• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.795-804
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• 2014

Objectives: The purpose of the study was to investigate the relationship between the oral contraceptive pill and periodontal disease in Korean women aged from 19 to 50 years old. Methods: This study selected 1,579 women of childbearing age from 19 to 50 years old from the 5th National Health and Nutrition Survey data analysis(phase 3, 2012) taking the oral examination. The questionnaire consisted of socioeconomic demographic characteristics, health behavior, use of oral contraceptive pills, and periodontal disease. Socioeconomic demographic characteristics included age, marital status, education, monthly income, and vocation. The health behavior included obesity, stress, smoking, subjective oral health status, use of dental floss, tooth brushing, and diabetes mellitus by fasting blood sugar level. Use of oral contraceptive pills was recorded by monthly use and duration. The periodontal disease was documented by yes or no and selected as dependent variable by logistic regression analysis. Results: After revising the taking period of oral contraceptive pill for this study, there was the correlation between the prevalence of periodontal disease and odds ratio(95% CI) 1.288(1.027-1.617). Conclusions: This study will contribute to the direction of policy for an oral contraceptive pill and provide the basic data for counseling for the oral health and the side effects of oral contraceptive pills.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.458-465
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• 2010

Hundreds of Steller sea lions, Eumetopias jubatus, migrate from Sakhalin and the northern Kuril Islands to Hokkaido every winter. During this migration, they may use their roaring sounds to navigate and to maintain their groups. We recorded the roars of wild Steller sea lions that had landed on reefs on the west coast of Hokkaido, and those of captive sea lions, while making video recordings. A total of 300 roars of wild sea lions and 870 roars of captive sea lions were sampled. The fundamental frequency ($F_0$), formant frequency ($F_1$), pulse repetition rate (PRR), and duration of syllables (T) were analyzed using a sonagraph. $F_0$, $F_1$, and PRR of the roars emitted by captive sea lions increased in the order male, female, and juvenile. By contrast, the $F_1$ of wild males was lower than that of females, while the $F_0$ and PRR of wild males and females did not differ statistically. Moreover, the $F_0$ and $F_1$ frequencies for captive sea lions were higher than those of wild sea lions, while PRR in captive sea lions was lower than in wild sea lions. Since there was a linear relationship between body length and the $F_0$ and $F_1$ frequencies in captive sea lions, the body length distribution of wild sea lions could be estimated from the $F_0$ and $F_1$ frequency distribution using a regression equation. These results roughly agree with the body length distribution derived from photographic geometry. As the volume of the oral cavity and the length of the vocal cords are generally proportional to body length, sampled roars can provide useful information about a population, such as the body length distribution and sex ratio.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4411-4431
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• 2014

Mobile ad hoc networks (MANETs) have recently gained increased interest due to the widespread use of smart mobile devices. Group communication applications, serving for better cooperation between subsets of business members, become more significant in the context of MANETs. Multicast routing mechanisms are very useful communication techniques for such group-oriented applications. This paper deals with multicast routing problems in terms of stability and scalability, using the concept of stable core. We propose LMRSC (Lightweight Multicast Routing Based on Stable Core), a lightweight multicast routing technique for MANETs, in order to avoid periodic flooding of the source messages throughout the network, and to increase the duration of multicast routes. LMRSC establishes and maintains mesh architecture for each multicast group member by dividing the network into several zones, where each zone elects the most stable node as its core. Node residual energy and node velocity are used to calculate the node stability factor. The proposed algorithm is simulated by using NS-2 simulation, and is compared with other multicast routing mechanisms: ODMRP and PUMA. Packet delivery ratio, multicast route lifetime, and control packet overhead are used as performance metrics. These metrics are measured by gradual increase of the node mobility, the number of sources, the group size and the number of groups. The simulation performance results indicate that the proposed algorithm outperforms other mechanisms in terms of routes stability and network density.

• Korean Journal of Head & Neck Oncology
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• v.10 no.2
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• pp.112-121
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• 1994

During the 7 years period from March 1987 to Febrary 1994, 344 patients with thyroid nodules, were admitted and operated at Department of Surgery, Collage of Medicine, Hallym university. We obtained following results: 1) The thyroid nodules were prevalent in female with ratio 1:17.1, both benign and malignant nodules were prevalent in the forth decade(37.8%:25.8%). 2) The duration of illness within 6 months was most common: 47.1% and within 1 years was 66.6%. 3) The most prominent symptoms & sign were palpable mass in anterior neck(96.8%). 4) The right-sided thyroid nodules were most common. 5) Thyroid scaning and thyroid function test were found to be not much value in differentiating malignancy. 6) Accuracy of the fine needle aspiration cytology was 75.5%. 7) There were 251 cases(73.0%) of benign and 93 cases(27.0%) of malignant nodules: most frequent benign nodule was adenomatous goiter(67.7%) and the most frequent malignant nodule was papillary adenocarcinoma (86.0%). 8) The most commonly performed surgical procedure was unilateral lobectomy with isthmectomy in both benign(41.0%) and malignant(33.3%). 9) Postoperative complications are as follows: transient hypothyroidism 22cases, transient hoaseness 16 cases, hypothyroidism 6 cases, wound infection 4 cases, hematoma 3 cases, permanent hoaseness 2 cases.

• Korean Journal of Head & Neck Oncology
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• v.10 no.2
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• pp.122-127
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• 1994

One hundred fifty four cases of branchial anomaly treated from January 1987 to July 1993 were analysed to determine clinical features, embryologic and anatomic types of the branchial cleft anomaly, to investigate the differences between adults and pediatrics, and to establish the appropriate treatment plan. The male to female ratio was not signifiacntly different in pediatric and adult patients. The mean symptom duration was 0.5 years(range 0.08-14 years) in pediatric patients and 1.67 years (0.7-7 years) in adult patients. The clinical presentations of these anomalies were lateral neck mass in 112(72.7%), infected discharge in 22(14.3%), non-infected discharge in 6(3.9%), and abscess in 14 cases(9.l%). Sites of the lesions were upper third of the neck in 93(60.3%), infraauricular in 35(22.7%), middle third of the neck in 17(11.0%) and inferior third of the neck in 9 cases(5.8%). The anatomic types were cystic form in 117(75.9%), sinus in 24(15.5%), and fistula in 13 cases(8.4%). Embryologic classification were 124 second branchial cleft anomalies(80.5%), 29 first branchial cleft anomalies(18.8%), and 1 third branchial cleft anomaly(0.6%). Immediate surgery under the uncontrolled infection in 17 cases result in 82.4% recurrent rate(14 cases), and 17.6% cure rate(3 cases). Delayed surgery under the controlled infection in 8 cases recurrent rate(1 case), and 87.5% cure rate(7 cases). In summary, the most common branchial cleft anomaly is second type cyst both in pediatric and adult group, delayed surgical exterpation after infection control with I & D or antibiotics may give a good chance for care and may reduce the recurrence.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.99-107
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• 1984

The auther studied clinically and. radiologically 48 cases which had been diagnosed as TMJ ankylosis in SNUDH (1974-1984). The purpose of this study is to analyse clinical features of TMJ ankylosis and to evaluate the effect of TMJ ankylosis on the growth of the mandible. The obtained results were as follows: 1. Total 48 cases of TMJ ankylosis patients consist of 23 males and 25 females. 65 percent of all cases of TMJ ankylosis occurred in patients between 1 and 10 years of age. The awerage age at the onset of ankylosis was 11.7 and average duration at the time of examination was 11.7 years. 2. Unilateral akylosis (81.3%) was more frequent than bilateral ankylosis (18.7%). 3. Traum a (57.9%) and infection (21.2%) were main etiology. 4. Inability to open the mouth (78.3%) and facial asymmetry (17.4%) were main chief complaints. 5. Mandibular morphology through radiographic features. (a) In TMJ ankylosis patients the ramus length of the ankylosed side was shorter than that of the non-ankylosed side. Comparing with the centrol group, ramus length of the each side was shorter than normal value. (b) The partial body length of the ankylosed side was longer than that of the non-ankylosed side. Comparing with the control group, partial body length of the each side was longer than normal value. Partial body length was related with antegonial notch depth. (c) Ratio of upper and lower ramus length at the level of mandibular foramen was smaller in ankylosed side than in non-ankylosed side. (d) Antegonial notch depth and ramus posterior contour depth were deeper in ankylosed side than in non-ankylosed side and those of both sides were deeper than normal value. (e) Gonial angle in ankylosed side was larger than in non-ankylosed side and that in both sides was smaller than normal value.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.162-168
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• 2007

Oral and maxillofacial infection is the oldest and most common disease in human history. The infection ranges from the low-grade infection that only requires minimal treatment to the high-grade and life-threatening fascial space infection. In this study, the data on oral and maxillofacial infections were analyzed to aid in the diagnosis and treatment, and to predict the prognosis. This report was based on data from 831 patients with oral and maxillofacial infection (394 males and 437 females) who were hospitalized in the Department of Oral and Maxillofacial surgery of Chosun University Dental Hospital from January 1998 to May 2005. The ratio of males to females was 0.9:1. By age, patients between 60 and 70 years old were the greatest in number (17.1%), while only 5.9% of the patients were between 10 and 20 years old. The most common cause of infection was odontogenic origin (84.4%), followed by post-extraction infection (6.2%), unknown (5.9%), and trauma (3.5%). The most common fascial space involved was the buccal space (39.4%), followed by the canine (20.6%), submandibular (15.9%), pterygomandibular (9.5%), submental (7.6%) and sublingual (2.8%) space. The number of the involved fascial space was one (75.2%), two (19.8%), or more than three (5.0%). In terms of the treatment duration, the hospitalization period of 6 to 10 days was the greatest in number (49.9%). All patients had uneventful recovery without major complication. There are statistically significant correlations between age and treatment period, and the involved space and treatment period, but no correlations between the variables of sex and treatment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.955-962
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• 2008

Multicast Strategy is one of the cost-saving methods in the large scale VOD environment. However, it does involve complicated problems to implement VCR-like interactions for user's convenience in the multicast streaming system under considering the limited-server and the network's bandwidth in the multicast-transmission system. Therefore, the proper solution of settling such a problem is necessary. Thus, this paper which revised P2Patching[l] proposes LGST(Level Group Streaming Technique) which supports the VCR's function through cooperation among peers with heterogeneous bandwidth under the environment of P2P. This strategy can reduce latency by improving the acceptance of server and using the bandwidth of network efficiently. And for evaluate the proposed scheme's performance, I simulated the performance of streaming delivery topology and streaming quality in comparison with P2Patching. In evaluation to service request refusal ratio and service quality according to bandwidth decrement, the result of simulation shows that proposed LGST improves about $11{\sim}18%$ of performance than P2Patching. In the test of latency recovery according to fault probability and influence of VCR function operation duration, it shows similar performance.

• Safety and Health at Work
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• v.5 no.3
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• pp.131-135
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• 2014

Background: Cassava and corn milling is a growing small-scale enterprise in Africa. We aimed to determine the incidence of hand-arm musculoskeletal complaints among vibration-exposed Congolese cassava and corn millers in the previous 12 months. Methods: A cross-sectional study was conducted, prior to a follow-up study, from March to May 2013 among cassava/corn millers in Lubumbashi, Democratic Republic of Congo, in which 365 millers age-matched to 365 civil workers anonymously answered a questionnaire. Results: Overall incidence of hand-arm musculoskeletal complaints was 25.8% in millers (vs. 5.2% in civil workers; p < 0.001). The risk of experiencing musculoskeletal symptoms was seven times higher in millers [vs. civil workers; odds ratio (OR) = 7.10; 95% confidence interval (CI): 4.03-12.50; p < 0.0001]; 2.4 times higher in smoking millers (vs. smoking civil office workers; OR = 2.36; 95% CI: 1.42-3.88; p < 0.001); 3.6 times higher in millers with longer daily exposure (> 8 hours; vs. those working ${\leq}8$ hours; OR = 3.56; 95% CI: 1.93-3.61; p = 0.026); and 7.4 times higher in young millers (vs. older millers, OR = 7.39; 95% CI: 1.29-75.52; p < 0.001). Smoking, number of cigarettes, and daily exposure duration were positively correlated with musculoskeletal complaints. Conclusion: This study revealed a relatively high incidence of musculoskeletal complaints among African cassava and corn millers. The use of anti-vibration protective equipment and the regulation of this hazardous occupation may reduce the burden of musculoskeletal disorders in millers.

• Plant Resources
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• v.6 no.2
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• pp.134-139
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• 2003

This study was conducted to investigate the relationships between yearly variations of meteorological elements and yearly variations of productivity in rice. In addition, correlation coefficients among yield and yield components were used to find out the relationships between meteorological elements and productivity. Yearly variation of the mean air temperature in May was large with coefficients of variation(C.V.) of 25.0%, but the variation of the duration of sunshine in May were relative small. No. of panicles per hill and 1,000 grains wt. of brown rice were great with C.V. of 21.1, 19.7%, respectively, brown rice yield show more or less C.V. of 5.5% and milled rice show still less variation. Correlation coefficients between temperatures in period of cultivation from May and yield were positive correlations. Correlation Coefficients between precipitation in period of cultivation from Sep. to Oct. and yield are positive correlations. Correlation coefficients amount the panicle length, no. of panicles, no. of spikelets, ratio of ripened grains, 1,000 grains wt. of brown rice, milled rice yield, brown rice yield and milled rice yield were positively significant at the level of 1 %, respectively.