helped decrease the demerits.

• The Korean Journal of Mycology
• /
• v.45 no.4
• /
• pp.386-393
• /
• 2017

Onion downy mildew, caused by Peronospora destructor, is a major disease in onion cultivation areas in Korea. The causal fungi were collected and analyzed based on sequence similarity and molecular phylogenetic relationships of multi-gene sequences, including the internal transcribed spacer (ITS) region. All isolates from Changnyeong-gun, Hamyang-gun, and Hapcheon-gun in Gyeongnam province, and Muan-gun, Haenam-gun, and Sinan-gun in Jeonnam province were identical in the four types of gene sequences, indicating they were genetically the same strains. In this study, a PCR method was developed based on the ITS gene sequences to amplify the specific DNA fragment for P. destructor only. The detection limit of was total genomic DNA of the P. destructor and the plant $0.7ng/{\mu}L$. Therefore, the developed PCR method could be used to detect P. destructor effectively from symptomless onion leaves.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.6
• /
• pp.802-808
• /
• 2019

DC motors are used extensively on shipboard, including as the ship's winch operating motor, owing to their simple speed control and excellent output torque characteristics. Moreover, they were used as propulsion motors in the early days of electric propulsion ships. However, mechanical rectifiers, such as brushes, used in DC motors have certain disadvantages. Hence, brushless DC (BLDC) motors are increasingly being used instead. While the electrical characteristics of both types of motors are similar, BLDC motors employ electronic rectifying devices, which use semiconductor elements, instead of mechanical rectifying devices. The inverter system for driving conventional BLDC motors uses a two-phase excitation method so that the waveform of the back electromotive force becomes trapezoidal. This causes harmonics and torque ripple in the phase current switching period in which the winding wire through which the current flows is changed. Researchers have studied and presented various methods to reduce the harmonics and torque ripple. This study applies a cascaded H-bridge multilevel inverter, which implements a proportional-integral speed current controller algorithm in the driving circuit of the BLDC motor for electric propulsion ships using a power analysis program. The simulation results of the modeled BLDC motor show that the driving method of the proposed BLDC motor improves the voltage waveform of the input side of the motor and remarkably reduces the harmonics and torque ripple compared with the conventional driving method.

• Journal of Korean Neurosurgical Society
• /
• v.50 no.4
• /
• pp.332-340
• /
• 2011

Objective : Pyogenic spondylitis often results in acute neurological deterioration requiring adequate surgical intervention and appropriate antibiotic treatment. The purpose of this study was to conduct an analysis of the clinical effect of continuous irrigation via laminotomy in a series of patients with pyogenic spondylitis in thoracic and lumbar spine. Methods : The authors conducted a retrospective investigation of 31 consecutive patients with pyogenic thoracic and lumbar spondylitis who underwent continuous irrigation through laminotomy from 2004 to 2008. The study included 22 men and 9 women, ranging in age from 38 to 78 years (mean 58.1 years). The average follow-up duration was 13.4 months (range, 8-34 months). We performed debridement and abscess removal after simple laminotomy, and then washed out epidural and disc space using a continuous irrigation system. Broad spectrum antibiotics were administered empirically and changed according to the subsequent culture result. Clinical outcomes were based on the low back outcome scale (LBOS), visual analogue scale (VAS) score, and Frankel grade at the last follow-up. Radiological assessment involved plain radiographs, including functional views. Results : Common predisposing factors included local injection for pain therapy, diabetes mellitus, chronic renal failure, and liver cirrhosis. Causative microorganisms were identified in 22 cases (70.9%) : Staphylococcus aureus and Streptococcus spp. were the main organisms. After surgery, LBOS, VAS score, and Frankel grade showed significant improvement in most patients. Spinal stability was maintained during the follow-up period, making secondary reconstructive surgery unnecessary for all patients, except one. Conclusion : Simple laminotomy with continuous irrigation by insertion of a catheter into intervertebral disc space or epidural space was minimally invasive and effective in the treatment of pyogenic spondylitis. This procedure could be a beneficial treatment option in patients with thoracolumbar spondylitis combined with minimal or moderate destructive change of vertebrae.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.12
• /
• pp.1150-1158
• /
• 2010

In this study, the Polynomial-based Radial Basis Function Neural Networks is proposed as one of the recognition part of overall face recognition system that consists of two parts such as the preprocessing part and recognition part. The design methodology and procedure of the proposed pRBFNNs are presented to obtain the solution to high-dimensional pattern recognition problem. First, in preprocessing part, we use a CCD camera to obtain a picture frame in real-time. By using histogram equalization method, we can partially enhance the distorted image influenced by natural as well as artificial illumination. We use an AdaBoost algorithm proposed by Viola and Jones, which is exploited for the detection of facial image area between face and non-facial image area. As the feature extraction algorithm, PCA method is used. In this study, the PCA method, which is a feature extraction algorithm, is used to carry out the dimension reduction of facial image area formed by high-dimensional information. Secondly, we use pRBFNNs to identify the ID by recognizing unique pattern of each person. The proposed pRBFNNs architecture consists of three functional modules such as the condition part, the conclusion part, and the inference part as fuzzy rules formed in 'If-then' format. In the condition part of fuzzy rules, input space is partitioned with Fuzzy C-Means clustering. In the conclusion part of rules, the connection weight of pRBFNNs is represented as three kinds of polynomials such as constant, linear, and quadratic. Coefficients of connection weight identified with back-propagation using gradient descent method. The output of pRBFNNs model is obtained by fuzzy inference method in the inference part of fuzzy rules. The essential design parameters (including learning rate, momentum coefficient and fuzzification coefficient) of the networks are optimized by means of the Particle Swarm Optimization. The proposed pRBFNNs are applied to real-time face recognition system and then demonstrated from the viewpoint of output performance and recognition rate.

• Journal of Korean Medicine Rehabilitation
• /
• v.24 no.4
• /
• pp.117-127
• /
• 2014

Objectives The purpose of this study is to find out the relationship between the hip internal rotation angle and the site of herniation of single level lumbar intervertebral disc. Methods This study was carried out to 418 patients with lumbar disc herniation diagnosed by M.R.I, who visited Bu-Chun Jaseng Hospital of Korean Medicine with low back pain. Researchers measured their hip internal rotation angle and analyzed the relationship between the hip internal rotation angle and the site of herniation of single level lumbar intervertebral disc. Results 1. Excessive right internal rotation of hip joint increases risk of L5/S1 HIVD. 2. Limited left internal rotation of hip joint decreases risk of L4/L5 HIVD. 3. In cases of L4/L5 HIVD level, there was evidence that the prevalence of HNP in men was 1.85 times as higher than that in women. 4. In cases of L5/S1 HIVD level, there was the evidence that the prevalence of HNP in men was 0.64 times as lower than that in women. Conclusions In single-segment lumbar HIVD patients, limited left internal rotation of hip joint decreases risk of HIVD of L4/5 and excessive right internal rotation of hip joint mainly leads to L5/S1 HIVD.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.3
• /
• pp.6-12
• /
• 2011

The fast growing of the number of users requires the development of reliable communication systems able to provide higher data rates. In order to meet those requirements, techniques such as Multiple Input Multiple Out (MIMO) and Orthogonal Frequency Division multiplexing (OFDM) have been developed in the recent years. In order to combine the benefits of both techniques, the research activity is currently focused on MIMO-OFDM systems. In addition, for a fast wireless channel environment, the data rate and reliability can be optimized by setting the modulation and coding adaptively according to the channel conditions; and using sub-carrier frequency, and power allocation techniques. Depending on how accurate the feedback-based system obtain the channel state information (CSI) and feed it back to the transmitter without delay, the overall system performance would be poor or optimal. In this paper, we propose a Signal to Noise Ratio (SNR) estimation algorithm where the preamble is known for both sides of the transciever. Through simulations made over several channel environments, we prove that our proposed SNR estimation algorithm is more accurate compared with the traditional SNR estimation.