• Atmosphere
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• v.21 no.4
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• pp.391-404
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• 2011

This study investigates the impact of cumulus parameterization scheme (CPS) with different horizontal grid sizes on the simulation of the local heavy rainfall case over the Korean Peninsula. The Weather Research and Forecasting (WRF)-based real-time forecast system of the Joint Center for High-impact Weather and Climate Research (JHWC) is used. Three CPSs are used for sensitivity experiments: the BMJ (Betts-Miller-Janjic), GD (Grell-Devenyi ensemble), and KF (Kain-Fritsch) CPSs. The heavy rainfall case selected in this study is characterized by low-level jet and low-level transport of warm and moist air. In 27-km simulations (DM1), simulated precipitation is overestimated in the experiment with BMJ scheme, and it is underestimated with GD scheme. The experiment with KF scheme shows well-developed precipitation cells in the southern and the central region of the Korean Peninsula, which are similar to the observations. All schemes show wet bias and cold bias in the lower troposphere. The simulated rainfall in 27-km horizontal resolution has influence on rainfall forecast in 9-km horizontal resolution, so the statements on 27-km horizontal resolution can be applied to 9-km horizontal resolution. In the sensitivity experiments of CPS for DM3 (3-km resolution), the experiment with BMJ scheme shows better heavy rainfall forecast than the other experiments. The experiments with CPS in 3-km horizontal resolution improve rainfall forecasts compared to the experiments without CPS, especially in rainfall distribution. The experiments with CPS show lower LCL(Lifted Condensation Level) than those without CPS at the maximum rainfall point, and weaker vertical velocity is simulated in the experiments with CPS compared to the experiments without CPS. It means that CPS suppresses convective instability and influences mainly convective rainfall. Consequently, heavy rainfall simulation with BMJ CPS is better than the other CPSs, and even in 3-km horizontal resolution, CPS should be applied to control convective instability. This conclusion can be generalized by conducting more experiments for a variety of cases over the Korean Peninsula.

• Journal of the Korean Society of Safety
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• v.30 no.5
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• pp.37-43
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• 2015

This study examined the effects of the minimum horizontal load on the structural behaviors and safety of system supports. The minimum horizontal load was frequently ignored in the design of system supports even though the level of that load was specified in the code and guide in Korea such as 'Standard Specification in Temporary Construction' and 'Guide to Installation of Shores for a Concrete Bridge'. To examine the effects of considering the minimum horizontal load, the finite element analysis were performed for various system supports. By varying installing parameters of system supports such as the vertical member spacing, the installation height, and the thickness of slab, the maximum combined stress ratios were estimated to investigate the structural safety of system supports. The results showed similar axial stress in vertical members but an increase in bending stress with a consideration of the horizontal load. The combines stress ratios are remarkably increased due to the consideration of the horizontal load. Consequently, the system supports, which were initially estimated to be safe when only the vertical loads were considered, were changed to be unsafe in most cases by the effects of the both the vertical and horizontal stresses. Therefore, the minimum horizontal load following the code and the guide is an essential load that could control the structural safety of system supports.

• Journal of the Korean Solar Energy Society
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• v.29 no.6
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• pp.102-109
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• 2009

The research on meteorological data in Korea has been carried out but without much consistency and has been limited to some areas only. Of relatively more importance has been the area in the utilization of the solar energy, however, the measurement of the global solar horizontal irradiation has been quite limited. In the current study, the actually measured value of the global solar horizontal irradiation from the meteorological data and the theoretically calculated value of the global solar horizontal irradiation from the cloud amount will be analyzed comparatively. The method of analysis will employ the standard meteorological data drafted by the Korean Solar Energy Society, the standard meteorological data from the presently used simulation program and the corresponding results have been compared with the calculated value of the global solar horizontal irradiation from the cloud amount. The results of comparing the values obtained from MBE(Mean Bias Error), RMSE(Root Mean Squares for Error), t-Statistic methods and those from each of the standard meteorological data show that the actually measured value of the meteorological data which have been converted into standard meteorological data with the help of the ISO TRY method give the monthly average value of the global solar horizontal irradiation. These values compared with the monthly average value from the IWEC from the Department of Energy of the USA show that the value of the global solar horizontal irradiation in the USA is quite similar. In the case of the values obtained from calculation from the cloud amount, the weather data provided by TRNSYS, except only slight difference, which means that the actually measured values of the global solar horizontal irradiation are significant. This goes to show that in the case of Korea, the value of the global solar horizontal irradiation provided by the Korea Meteorological Administration is will be deemed correct.

• Journal of the Korean Geotechnical Society
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• v.21 no.10
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• pp.41-48
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• 2005

The gravitational consolidation behavior of the dredged ground with horizontal drains is analyzed using a finite difference program developed for self-weight consolidation analysis with horizontal drains. The influence of area and direction of horizontal drains on the consolidation time and settlement is analyzed. Various field conditions such as the non-treated ground below horizontal drain installed ground, the accumulation of drained water at the end of horizontal drains, are also included in the analyses. It was found that a slight decrease of consolidation time is resulted in the twice increase of the sectional area of drains. Installing drains vertically can reduce the consolidation time more significantly than installing drains horizontally. The analyses showed quantitatively that the non-treated ground below the horizontal drain installed ground has much influence on long term consolidation settlement, and the accumulation of hydraulic head at the end of horizontal drains results in the increase of consolidation time and insufficient consolidation.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.15-22
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• 2008

Purpose: The attachment level is strongly associated with tooth loss and provides useful information on patterns of destruction of the periodontium. The presence of horizontal attachment loss would not be detected in clinical measurement. Therefore, the purpose of the present study was to estimate the patterns of periodontal destruction based on the attachment area and horizontal attachment loss in extracted teeth due to severe periodontitis. Materials and Methods: 307 teeth satisfied the criteria for assessment. An indirect method, based on digital images obtained from a digital camera and an image analysis program, was used to calculate the area of root surface and attachment loss and the extent of horizontal attachment loss. The data were analysed using SPSS. Results: No statistically significant differences among root surfaces were observed in anterior teeth on the loss of attachment area. However, in posterior teeth statistically significant differences in palatal surfaces of maxillary and mandibular premolar and molar surfaces compared with buccal surfaces were observed. Horizontal attachment loss was observed in 21.5% of the teeth examined. Frequency of horizontal attachment loss was highest in the maxillary first premolar (34.8%), followed by the maxillary second premolar (27.3%) and maxillary canine (25%). The mean length of horizontal attachment loss was 1.5mm. Conclusion: More meticulous examination will be needed of the palatal surfaces of maxillary and mandibular premolar and molar teeth. The percentage of teeth with horizontal attachment loss greater than 2.1 mm was 5.2%. Considering the length of curette blades, about 5.2% of teeth were not properly debrided. Therefore, Additional supportive therapy such as local drug delivery has to be considered in treatment of the first maxillary, second premolar and canine due to the high prevalence of horizontal attachment loss.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.228-233
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• 2008

In this paper, peak acceleration for horizontal vibration of buildings was estimated from the results of vibration tests using a shaking table. Human comfort of occupants is supposed to be satisfied according to the peak acceleration in NBCC and ISO6897, which have been used by Korean structural engineers. In the paper, we used a one-dimensional shaking table for horizontal vibration tests, which was mounted with a vibration house similar to a living space. Experimental results were obtained according to increasing accelerations in the range of 0.2Hz through 1.2Hz of frequency with five experimental groups, each of which was composed of eight persons. We obtained performance curves by dividing the distribution of perception from horizontal vibration tests into the ranges of 0${\sim}$25%, 26${\sim}$50%, 51${\sim}$75%, 76${\sim}$100% and then fitting the curves. Also we made a questionnaire based on human comfort criteria of foreign countries, and examined the feelings of subjects. From the results of horizontal vibration tests, it was found that acceleration of perception was low when frequency was high, and that visual and auditory senses affect the human perception for horizontal vibration of buildings.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.457-468
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• 1991

This investigation was designed to categorize Angle's class III malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class III malocclusion. The material selected for this study consisted in standard lateral cephalogram of one hundred and fifty five children, seventy four boys and eighty one girls, aged 6 through 15 years, having Angle's class III malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications,16 groups were classified FMN-A-B, SE-FMN-A according to the Ba-SE-Me, Ba-SE/R. 2. The sequences that have relatively high frequency are as follow; a) Horizontal Group l b) Horizontal Group 3 c) Horizontal Group 5 d) Horizontal Group 9 e) Horizontal Group 4 3. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/OP, PMV/MP. 4. The sequences that relatively high are as follows; a) Vertical Group 1 b) Vertical Group 3 c) Vertical Group 4 d) Vertical Group 8.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.48-56
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• 2011

Since the horizontal global radiation and hours of bright sunshine are a main factor for designing photovoltaic system, it is necessary to evaluate its characteristics all over the country. The work presented here are the investigation of horizontal global radiation and hours of bright sunshine in Korea. The data utilized in the investigation consist of horizontal global radiation and hours of bright sunshine collected for 28years(1982.12~2009.12) at measuring stations across the country. The analysis shows that the annual-average daily horizontal global radiation is3.61kWh/m2 and the annual-average daily hours of bright sunshineis 5.1 Hrs in Korea. We also constructed the contour map of hours of horizontal global radiation and hours of bright sunshine in Korea by interpolating actually measured data across the country.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.171-183
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• 1991

This investigation was designed to categorize Angle's class II malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class II malocclusion. The material selected for this study consisted in standard lateral cephalogram of two hundred and twenteen children, eighty eight boys and one hundred twenty four girls, aged 6 through 18 years, having Angle's class II malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications, 16 groups were classified according to FMN-A-B, SE-FMN-A, Ba-SE-Me, Ba-Se/Ra P. The sequences that have relatively high frequency are as follows: a) Horizontal Group 16 b) Horizontal Group 12 c) Horizontal Group 13 d) Horizontal Group 9 & 15 2. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/Occ. P. PMV/Mn. P. The sequences that relatively high frequency are as follows; a) Vertical Group A b) Vertical Group D c) Vertical Group C d) Vertical Group H 3. In vertical and horizontal skeletal classifications, the sequence that relatively high frequency are as follows; a) Group13-A b) Group16-A & 9-A c) Group12-A & 15-A d) Group16-C

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1120-1131
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• 2010

In this thesis the model tests were performed to the horizontal pull-out characteristics of a suction pile subjected to a pull in sands. For this model tests, soil conditions ($D_r$=65), three pile diameters (D=100, 150, 200mm) and five loading points (h/L=0, 0.25, 0.5, 0.75, 1) were changed. And the experimental results were also compared with those by the theoretical methods. The results by the experimental and theoretical analysis are as follows. The ultimate horizontal pull-out resistance by the model test increased as the loading point (h/L) moved downwards from the pile top, and the maximum value reached at the h/L=0.75. The theoretical ultimate horizontal pull-out resistance by Broms(1964) and Hong(1984) agreed well with that by the model test at h/L=0 and 0.25, but their results overestimated the experimental result at lower part of pile and the differences between the theoretical and experimental results were of great. While the horizontal loading applied at the upper part of pile, the pile moved to the horizontal direction with rotating clockwise. As the loading point moved downwards from the pile top, the rotating angle of pile was smaller.