• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.1-12
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• 2018

This study presents the seismic response characteristics of domestic cable-supported bridges due to 3 earthquakes with magnitudes of 5.1, 5.8, and 4.5 in Richter scale, which occurred around Gyeongju region in 2016. The seismic acceleration response signals, recorded by the seismic acceleration sensors at the free field near bridge and designated positions on bridge, are utilized to characterize the seismic responses of structural elements of cable-supported bridges. The dynamic behaviors of bridges are presented through Fourier transform of acceleration time history. Using the peak accelerations normalized by those at the free fields, amplification effects on the tops of the pylons are analyzed comparatively bridge by bridge. Using aforementioned analyses, the necessity of development on the creteria of alert levels is discussed for the earthquake disaster response of cable-supported bridges.

• The korean journal of orthodontics
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• v.6 no.1
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• pp.55-63
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• 1976

This study was undertaken to establish the roentgenocephalometric standards of the Korean children in Hellman dental age III C. The subjects consisted of 33 males and 33 females with the normal occlusion and acceptable profile. The lateral cephalometric films were taken with the teeth in centric occlusion, the soft tissue outline of the nose, lips, and chin was made visible by the low-speed films, 70Kvp, 100Mas. Their linear and angular measurements were performed by Jarabak's methods. The following results were obtained; 1) The author made the tables of standard deviation from the measured values. 2) Each linear measurement of the skull was greater in males than in females. 3) The maxillary basal bones were more protrusive in Korean children than in Caucasian. 4) The degree of the facial convexity was larger in Korean children than in Caucasian. 5) The labial inclination of the upper & lower incisors was greater in Korean children than in Caucasian. The labial inclination of the upper incisor was greater in females, but the labial inclination of the lower incisor was greater in males.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.8
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• pp.637-644
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• 2003

Airborne noise is one of the considerable environmental factors for navy ship personnel who should accomplish their tasks in restricted ship spaces against adverse health effect of noise. However, it is difficult to find studies on actual condition of airborne noise for navy ships. In this study, we measured airborne noise levels at 379 compartments of 33 Korean navy ships. Using the measured data, we presented mean values and their standard deviations of measured noise levels with factors of ship type, compartment category, and operation mode. Additionally, we evaluated the mean value and cumulative probability of airborne noise levels of compartments with those of the US navy ships. These results can be rationally used in making the proper airborne noise criteria of the navy ship for the future.

• Proceedings of the KSEE Conference
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• 2006.10a
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• pp.55-66
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• 2006

일반적으로 현장에서의 발파공법의 적용은 보안물건과 발파지점의 거리로 구분하여 설계한 종례의 방법에서 탈피하여 건설교통부에서 보안시설건물의 거리${\sim}$지발당장약량을 기초로 한 6가지의 타입으로 표준화한 방법을 제시하였다. 이는 시험발파를 통하여 발파공해 허용 기준치를 확보하고 회귀분석을 통한 발파영향권을 분석한 후 이격거리별 발파패턴 및 발파공법을 선정 및 설계를 기본으로 하는 것이며 이번 00대학교 민석도서관 건립공사에서 적용하여 타당성을 검토하여 실제 설계 시 적용을 하였으며 6 가지 타입의 기초적인 모델링을 기본으로 하여 시공설계 및 계측결과를 분석하였다.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.359-364
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• 2006

경부고속철도 교량은 대부분 콘크리트교량으로 2@40m와 3@25m의 박스거더교량의 대표적인 형식이다. 일부구간에서 단경간 또는 2경간 연속 50 m 2주형을 갖는 강합성교량이 건설되었다. 연행하는 차륜이 반복해서 통과하는 철도교량은 주기적인 동적하중에 의하여 공진이 발생할 수 있으며, 특히 고속전철이 통과하는 교량은 저속차량이 통과하는 일반철도보다 공진의 발생가능성이 클 뿐 아니라 고속으로 주행하는 열차의 주행안정성 확보를 위해서 엄격한 제한조건을 만족시켜야 하는 엄밀한 동적설계 조건을 갖게 된다. 그러한 조건 중에서 가속도의 제한 규정은 UIC에서 제안된 기준치로서 도상을 갖는 경우에 0.35g이하를 만족시키도록 요구하고 있다. 현재 KTX가 주행하는 교량에서는 일부구간 및 시점에서 규정치를 초과하는 값을 보이고 있는 것으로 계측되었으며, 그 원인 및 대책마련을 위한 연구를 수행하고 있다. 본 연구에서는 그러한 과도한 가속도의 원인 규명을 위한 각종 매개변수 연구와 그 해결책 마련을 위한 연구를 수행하였으며, 경제적이면서도 효과적인 진동저감 방안을 제시하고 있다.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.322-327
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• 2006

Banwol bridge with steel plate girder and Pyongtaek bridge with PSC bos girder have been operated maintenance measuring system by the Seoul-Chonan of Kyongbu express railway. By analyzing the theoretical and experimental values of design load for these two bridge, the establishment of reference maintenance for measuring items was deduced from research. Two materials, steel and concrete plates, were considered as the upper structure. Actual measurement data for the behavior under speed, structural analysis results, and the presented references were analyzed and used to set up the reference establishment. The measuring items are stress(strain), displacement, dynamic acceleration, expansion movement, and dynamic frequency. The maintenance reference was established by comparing analytical and measuring values of the five items with respect to structural state class.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.295-303
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• 2002

This study was performed to establish the cephalometric standards in Downs analysis and to compare them with other races. The lateral cephalograms of 88 Korean children (47 boys, 41 girls) with normal occlusion and acceptable profile between 7 and 11 years of age were taken and Downs analysis was done. Results were as follows: 1. Norms of Korean boys, girls and both sexes at 7, 9, 11 years of age by Downs analysis were established. 2. There were no statistically significant differences between boys and girls about ten measurements in each group, but significant differences in the occlusal plane angle, lower 1 to occlusal plane angle, interincisal angle, upper 1 to APog plane among 3 groups(p<0.05)(p<0.01). 3. Facial angle, AB plane angle, Y-axis, lower 1 to occlusal plane angle and lower 1 to mandibular plane angle showed increasing tendency whereas angle of convexity, mandibular plane angle, occlusal plane angle and interincisal angle did decreasing tendency according to aging. 4. In comparison among races, measurements in Korean children were generally larger than those of Caucasian and Greek except for small interincisal angle, but Korean were similar to Japanese, Chinese, Israeli, Negro about all measurements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4046-4053
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• 2011

In order to increase the accuracy and efficiency in measuring obesity conducted outside the hospitals, we examined not only the Body Mass Index and cutoff values of waist circumference of 3,281 adults but also considered their gender, age and various body characteristics. This study included 1,505 males (45.9%) and 1,776 females (54.1%) who visited the comprehensive health checkup center. The average body fat content of male participants was 22.2%, and their Body Mass Index was 24.4kg/$m^2$. The average Body Mass Index of female participants was 22.9kg/$m^2$. The average of waist circumference of male subjects was 86.2cm while that of female subjects was 76.9cm. The conventional method to measure obesity using BMI and WC only does not reflect the actual body fat which may change according to one's gender and age. Therefore, for those who visit individual's place to measure obesity outside the hospitals only based on BMI and WC, we need a new standard to measure obesity more accurately.

• The korean journal of orthodontics
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• v.33 no.5 s.100
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• pp.323-337
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• 2003

This study was performed to establish Korean soft tissue cephalometric norms, to compare the norms between sexes and between races, and then to suggest a guideline to execute orthodontic diagnosis and treatment planning for dentofacial deformities in Korean. Young Korean adults were selected. They were 27 males $(23.8{\pm}2.6-year-old)$ and 20 females $(22.5{\pm}1.7-year-old)$ who had harmonious facial balance. After taking lateral cephalograms under the natural head position which is widely known as a highly reliable and reproducible reference position, films were traced and analysing factors were measured as introduced by Arnett et at. Comparisons were done between male and female groups and between Korean and Caucasian groups using unpaired t-test. From the results it was concluded that Korean male had generally thicker lower facial soft tissue and smaller nasolabial angle, longer facial height, deeper facial depth, and more protrusive lower face than Korean female. From the comparison with Caucasian norms adopted from the research of Arnett et al., both Korean male and female showed longer facial lengths generally except less exposed maxillary incisor, and shorter facial depth than Caucasian counterparts. Also, both races showed similar horizontal position of maxillary structures from TVL (true vertical line), but there were more significant anteroposterior differences of marilla-mandible in Korean groups. These results mean Korean had relatively more retruded mandibular structures from the reference line, TVL. Individuals who had harmonious facial balance showed similar facial angle, more or less 170 degree, regardless of sexes or races.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.79-88
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• 2022

Cable-supported bridges, as important large infrastructures, require a long-term and systematic maintenance strategy. In particular, various methods have been proposed to secure safety for the bridges, such as installing various types of sensor on members in the bridges, and setting management thresholds. It is evidently necessary to propose a strategic plan to efficiently manage increasing number of cable-supported bridges and data collected from a number of sensors. This study aims to develop an analysis tool that can automatically remove abnormal signals and calculate statistical results for the purpose of efficiently analyzing a wide range of data collected from a long span bridge measurement system. To develop the tool, basic information such as the types and quantity of sensors installed in long span bridges and signal characteristics of the collected data were analyzed. Thereafter, the Humpel filtering method was used to determine the presence or absence of an abnormality in the signal and then filtered. The statistical results with filtered data were shown. Finally, one cable-stayed bridge and one suspension bridge currently in use were chosen as the target bridges to verify the performance of the developed tool. Signal processing and statistical analysis with the tool were performed. The results are similar to the results reported in the existing work.