• The Journal of Korean Academy of Prosthodontics
• /
• v.53 no.4
• /
• pp.359-365
• /
• 2015

Long-term use of ill-fitting dentures may cause irregular movements of the mandible. In such cases, satisfactory outcomes both in terms of function and esthetics could be achieved by accurate registration of mandibular movement and centric relation when fabricating new dentures. In this case, treatment dentures with flat occlusal tables were used to register centric relation and mandibular movements of a patient with erratic mandibular movements.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.12
• /
• pp.2655-2663
• /
• 2011

Several algorithms have been developed to detect AF which rely either on the form of P waves or the based on the time frequency domain analysis of RR variability. However, locating the P wave fiducial point is very difficult because of the low amplitude of the P wave and the corruption by noise. Also, the time frequency domain analysis of RR variability has disadvantage to get the details of irregular RR interval rhythm. In this study, we describe an atrial fibrillation detection algorithm through non-linear analysis of irregular RR interval rhythm based on the variability, randomness and complexity. We employ a new statistical techniques root mean squares of successive differences(RMSSD), turning points ratio(TPR) and sample entropy(SpEn). The detection algorithm was tested using the optimal threshold on two databases, namely the MIT-BIH Atrial Fibrillation Database and the Arrhythmia Database. We have achieved a high sensitivity(Se:94.5%), specificity(Sp:96.2%) and Se(89.8%), Sp(89.62%) respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.6
• /
• pp.705-712
• /
• 2001

It is of great importance to represent the directional ocean waves in a laboratory basin for hydraulic model tests. The directional ocean waves can be expressed as a linear superposition of a large number of component waves with different frequencies and propagating directions. The aim of the study is to check the wave generating characteristics by serpent-type wave generating system in PKNU (Pukyong National University) which is composed of 10 piston-type wave generators. In the experiment, spatial variation of irregular wave heights and propagating angles are measured in the multi-directional wave maker basin. Target wave directional spectrum is reproduced in the area of multi-directional wave maker basin. The directional spreading of the generated waves varied spacially in the basin. They differed from target spectrum as the measurement point becomes far from the center line normal to the generator face, The effective generation area where that target can be reproduced is limited to the triangular area attached the generator face. According to the results, it is emphasized that the effective experiment area in the basin considered wave generator characteristics should be determined in consideration of experimental conditions including structural shapes, water depth, wave directionality etc.

• 한국지구과학회:학술대회논문집
• /
• 2010.04a
• /
• pp.114-114
• /
• 2010

중성자별을 포함하는 이중성인 EXO 0331+350을 가시광선 및 자외선으로 관측하였다. EXO 0331+350은 전형적인 Be/X-선 이중성인 것처럼 보이지만 특이하게도 공전 주기상의 근일점 마다 매우 밝아지는 다른 Be/X-선 이중성들과는 확연히 다르게 밝아지는 시기가 매우 불규칙하다. 따라서 그 물리적인 기작을 연구하기 위해서는 오랜 기간의 모니터링이 필수적이다.

• Journal of Nutrition and Health
• /
• v.52 no.6
• /
• pp.604-617
• /
• 2019

Purpose: To investigate the effect of eating behavior on nutritional status according to temperament type. Methods: One thousand one hundred three preschool children aged 2 to 6 years in Gyeongsan, Gyeongsangbuk-do from April to June 2018 were surveyed about their eating behavior and nutritional status using DBT (Dietary Behavior Test) and NQ (Nutrition Quotient) which are proven tests. The dietary behaviors of the children were classified into four categories: approach avoidance, sensory sensitivity, hyperactivity, and irregularity. NQ scores were divided into five categories: balance, diversity, moderation, regularity, and practice. Results: The mean of the children's age was 3.42 ± 1.4 (596 boys and 507 girls). The percentage distribution of the NQ grade was as follows: 5.5% (highest), 12.5% (high), 47.1% (medium), 22.2% (low), and 12.6% (lowest). The risk group of approach avoidance and sensory sensitivity had significantly (p < 0.001) lower scores than the normal group in balance factor (51.9 ± 12.0 vs. 57.8 ± 15.9 in approach avoidance type, 52.6 ± 17.6 vs. 57.7 ± 15.9 in sensory sensitivity type) and diversity factor (32.5 ± 24.4 vs. 50.1 ± 22.4 in approach avoidance type, and 32.5 ± 24.0 vs. 50.7 ± 22.2 in sensory sensitivity type). The scores of the hyperactivity risk group were significantly lower in moderation factor (78.2 ± 12.1 vs. 81.2 ± 11.9), and those of the irregular risk group were significantly lower in variety (35.9 ± 24.5 vs. 48.8 ± 23.2), regularity (57.6 ± 37.1 vs. 66.1 ± 17.6), and practice (57.1 ± 19.4 vs. 65.1 ± 22.5) factors than the normal group (p < 0.001). Especially, the risk group of approach avoidance and sensitivity type had significantly (p < 0.001) lower intakes of whole grain, fruit, bean and bean products, vegetables, and Kimchi. Conclusion: This present study suggested that the eating behavior based on temperament of demanding preschool children affected food choice resulting in food consumption diversity of children. Therefore, it is important to provide customized nutrition education programs based on temperament type.

• Journal of Korea Water Resources Association
• /
• v.53 no.4
• /
• pp.303-312
• /
• 2020

An underground deep tunnel system is a facility in form of a reverse siphon for an under flood defense structure. In this study, the 'Shinwol rainwater storage and drainage system', which is under construction for the first time in South Korea, in order to confirm the effects of undular bore and pressurized air on the hydraulic stability of the facility in various flood scenarios a hydraulic model experiment was performed. As a result of this study, it was analyzed that the undular bore generated downstream pushed the pressurized air collected in the facility while moving upstream, and the pressure inside the pipe increased at this time. It was analyzed that the pressure during the passage of the undular bore was greater than the sum of the static pressure and dynamic pressure at the time and overflow occurred when the cross-sectional size of the pressurized air was more than 40% of the cross sectional area of the tunnel. It is determined that this is correlated with the volume of pressurized air collected in the facility, and it is determined that it is necessary to study the relationship between velocity of undular bore and the volume of pressurized air in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.30 no.2
• /
• pp.39-50
• /
• 2018

In this study, the nonlinear interaction of irregular waves with wave breaking and currents around permeable submerged breakwater was investigated with the aid of olaFlow model which is open source CFD software published under the GPL license. The irregular wave performance of olaFlow applied in this study was verified by comparing and evaluating the target frequency spectrum and the generated frequency spectrum for applicability to irregular waves. Based on the applicability of this numerical model to irregular wave fields, in the coexistence fields of irregular waves and currents, the characteristics of wave height, frequency spectrum, breaking waves, averaged velocity and turbulent kinetic energy around porous submerged breakwater with the respect to the beach type and current direction versus wave propagation were carefully investigated. The numerical results revealed that the shape of wave breaking on the crown of the submerged breakwater and the formation of the mean flow velocity around the structure depend greatly on the current directions and the type of the beach. In addition, it was found that the wave height fluctuation due to the current direction with respect to the wave propagation is closely related to the turbulent kinetic energy.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.27 no.4
• /
• pp.238-245
• /
• 2015

Recently, Choi et al.(2015) showed that a numerical simulation of the SandyDuck experiment under a directional random wave environment agreed well with the experimental data including the wave height distribution of the random waves, the well-developed longshore current and its energetic fluctuation. Based on the Boussinesq modeling, this study investigates the effect of the alongshore variations, which are induced by not only the field topography but also the phase interaction of multidirectional random waves in the surf zone wave field, on the rip currents. As a result, transient rip currents as well as topographical rip currents cause the complicated surfzone circulation and mixing process due to their interactions in a multi-directional random wave condition while the topographical rip currents are dominant in a monochromatic wave condition.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.208-213
• /
• 2009

본 논문에서는 Tree-ring width 지표자료, 태양흑점수, 남방진동지수(SOI) 및 지구온도 아노말리 자료와의 비교를 통하여 서울지점 측우기 강우량 자료의 정확도를 가늠해 보았다. 그리고 한반도 인근지역의 Tree-ring width 지표자료와의 비교를 통하여 과거 동북아시아 기후변화 상관성과 변화특성을 파악해 보았다. 분석 결과 측우기 강우량 자료는 다른 비교분석 대상 자료들과 경향성과 변화심도가 매우 잘 일치하고 있어 상당한 신뢰성을 가지고 있음이 확인되었다. 그리고 한반도 주변 6개 지점의 Tree-ring width 지표자료와의 비교분석결과, 장기적으로 동북아시아 기후는 시공간적으로 밀접한 상관을 가지고 변화하고 있으며 그 변화에는 장주기적인 재현성이 존재한다는 점을 알 수 있었다. 그러나 1960년 이후의 기후변화 특성은 통계적인 거동특성이나 변화폭이 과거의 재현사상의 한계를 넘지는 않으나 과거와는 다른 경향성과 불규칙성을 보여주고 있으며 재현주기도 짧아지고 있어 과거와는 다르게 나타나는 것으로 분석되었다. 과거자료에 근거한 본 연구의 결과는 동북아시아 기후변화 장기 예측에 있어 유용하게 이용될 수 있을 것으로 판단된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.6 no.1
• /
• pp.25-34
• /
• 1988

Digital Terrain Model is composed of two basic elements, namely, sampling and interpolation. They represent the procurement of data and the geometric reconstruction of terrain relief respectively. For evaluation DTM data, following two paremeters appear to be the most important factor, that is, the accuracy and efficiency and, in particular, the break point information significantly affect to the accuracy of DTM data. The main objective of this study is to improve the accuracy and efficiency of DTM by applying Progressive Sampling with distinct morphologic information. In this study, the total of 240 individual numerical tests has been implemented and the appropriate computer program is also developed for the test. The result of investigation shows that the Progressive Sampling with break point information improves the accuracy of DTM by 30 percent approximately.