• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.109-119
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• 2011

In this study, the flow characteristics of Han River Estuary were investigated by using a two-dimensional numerical model according to the assumption of shift and modification of the Shingok submerged weir. The two-dimensional analysis has contributed to our understanding of the hydraulic effects induced by shift of the weir on the topography, especially wetlands. The tide and flow discharge of 2007 were adopted as an input data for the simulation. The tidal data contained both spring and neap tide, and the flow discharge condition was divided into monsoon and normal seasons. The boundaries of this study were Hangang Bridge, Tongil Bridge, and Yu island. The simulation results showed that influence area of seawater changed depending on the weir shift, and the water level at particular station fluctuated according to the condition of tide and flow discharge.

• Safety and Health at Work
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• v.13 no.1
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• pp.9-16
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• 2022

Background: The global shift toward greener societies demands new technologies and work operations in the waste-management sector. However, progressive industrial methods do not necessarily consider workers' health. This study characterized workers' exposure to bioaerosols and investigated the bioaerosols' potential to engage the immune system in vitro. Methods: Full shift personal aerosol sampling was conducted over three consecutive days. Dust load was analyzed by gravimetry, fungal and actinobacterial spores were analyzed by scanning electron microscopy, and endotoxin by limulus amebocyte lysate (LAL) assay. In vitro exposure of HEK cells to airborne dust samples was used to investigate the potential of inducing an inflammatory reaction. Results: The total dust exposure level exceeded the recommended occupational exposure limit (OEL) of 5.0 mg/m³ in 3 out of 15 samples. The inhalable endotoxin level exceeded the recommended exposure level by a 7-fold, whereas the fungal spore level exceeded the recommended exposure level by an 11-fold. Actinobacterial spores were identified in 8 out of 14 samples. In vitro experiments revealed significant TLR2 activation in 9 out of 14 samples vs. significant TLR4 activation in all samples. Conclusion: The present study showed that the dust samples contained potentially health-impairing endotoxin, fungi, and actinobacterial levels. Furthermore, the sampled dust contained microbial components capable of inducing TLR activation and thus have the potential to evoke an inflammatory response in exposed individuals.

• International Journal of Highway Engineering
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• v.7 no.1 s.23
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• pp.49-61
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• 2005

The dynamic modulus of hot mix asphalt can be determined according to the different combinations of testing temperature and loading frequency. The superposition rule is adapted to get the master curve of dynamic modulus for each hot mix asphalt. There are couple of different methods to get the shift factor which is a key for making the master curve. In this paper, Arrehnius, 2002 AASHTO, and experimental method was employed to get the master curve. Evaluation of dynamic modulus for 25mm base course of hot mix asphalt with granite aggregate and two asphalt binders(AP-3 and AP-5) was carried out. Superpave Level 1 Mix Design with gyratory compactor was adopted to determine the optimum asphalt binder content(OAC) and the measured ranges of OAC were between 4.1% and 4.4%. UTM was used for laboratory test. The dynamic modulus and phase angle were determined by testing on UTM, with 5 different testing temperature(-10, 5, 20, 40, & $55^{\circ}C$) and 5 different loading frequencies(0.05, 0.1, 1, 10, 25 Hz). Using the measured dynamic modulus and phase angle, the input parameters of Sigmoidal function equation to represent the master curve were determined and these will be adopted in FEM analysis for asphalt pavements. The shift factor and activation energy for determination of master curve were calculated.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.57-63
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• 1984

To assess the hearing conservation by the hearing protection devices in the field, 1,237 healthy female weavers of 16 to 24 year old were surveyed from April 1982 to January 1983. By reviewing the charts, their working durations, hearing threshold shift levels and whether wearing the ear plugs or not were checked. The hearing threshold levels were measured at 4,000Hz by audiometry AA-30A, RION Japan. They were divided into two groups: an experimental group with ear plug and the control group without it. The threshold shift level above 40dB in controls was 44.6% in left and 40.9% in right ear and that in experimental group 8.0% in left and 6.6% in right ear. The distribution of threshold shift levels between control and experimental group was significantly different in both ears, but that between left and right ear not significantly different in both groups. The longer the working durations were, the more the proportion of high threshold shift levels was and the larger the differences in the proportion of above 40dB between both groups were.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.39-46
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• 2007

Research on human identification in ubiquitous environment has recently attracted a lot of attention. As one of those research, gait recognition is an efficient method of human identification using physical features of a walking person at a distance. In this paper, we present a human shape extraction and tracking for gait recognition using geodesic active contour models(GACMs) combined with mean shift algorithm The active contour models (ACMs) are very effective to deal with the non-rigid object because of its elastic property. However, they have the limitation that their performance is mainly dependent on the initial curve. To overcome this problem, we combine the mean shift algorithm with the traditional GACMs. The main idea is very simple. Before evolving using level set method, the initial curve in each frame is re-localized near the human region and is resized enough to include the targe region. This mechanism allows for reducing the number of iterations and for handling the large object motion. The proposed system is composed of human region detection and human shape tracking modules. In the human region detection module, the silhouette of a walking person is extracted by background subtraction and morphologic operation. Then human shape are correctly obtained by the GACMs with mean shift algorithm. In experimental results, the proposed method show that it is extracted and tracked efficiently accurate shape for gait recognition.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.673-676
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• 2005

In this paper, we proposed the electric circuit using one common arm of H-Bridge Inverters to reduce the number of switching component in multi-level inverter combined with H-Bridge Inverters and Transformers. and furthermore we suggested the new multi-level PWM inverter using PWM level to reduce THD(Total Harmonic Distortion). and we used the switching method that can be same rate of usage at each transformer. Also, we tested the proposed prototype 9-level inverter to clarify the proposed electric circuit and reasonableness of control signal for the proposed multi-level PWM inverter.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1477-1479
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• 2005

In this paper, we proposed the electric circuit using one common arm of H-Bridge inverters to reduce the number of switching component in multi-level inverter combined with H-Bridge Inverters and Transformers. and furthermore we suggested the new multi-level PWM inverter using PWM level to reduce THD(Total Harmonic Distortion) and we used the switching method that can be same rate of usage at each transformer. Also, we tested the proposed prototype 15-level inverter to clarify the proposed electric circuit and reasonableness of control signal for the proposed multi-level PWM inverter.

• Quality Improvement in Health Care
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• v.11 no.1
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• pp.16-30
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• 2004

Background: Although the number of cancer patients increase, the resources for cancer management are not increased. If the outpatient chemotherapy administration room is operated, the shift of patients from inpatient 10 outpatient is occurred. So the capacities for chemotherapy increased and the shifted rooms were occupied with new non-chemotherapy patients. The income of the hospital increased. The purpose of this study was to assess usefulness and cost-effectiveness of the outpatient-chemotherapy adminstration model. Method: There are six beds, two chairs and two nurses and one personnel in the outpatient chemotherapy room. The satisfaction study by patients/family and doctors and the cost analysis over 12 months, by comparing costs of chemotherapy administration at outpatient chemotherapy room with inpatient at ward and inpatient-nonchemotherapy at ward were done. Results: The 97.1 percent of patients/family and the 94.4 percent of doctor who involved chemotherapy were satisfied with outpatient chemotherapy administration. The 91.7% of doctors said there were no differences in treatment outcome between outpatient and inpatient chemotherapy administration. The average number of patients in outpatient chemotherapy room increased from 10.7 to 15.4 but in inpatient from 19.4 to 18.3. The average number of inpatient chemotherapy were not changed related to increase of the average number of outpatient chemotherapy. The profit between outpatient chemotherapy and inpatient chemotherapy administration was 45,344,710 won and the profit between outpatient chemotherapy and non chemotherapy treatment was -185,294,614 won. Conclusion: The outpatient chemotherapy administration model is good for patients/family, doctors and hospital partially. But the hypothesis described above was not correct. The process of cancer patients treatment were from diagnosis and treatment to first administration of chemotherapy. So the shift from inpatient to outpatient was not occurred. In economic aspect, the profit between outpatient chemotherapy and non chemotherapy treatment was in the red. As the level of health care fees was so low, the hospitals hesitate operating the room of outpatient chemotherapy. It is necessary to raise the level of health case fees for outpatient chemotherapy administration.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.3
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• pp.280-288
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• 2016

Greenhouse gas (GHG) emissions have given rise to climate change which is one of the most serious environmental challenges that the world faces today. In response, Republic of Korea has proposed "Low Carbon, Green Growth" as a new economic paradigm accompanying with the ultimate aim of building a sense of responsibility for the environment. Korean government has set the ambitious national GHG emission reduction target which aims 37% reduction in the business-as-usual (BAU) level of 2030. The transportation sector plays a key role in this target. In the transportation sector, the GHG reduction target of 34.3% in the BAU level by 2020 has been allocated in order to consider the industrial specificity. Furthermore, it is known that the GHG reduction in the transportation sector has relatively minimal side effects compared to those of other sectors. In order to meet this national GHG reduction target, Korean government has set $CO_2$ emission regulation of vehicle for 2020. The purpose of this study is to evaluate the reduction effects by the average GHG regulation of vehicles. $CO_2$ emissions, between 2009 and 2013 were analysed by reduction measure such as technology improvement, light-weight, segment shift, diesel vehicle sales. During this period, $CO_2$ of vehicle was reduced every year by 19.9 g/km (i.e., 3.3% reduction per year). $CO_2$ reduction of imported vehicle is greater than domestic vehicle because of segment shift toward small size vehicle and higher diesel vehicle sales.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.3
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• pp.434-442
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• 2018

In this paper, we propose a road lane color recognition method from the image obtained from a driving vehicle. In autonomous vehicle techniques, lane information becomes more important as the level of autonomous driving such as lane departure warning and dynamic lane keeping assistance is increased. In particular the lane color recognition, especially the white and the yellow lanes, is necessary technique because it is directly related to traffic accidents. In this paper, color information of lane and road area is mapped to a 2-dimensional S-color space based on lane detection. And the center of the feature distribution is obtained by using an improved mean-shift algorithm in the S-color space. The lane color is determined by using the distance between the center coordinates of the color features of the left and right lanes and the road area. In various illumination conditions, about 97% color recognition rate is achieved.