• Journal of agriculture & life science
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• v.45 no.2
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• pp.51-59
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• 2011

This study was conducted to analysis the growth characteristics and the diameter at breast height (10 cm) reached ages in natural stand and platation for the optimal planting density and planting timing of Acer mono for. rubripes. There was high correlation between the DBH and crown diameter (E-W: r=0.82, S-N: r=0.76) in natural stand, and between the DBH and crown diameter (E-W: r=0.76, S-N: r=0.90) in plantation. In natural stand, average reached age on DBH 10 cm was $21.1{\pm}7.0$, and was $9.2{\pm}1.3$ in plantation. Therefore, the collectable timing of sap in artificial planting short approximately 2.3 times over the natural regeneration.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.170-173
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• 2012

화재상황에서 가장 우선시 되는 것은 신속하고 안전한 인명의 구조이므로 구조대의 역할은 매우 중요하여 이와 관련된 기준을 법에서 별도로 지정하고 있다. 그러나 현재 구조대의 편성과 배치는 시도별 상황이나 재정여건 등에 따라 상이한 편으로, 구조대 접근에 있어 취약지가 발생하는 것도 사실이다. 이에 본 연구에서는 실제 도로 데이터와 응급구조 차량의 특성을 고려한 접근성 분석을 통해 대구광역시의 구조대 도달 취약지를 도출하고 이에 따라 개선방안을 제시하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3594-3602
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• 2011

The purpose of this study is complementing existing flood-reaching timetable by theoretically determined numerical model and suggesting techniques for calculating the exact arrival time of flood. For this, according to the discharge of Namhan River, arrival time measurements, using u-IT technology applied sensor buoys, were performed. Based on the results of measurements, this study proposed complementary relation of average reach time by the discharged water considering tributary inflow, which was not considered established expression. With this study, u-IT based actual technology that is complementing the existing flood forcasting-warning data was developed. Applying this technology to the average reach time calculation by the discharged water, it is expected to reduce flood-oriented damage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1269-1275
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• 2002

This paper presents a new method for removing reaching phase in variable structure control systems using Bell type switching function. By proposed method, during the entire control process reaching phase is removed. For effective speed control of trapezoidal type brushless DC motor, a time varying switching function based speed controller is developed as illustration.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.5
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• pp.21-28
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• 1998

This study develops a variable structure controller using the time-varying nonlinear sliding surface instead of the fixed sliding surface, which has been the robustness against parameter variations and extraneous disturbance during the reaching phase. By appling TS fuzzy algorithm to the regulation of the rionlinear sliding surface, the reaching time of the system trajectory is faster than the fixed method. This proposed scheme has better performance than the conventional method in reaching time, parameter variation and extraneous disturbance. To demonstrate its performance, the proposed control algorithm is applied to a rotational inverted pendulum.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.165-170
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• 2011

The Pfair scheduling algorithm, which is an optimal algorithm in the hard real-time multiprocessor environments, is based on the fixed quantum size. Recently, several methods that can determine the optimal quantum dynamically are developed in the mode change environments. These methods are based on the reach function and in many cases, we have to do the sequential search to find the optimal quantum. In this paper, we propose a new scheduling method, based on the improved reach function, that can determine the optimal quantum more quickly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.835-840
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• 2010

This study develops a variable structure controller using nonlinear surface instead of the fixed, which has been the robustness against parameter variations and extraneous disturbance during the reaching phase. reaching time of the system trajectory is faster than the fixed method. This proposed scheme has better performance than the conventional method in reaching time, parameter variation and extraneous disturbance. The effectiveness of the proposed control scheme is verified by simulation results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.51-56
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• 2014

TETRA(TErrestrial Trunked RAdio) provide specialized disaster radio communication services as a standard European for digital TRS(Trunked Radio System). Especially, DMO(Direct Mode Operation) feature is used effectively in the radio shadow areas which base station does not propagate radio signal because it can communicate directly with terminal to terminal without base station's relay function. However, to effectively used DMO feature, radio coverage prediction information should be provided to users. Therefore in this paper, we were calculated link budget of TETRA DMO terminals which were distributing and operating in the country and then predicted reaching distance about radio propagation to be applied with path loss model.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.25-40
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• 2015

Korean tourist areas are designated/managed in accordance with the Tourism Promotion Act. Since Taejongdae was designated as a tourist area in 1969, a total of 230 tourist areas have been designated/built/operated. It has been 46 years since the first tourist area was designated. According to the Tourism Area Life Cycle by Butler, it is estimated that the flow of the life cycle will be reflected in ups and downs over time. Thus, this study aimed to provide basic data for suggesting the direction of changes and development of the future tourist areas after analyzing the life cycle stage of domestic tourist areas, by applying the Tourism Area Life Cycle by Butler. The research method was based on the tourist areas by year, the number of visitors, and data of the target to derive the change transition curve, obtained by dividing the life cycle stages of the tourist areas based on the visitor rate of change. In the analysis results, more than 1/3 of domestic tourist areas are reaching the stagnation/decline stage, and tourist areas such as hot springs and seaside/beach resources show a particularly high ratio of stagnation/decline. The tourist areas that already have reached the stagnation/decline stage will need to analyze the causes for the decline, seek for resolution measures, and introduce new innovative elements. Even though the results of this study are not sufficient to be used as an absolute standard to decide the life cycle stage of domestic tourist areas, it is considered to be adequate for phenomenologically understanding the life cycle stage of Korean tourist areas. Based on this study, the causes for the stagnation/decline of tourist areas can be revealed while it can be also used as basic research to establish revitalization measures for tourist areas by introducing new innovation.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.1-7
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• 2023

The purpose of this study is an experimental research to investigate the effectiveness of debris flow reduction structures when a debris flow disaster occurs on a steep slope. The control structure for debris flow took the form of baffle, and the soil deposition area and soil runout distance due to debris flow from the downstream were investigated according to the installation number of baffle and each specification. As the slope of the channel became steeper, the sediment deposition area and runout distance increased, and as the sediment volume concentration decreased, the sediment deposition area and runout distance increased. When the sediment concentration was low, differences appeared depending on the slope of the channel because the debris flow had a high liquid content. Overall, the larger the sediment volume concentration, the greater the decrease in sediment deposition area and soil runout distance. As the number of baffles increases, the soil deposition area and runout decrease, showing that the baffles have the ability to control debris flows. The results of this research will provide good information when installing attenuation or control structures when sediment disasters occur in steep slopes.