• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.385-386
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• 2002

Many important physical properties of natural or man-made aerosol particles such as light scattering, electrostatics charges, and toxicity, as well as their behavior involving physical processes like diffusion and thermophoresis depend strongly on their size distribution. Important aerosol behavior mechanisms affecting the size distribution of aerosol particles include condensation, deposition, and coagulation. (omitted)

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.21-24
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• 1998

Simulation modeling has become an extremely important approach to analyzing complex system. In recent years the number of people using simulation as problem-solving aid has increased. In this Paper, we developed a simulation model for analyzing the physical distribution system in ports. We used Arena 2.2 which is a kind of simulation software based common simulation language, SIMAN V. And then, we applied this model to kwangyang port(partially) and analyzed the effect of it upon port system in according to change of the quantity of goods transported.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.1
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• pp.37-48
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• 2005

Objects: This study is designed to analysis improvement and maintaince of trunk stability targeting patients who need post operative rehabilitation exercise after undergoing opened microscopic laser discectomy(OMLD) due to HNP. Method: Between March 2004 and February 2005 a total sixty patients who underwent OMLD due to $L_4/L_5$, $L_5/S_1$ HNP and who agreed to the experiment were subject for this study. Experimental group consisted of 18 subjects, and they underwent 45 minutes dynamic lumbar stabilization exercise And control group consisted of 18 subjects who conducted conservative physical therapy based on the use of physical modality for 45 minutes except to exercise. Results: Experimental group that was lumbar extensor's isometric peak torque, weight distribution of both leg, trunk muscle balance and Oswestry LBP disability index increased during 12 weeks in a statistically significant manner compared to before exercise (p<.05). When re-test was tried, isometric peak torque (p>.05) and Oswestry LBP disability index(p<.05) maintained 12th week level or improved. Weight distribution rate of both leg and trunk muscle balance maintained the level of 8th week of exercise execution(p<.05). Control group that was lumbar extensor's isometric peak torque, weight distribution rate of both leg and trunk muscle balance aggravated during 12 weeks compared to pre-test(p>.05) But, Oswestry LBP disability index increased in a statistically significant level compared to pre-test(p<.05). When re-test was tried, isometric peak torque increased slightly compared to pre-test, but decreased when at least $60^{\circ}$ flexion angle(p>.05). Weight distribution rate of both leg and trunk muscle balance also aggravated compared to pre-test(p>.05), and Oswestry LBP disability index was similar to the 4th week of physical therapy execution(p>.05). Conclusion: Successive postoperative Especially, Application of dynamic lumbar stabilization exercise program is important than traditional lumbar strengthening exercise program in the maintaince of spinal stability.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.225-233
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• 2004

Purpose: The Ideal breast irradiation method should provide an optimal dose distribution In the treated breast volume and a minimum scatter dose to the nearby normal tissue. Physical wedges have been used to Improve the dose distribution In the treated breast, but unfortunately Introduce an Increased scatter dose outside the treatment yield, pavllculariy to the contralateral breast. The typical physical wedge (FW) was compared with 4he virtual wedge (VW) to do)ermine the difference In the dose distribution affecting on the treated breast and the contralateral breast, lung, heart and surrounding perlpheral soft tissue. Methods and Materials: The data collected consisted of a measurement taken with solid water, a Humanoid Alderson Rando phantom and patients. The radiation doses at the ipsllateral breast and skin, contralateral breast and skin, surrounding peripheral soft tissue, and Ipsllateral lung and heart were compared using the physical wedge and virtual wedge and the radiation dose distribution and DVH of the treated breast were compared. The beam-on time of each treatment technique was also compared Furthermore, the doses at treated breast skin, contralateral breast skin and skin 1.5 cm away from 4he field margin were also measured using TLD in 7 patients of tangential breast Irradiation and compared the results with phantom measurements. Results: The virtual wedge showed a decreased peripheral dose than those of a typical physical wedge at 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, and 60$^{\circ}$. According to the TLD measurements with 15$^{\circ}$ and 30$^{\circ}$ virtual wedge, the Irradiation dose decreased by 1.35$\%$ and 2.55$\%$ In the contralateral breast and by 0.87$\%$ and 1.9$\%$ In the skin of the contralateral breast respectively. Furthermore, the Irradiation dose decreased by 2.7$\%$ and 6.0$\%$ in the Ipsllateral lung and by 0.96$\%$ and 2.5$\%$ in the heart. The VW fields had lower peripheral doses than those of the PW fields by 1.8$\%$ and 2.33$\%$. However the skin dose Increased by 2.4$\%$ and 4.58$\%$ In the Ipsliateral breast. VW fields, In general, use less monitor units than PW fields and shoriened beam-on time about half of PW. The DVH analysis showed that each delivery technique results In comparable dose distribution in treated breast. Conclusion: A modest dose reduction to the surrounding normal tissue and uniform target homogeneity were observed using the VW technique compare to the PW beam in tangential breast Irradiation The VW field is dosmetrically superlor to the PW beam and can be an efficient method for minimizing acute, late radiation morbidity and reduce 4he linear accelerator loading bV decreasing the radiation delivery time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.41-48
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• 2008

The purpose of this study was to investigate the job stress factors that were related to the general characteristics, work characteristics, and health characteristics of the workers at distribution industry. The survey of job stress measurement scale for Korean employee which was developed by KOSHA and OSHRI in 2003 was used for this study. Three hundred and fifty workers at distribution industry participated in this study, and among them 326 responses were analyzed for this study due to the unreliability and insincerity of responses. Eight job stress factors like physical environment, self-control for the job, job unsecure, organization system, workplace culture, compensation for the job, relationship to the superior, and job requirement were analyzed. The results showed that the stress because of self control for the job was relatively higher than that of other industry workers. However, the stress because of physical environment, job requirement, job unsecure, organization system and compensation for the job was relatively lower than that of other industry workers. The female workers felt more stress than male workers in compensation for the job and workplace culture factors at distribution industry. The delivery and carrying job workers were more stressful than those of other jobs at distribution industry because of physical environments and self-control for the job. The non-regular job workers were more stressful than regular job workers in many stress factors like self-control for the job, job unsecure, organization system and compensation for the job.

• Journal of Distribution Science
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• v.21 no.7
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• pp.73-82
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• 2023

Purpose: Social networking services have been recognized as an attractive distribution channel at a time when efforts to deliver effective messages to consumers are essential amid a flood of advertisements in the multi-media era. In that sense, this study investigated the effect of the scarcity message type (limited-time vs. limited-quantity) and sender type (corporate vs. consumer) on the intention to purchase golf equipment by Instagram distribution channel. Research design, data and methodology: Data from 108 college students in their 20s and 30s with experience using Instagram were collected online through convenience sampling. A frequency analysis, exploratory factor analysis, reliability analysis, independent sample t-test, and two-way analysis of variance were performed using SPSS 23.0. Results: The results showed that limited-quantity messages induce a higher purchase intention than limited-time messages. Similarly, consumer-sent advertisements induce a higher purchase intention than corporate-sent advertisements. Further, there is no statistically significant interaction effect of the scarcity message type and sender type on the intention to purchase golf equipment. Conclusions: This study is meaningful in verifying consumers' purchase intention depending on the type of scarcity message and the type of sender in Instagram advertisements. The results yield significant implications for marketers and several directions for future research.

• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.967-972
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• 2010

We shall consider estimations of an exponetiated parameter of the exponentiated Pareto distribution with known scale and threshold parameters. A quotient distribution of two independent exponentiated Pareto random variables is obtained. We also derive the distribution of the ratio of two independent exponentiated Pareto random variables.

• Physical Therapy Rehabilitation Science
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• v.3 no.2
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• pp.112-118
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• 2014

Objective: The purpose of this study was to investigate the effects of an exercise with and without neuromuscular electrical stimulation (NMES) of the quadriceps femoris muscle, on strength, pain, and weight distribution in patients with knee instability post surgery. Design: Randomized controlled trial. Methods: Twenty patients in the early stage of rehabilitation after knee surgery were recruited as subjects and were randomly divided into either experimental group (exercise combined with NMES) (n=10) or control group (n=10). Both groups received strength training of the lower limb for 20 min/day, 5 days/week for 4 weeks. The experimental group used NMES for unilateral quadriceps femoris training with incremental increases in the intensity of isometric contraction over 4 weeks. Outcome measurements were assessed using the digital manual muscle testing, 30-chair stand test (30CST), numeric pain rating scale (NPRS) and weight distribution using the foot analyzer before and after 4 weeks of training. Results: After the 4-week intervention, knee extensor strength increased significantly in the experimental group post intervention (p<0.05), and there was a significant improvement in the experimental group compared with the control group (p<0.05). The 30CST and NPRS scores improved significantly in the experimental group compared to the control group (p<0.05), and there was a significant difference between the two groups (p<0.05). Weight distribution was significantly improved in the experimental group compared with the control group, (p<0.05), but there was no significant difference in improvement between the two groups. Conclusions: This study showed that NMES combined with strengthening exercises of the lower limbs is effective in improving lower limb pain and strength in patients with instability after knee surgery.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.29-43
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• 2019

In recent years, as the network traffic in the WSN(Wireless Sensor Network) has been increased by the growing number of IoT wireless devices, SDWSN(Software-Defined Wireless Sensor Network) and its security that aims a secure SDN(Software-Defined Networking) for efficiently managing network resources in WSN have received much attention. In this paper, we study on how to efficiently and securely design a PUF(Physical Unclonable Function)-assisted group key distribution scheme for the SDWSN environment. Recently, Huang et al. have designed a group key distribution scheme using the strengths of SDN and the physical security features of PUF. However, we observe that Huang et al.'s scheme has weak points that it does not only lack of authentication for the auxiliary controller but also it maintains the redundant synchronization information. In this paper, we securely design an authentication process of the auxiliary controller and improve the vulnerabilities of Huang et al.'s scheme by adding counter strings and random information but deleting the redundant synchronization information.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.2
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• pp.53-62
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• 2022

PURPOSE: This study was conducted to investigate the effect of a real-time pressure feedback provided during gait training on the weight weight distribution of the inner part of mid-foot in paralyzed side and gait function in stroke patients. METHODS: A total of 24 patients with hemiplegic stroke in a rehabilitation hospital were randomly assigned to the experimental and control group. All participants (n = 24) performed 15 min of comprehensive rehabilitation therapy 5 times a week for a period of 4 weeks. Additionally, the experimental group and control group underwent gait training with a real time feedback and general gait training, respectively, for 15 min five times a week for 4 weeks. Weight distribution and gait function were measured before and after the 4-week training. RESULTS: Significant increases in the weight distribution (WD), stance time (ST) and step length (SL) of the paralyzed side, and a significant decrease in the 10 m walking test (10 MWT) observed after training in the two groups (p < .05). The experimental group showed larger changes in the all variables than the control group (WD, +10.5 kg vs. +8.8 kg, p < .05; ST, 12.8 s vs. 4.9 s, p < .05; SL, 4.9 cm vs. 1.7 cm, p < .05; 10 MWT, -3.5 s vs. -1.0 s, p < .05, respectively). CONCLUSION: Gait training with a real-time feedback might be effective in improving the normalization of weight bearing of the paralyzed lower extremity and gait function of stroke patients, and be considered to be a more effective gait training for improving the abilities than the general gait training.