• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.41-47
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• 2015

The bandwidth minimization problem (BMP) has been classified as NP-complete because the polynomial time algorithm to find the optimal solution has been unknown yet. This paper suggests polynomial time heuristic algorithm is to find the solution of bandwidth minimization problem. To find the minimum bandwidth ${\phi}^*=_{min}{\phi}(G)$, ${\phi}(G)=_{max}\{{\mid}f(v_i)-f(v_j):v_i,v_j{\in}E\}$ for given graph G=(V,E), m=|V|,n=|E|, the proposed algorithm sets the maximum degree vertex $v_i$ in graph G into global central point (GCP), and labels the median value ${\lceil}m+1/2{\rceil}$ between [1,m] range. The graph G is partitioned into subgroup, the maximum degree vertex in each subgroup is set to local central point (LCP), and we adjust the label of LCP per each subgroup as possible as minimum distance from GCP. The proposed algorithm requires O(mn) time complexity for label to all of vertices. For various twelve graph, the proposed algorithm can be obtains the same result as known optimal solution. For one graph, the proposed algorithm can be improve on known solution.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.77-85
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• 2015

This paper proposes a location algorithm that locates newly built p-facilities in the optimal area with minimum cost in a city of n districts. This problem has been classified as NP-hard, to which no polynomial time algorithm exists. The proposed algorithm improves the shortcomings of existing Myopic algorithm by constructing until p-facilities and exchanging locations of p-th facility for p=[1, n-1]. When applied to experimental data of n=5, 7, 10, 55, the proposed algorithm has obtained an approximate value nearest possible to the optimal solution take precedence of reverse-delete method. This algorithm is also simply executable using Excel.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1133-1146
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• 2016

Counts or averages over arbitrary regions are often analyzed using conditionally autoregressive (CAR) models. The spatial neighborhoods within CAR model are generally formed using only the inter-distance or boundaries between the sub-regions. Kyung and Ghosh (2009) proposed a new class of models to accommodate spatial variations that may depend on directions, using different weights given to neighbors in different directions. The proposed model, directional conditionally autoregressive (DCAR) model, generalized the usual CAR model by accounting for spatial anisotropy. Bayesian inference method is discussed based on efficient Markov chain Monte Carlo (MCMC) sampling of the posterior distributions of the parameters. The method is illustrated using a data set of median property prices across Greater Glasgow, Scotland, in 2008.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.184-190
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• 2012

Objectives: This study aimed to characterize the nanoparticles produced by welding and grinding processes. Methods: The number concentrations of particles were mapped to determine the distribution of welding fumes in a workplace atmosphere using a hand-held condensation particle counter. An electrical low-pressure impactor was used for measuring the number concentration and particle size distribution. Results: High number concentrations were found around arc cutting and welding (grinding) processes. In the worker's breathing zone, the mean number concentration was 655,000 particles/cm3 and the count median diameter (CMD) was 84 nm with several multi peak distributions (~20, 70, 300 nm). However, at a distance of 3 m from the welding position, the number concentration decreased to 153,000 particles/cm3 with a 70 nm single peak size distribution. During a grinding process, peaks with high concentrations of nanoparticles were temporarily observed. The mean number concentration was 1,520,000 particles/cm3, and the CMD was 30 nm. Nanoparticles (<100 nm) made up 58% and 92% of the aerosols produced by welding and grinding processes, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.1
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• pp.70-76
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• 2019

Ultra Wideband (UWB) Radar is a high-resolution radar for short distance detection which uses signals transmitted and received by each antennas in order to detect a target. It is possible to detect the respiration and heartbeat of a person without contact It is getting more and more often utilized since it is not affected by physical environment. In this paper, we implement an algorithm to detect human respiration and heartbeat rate using UWB radar signal. We process radar signals reflected from human body using Median filter, Kalman filter, Band Pass filter and so on. We also use CZT to extract breathing and heart rate. ECG (Electrocardiogram) was used for comparison of heartbeat data and we confirm that each data of ECG and UWB Radar were more than 98% identical each other.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.39-45
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• 2021

An experiment to visualize fine dust captured by FOG droplet is conducted. Coal dust with 23.56 MMD (Mean Median Diameter) and water with 17.02 MMD is used as fine dust and FOG droplet. Long distance microscope and high-speed camera are used to capture the images of micro-scale particles sprinkled by acrylic duct. After measuring and comparing the size of the coal dust and FOG droplet to MMD, process to seize the coal dust with FOG droplet is recorded in 2 conditions: Fixed and Floated coal dust in the floated FOG droplet flow. In both conditions, a coal dust particle is collided and captured by a FOG droplet particle. A FOG droplet particle attached at the surface of the coal dust particle does not break and remains spherical shape due to surface tension. Combined particles are rotated by momentum of the particle and fallen.

• The Journal of Korean Medicine
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• v.44 no.4
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• pp.193-207
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• 2023

Objectives: The purpose of this study was to evaluate the effectiveness and safety of traditional herbal medicine as a stand-alone treatment group through major English databases due to the lack of RCTs in Korea, and to provide a review of the herbal interventions used. Methods: Using four databases (Pubmed, EMBASE, OASIS, RISS), combination of words such as "Coronavirus" "RCT" "Herb" "Decoction" "TCM" were used. RCTs using herbal medicines to treat coronavirus were searched. Final 4 studies were selected by two authors according to inclusion and exclusion criteria. Results: A total of 1,435 patients were studied. The Chinese herbs used in the treatment group were Shengmai Yin, JingYinGuBiao granules, Jinhua Qinggan granules, and Bufei Huoxue capsules. The intervention group showed greater attenuation of pneumonia lesions on CT. Also, improvement in 6-min walk distance (6MWD), and negative conversion rate in treatment group were reported. Furthermore, scores on the Fatigue Assessment Inventory (FAI) were lower in the herbal group than in the placebo group. The median time to recovery of COVID-19 related symptoms was shorter in TCM group compared to the control group. Reported adverse effects were diarrhea, liver dysfunction, and excessive menstruation, and two papers did not mention side effects in detail. Conclusion: Herbal medicine alone can increase the conversion rate of viral negativity and relieve COVID-19 related symptoms without significant adverse effects.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.98-103
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• 2010

Purpose: We reported the results of arthroscopically assisted lateral release and medial imbrication for the recurrent patella dislocation. Materials and Methods: Twenty patients (20 knees) underwent arthroscopically assisted surgery for the recurrent patella dislocation. There were 4 males and 16 female. The average age was 20.2 years. All patients had definite trauma history and average follow-up period was 19 months. The surgical results were evaluated according to the Lysholm knee score and the Kujala score. The congruence angle and lateral patellofemoral angle were measured on plain radiograph and the tibial tubercle-trochlear groove distance was calculated on computerized tomography. Results: The median value of preoperative congruence angle was $16.5^{\circ}$ (range, $0.0{\sim}+34^{\circ}$) and the average final follow-up was $-6.4^{\circ}$ (range, $-19{\sim}10^{\circ}$) with statistically significant improvement (p=0.025). The median value of preoperative Lysholm knee score was 70 (range, 63~81) and the final follow-up score had changed to 88 (range, 80~95) with statistically significant improvement (p=0.0341). The median value of preoperative Kujala score was 72 (range, 65~80) and the average final follow-up score showed 87 (range, 80~92) with statistically significant improvement (p=0.024). Recurrent dislocations after surgery occurred in 2 cases, one case which showed positive "thumb to forearm test" had been treated with medial patellofemoral ligament reconstruction. Conclusion: Arthroscopically assisted lateral release and medial imbrication for recurrent patella dislocation without bony malaligmenent showed the effective treatment, but would be inappropriate for the patients with the generalized joint laxity.

• Journal of Environmental Science International
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• v.24 no.7
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• pp.875-882
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• 2015

In 2013, International Agency for Research on Cancer (IARC) concluded that outdoor air pollution is carcinogenic to humans, with the particulate matter component of air pollution most closely associated with sufficient evidence of increased cancer incidence by exposure to particulate matter component of air pollution. Motor vehicles are one of a major emission sources of fine particle ($PM_{2.5}$) in urban areas. A large number of epidemiological studies have reported a positive association of morbidity or mortality with distance from the roadside. We conducted this study to assess the association of $PM_{2.5}$ concentrations measured at roadside hotspots with those at adjacent residential sites using real-time $PM_{2.5}$ monitors. We conducted real-time $PM_{2.5}$ measurements for rush hour periods (08:00~10:00 and 18:00~20:00) at 9 roadside air monitoring Hotspot sites in metropolitan Seoul over 3 weeks from October 1 to 21, 2013. Simultaneous measurements were conducted in residential sites within a 100 m radius from each roadside air monitoring site. A SidePak AM510 was used for the real-time $PM_{2.5}$ measurements. Medians of roadside $PM_{2.5}$ concentrations ranged from $9.8{\mu}g/m^3$ to $38.3{\mu}g/m^3$, while corresponding median values at adjacent residential sites ranged from $4.4{\mu}g/m^3$ to $37.3{\mu}g/m^3$. $PM_{2.5}$ concentrations of residential sites were 0.97 times of hotspot roadside sites. Distributions of $PM_{2.5}$ concentrations in roadside and residential areas were also very similar. Real-time $PM_{2.5}$ concentrations at residential sites, (100 m adjacent), showed similar levels to those at roadside sites. Increasing the distance between roadside and residential sites, if needed, should be considered to protect urban resident populations from $PM_{2.5}$ emitted by traffic related sources.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.111-126
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• 1998

In this study, radiographic evaluation was made using panoramic radiography and cross-sectional tomography of SCANORA/sup (R)/ in male and female adults in their 20's on the relationship between the maxillary sinus floor and the apex of the maxillary molar, to test the accuracy and effectiveness of the cross-sectional tomography, and to use this information in the assessment of preop. and postop. root canal treatment, apical surgery, extraction and implantology. Forty-one adults with an average age of 24.4 years were studied using panoramic radiography and cross-sectional tomography. In panoramic view and cross-sectional view, the position of the apices of maxillary molars were classified as separated, contacted, or protruded type; the general shape of the maxillary sinus floor was evaluated horizontally and vertically from cross-sectional tomography. The accuracy of each radiography was tested using maxilla from 5 fresh cadavers from the Anatomy Lab at Yonsei University Dental College, and panoramic view and cross-sectional tomography were taken in the same condition as with the patients. The results were as follows: 1. Panoramic view and cross-sectional view were taken in the maxilla specimen, and the actual distance between the maxillary sinus floor and the tooth apices were measured in the specimen; the median values of the distance from the tooth apices to the maxillary sinus floor in the panoramic view, cross-sectional view and in the actual maxilla specimen were 2.83 mm, 4.51mm, and 4.l5mm, respectively. In the cross-sectional view, the measured distance was close to the actual distance but in the panoramic view, the measured distance was far from the actual distance. 2. When the results of the panoramic view and cross-sectional view were compared, 40.5％ of the results agreed with each other in the two radiographic methods and buccal roots of the 2nd molar were the closest to the maxillary sinus floor in the cross-sectional tomography. 3. In cross-sectional view, when the vertical relationship of the maxillary sinus floor and maxillary roots was assessed, in 1st molars, type II (the sinus floor that extends down to the buccolingual furcation area) was predominant, while in 2nd molars, type I (the sinus floor located above the level connecting the buccal and lingual apices) was predominant. In the horizontal relationship, in 1st molars, type II (the lowest floor of the maxillary sinus located in between the buccal and lingual roots) was predominant; in 2nd molars, type I (the lowest floor of the maxillary sinus located on the buccal side of the buccal roots) and type II appeared in similar frequency. In conclusion, the SCANORA/sup (R)/ cross-sectional tomography was more effective than the frequently used panoramic view, in that the relationship of the maxillary molars and maxillary sinus floor can be evaluated more accurately and the buccolingual cross-sectional view can also be observed. And maxillary sinus floor that was close to maxillary 2nd molar had tendency to be located on buccal side than that close to 1st molar. Therefore, cross-sectional tomography is an effective and accurate method to evaluate the position of the teeth in relation to the sinus floor preoperative and can be easily used to diagnose localized periapical lesions. Also, the image quality obtained was quite satisfactory.