• 소음진동
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• 제6권3호
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• pp.349-355
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• 1996

For a rail traffic noise, a typical source has a length of 200m - 400m so that the noise pollution areas have been located in the transition regions where the sound level drops between 3dB/dd and 6dB/dd. Therefore, in this region, parameters such as a horizontal distance from the track, the geometry of the ground surface, the environmental effect, and the boundary impedance condition play import roles, especially in our nation's situation. In this study, modelling techniques for the finite length of noise source have been investigated in order to evaluate the rail traffic noise level. Then. noise correction value .${\Delta}$SPL for various location in the track region is represented by the non-dimensionalized horizontal and parallel distance from the track. As an application, a high speed train is examined. Beas on the noise data measured for a Eurostar in France, the sound power value per unit length $H_1$is calcuated. It turns out that$H_1$is 109 dB. Overall sound power from the highspeed train to be serviced in our country is expected to 135 dBA.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.311-314
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• 2005

Supply chain optimization is one of the most important components in the optimization of a company's value chain. This paper considers the problem of designing the supply chain for a product that is represented as an assembly bill of material (BOM). In this problem we are required to identify the locations at which different components of the product arc are produced/assembled. The objective is to minimize the overall cost, which comprises production, inventory holding and transportation costs. We assume that production locations are known and that the inventory policy is a base stock policy. We first formulate the problem as a 0-1 nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables.

• 한국소음진동공학회논문집
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• 제17권7호
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• pp.605-610
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• 2007

In this paper a dynamic behavior(natural frequency) of a cracked cantilever beam subjected to follower force is presented. In addition, an analysis of the flutter and buckling instability of a cracked cantilever beam subjected to a follower compressive load is presented. Based on the Euler-Bernoulli beam theory, the equation of motion can be constructed by using the Lagrange's equation. The vibration analysis on such cracked beam is conducted to identify the critical follower force for flutter instability based on the variation of the first two resonant frequencies of the beam. Besides, the effect of the crack's intensity and location on the flutter follower force is studied. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments. The crack is assumed to be in the first mode of fracture and to be always opened during the vibrations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.2016-2034
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• 2011

Ubiquitous Healthcare (u-Healthcare) is the intelligent delivery of healthcare services to users anytime and anywhere. To provide robust healthcare services, recognition of patient daily life activities is required. Context information in combination with user real-time daily life activities can help in the provision of more personalized services, service suggestions, and changes in system behavior based on user profile for better healthcare services. In this paper, we focus on the intelligent manipulation of activities using the Context-aware Activity Manipulation Engine (CAME) core of the Human Activity Recognition Engine (HARE). The activities are recognized using video-based, wearable sensor-based, and location-based activity recognition engines. An ontology-based activity fusion with subject profile information for personalized system response is achieved. CAME receives real-time low level activities and infers higher level activities, situation analysis, personalized service suggestions, and makes appropriate decisions. A two-phase filtering technique is applied for intelligent processing of information (represented in ontology) and making appropriate decisions based on rules (incorporating expert knowledge). The experimental results for intelligent processing of activity information showed relatively better accuracy. Moreover, CAME is extended with activity filters and T-Box inference that resulted in better accuracy and response time in comparison to initial results of CAME.

• Steel and Composite Structures
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• 제11권2호
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• pp.149-168
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• 2011

This paper presents a computational study of column loss scenarios for typical multi-story steel buildings with perimeter moment frames and composite steel-concrete floors. Two prototype buildings (three-story and ten-story) were represented using three-dimensional nonlinear finite element models and explicit dynamic analysis was used to simulate instantaneous loss of a first-story column. Twelve individual column loss scenarios were investigated in the three-story building and four in the ten-story building. This study provides insight into: three-dimensional load redistribution patterns; demands on the steel deck, concrete slab, connections and members; and the impact of framing configuration, building height and column loss location. In the dynamic simulations, demands were least severe for perimeter columns within a moment frame, but the structures also exhibited significant load redistribution for interior column loss scenarios that had no moment connectivity. Composite action was observed to be an important load redistribution mechanism following column loss and the concrete slab and steel deck were subjected to high localized stresses as a result of the composite action. In general, the steel buildings that were evaluated in this study demonstrated appreciable robustness.

• 대한공간정보학회지
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• 제10권2호
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• pp.29-37
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• 2002

도로상에서 발생되는 교통사고의 많은 부분이 도로의 선형불량에 기인된다. 이러한 도로의 개량설계를 위하여서는 도로의 선형을 정확히 분석할 필요가 있으며, 도로의 설계도와 주요진의 좌표가 필요하게 된다. 따라서, 본 연구에서는 현재 많이 연구되고 있는 인공위성 중 RTK GPS/GLONASS의 조합에 의하여 획득된 자료를 기존 설계도의 제원을 근거로 하여 위치정밀도를 비교하였다. 연구 결과 관측된 도로선형 자료는 5cm 범위 내에 포함되었으며, 이렇게 재현된 도로의 선형을 평가함으로써 인공위성을 이용한 도로의 선형정보체계를 보다 효율적이고 실용적으로 사용하기 위한 한 접근방법을 제시하고자 한다.

• 대한공간정보학회지
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• 제4권1호
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• pp.83-91
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• 1996

도시의 발달로 도시 외곽 도로의 산지를 통과하는 도로의 건설이 요구되지만 그 계획을 실행함에 있어서 많은 문제점들이 있다. 이것은 도로계획시 노선의 위치를 결정하는데 있어서 토공작업을 예측하고, 경관을 식별하여, 식생 및 토지이용 관계를 해석하므로 계획과 실행에서 도움을 주는 것이다. 본 연구에서는 36km에 달하는 광주 외곽을 순회하는 도시고속순환도로 중 제 1구간인 동광주 I.C 에서 소태 I.C까지의 노선의 일부 5Km를 연구 대상으로 결정하여 G.I.S에 의해 해석하였다. 그리고 설계도의 계획고와 같은 자료를 이용하여 조망 위치에 따라 달라지는 경관을 구간별로 도시하였으며, 광주의 명소인 무등산 주위를 순환하는 본 연구지를 G.I.S기법을 이용하여 지형경관을 해석하여 결론을 얻었다

• 천문학회보
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• 제42권1호
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• pp.41.1-41.1
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• 2017

It is well known that there are good relations of coronal hole (CH) parameters such as the size, location, and magnetic field strength to the solar wind conditions and the geomagnetic storms. Especially in the minimum phase of solar cycle, CHs in mid- or low-latitude are one of major drivers for geomagnetic storms, since they form corotating interaction regions (CIRs). By adopting the method of Vrsnak et al. (2007), the Space Weather Research Center (SWRC) in Korea Astronomy and Space Science Institute (KASI) has done daily forecast of solar wind speed and Dst index from 2010. Through years of experience, we realize that the geomagnetic storms caused by CHs have different characteristics from those by CMEs. Thus, we statistically analyze the characteristics and causality of the geomagnetic storms by the CHs rather than the CMEs with dataset obtained during the solar activity was very low. For this, we examine the CH properties, solar wind parameters as well as geomagnetic storm indices. As the first result, we show the different trends of the solar wind parameters and geomagnetic indices depending on the degree of solar activity represented by CH (quiet) or sunspot number (SSN) in the active region (active) and then we evaluate our forecasts using CH information and suggest several ideas to improve forecasting capability.

• 전자공학회논문지A
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• 제28A권1호
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• pp.23-29
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• 1991

In order to improve the radiation characteristics of the microstrip antenna, microstrip array antenna consisting of one center patch fed by a coaxial probe and several patches directly coupled to the E-plane by microstrip line is analyzed. The equivalent circuit of the array antenna is represented by the conventional transmission line and the various parameters, such as the mdicrostrip line length, the patch length and the feed point location are calculated to improve the radiation pattern for 5-patch array antenna which has the equal patch width. The 5-patch array antenna with the radiation pattern which has low sidelobe level and narrow beam width is fabricated and then the measured results are compared with the computed values and the results of the single patch microstrip antenna too.

• 한국수산과학회지
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• 제50권6호
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• pp.829-836
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• 2017

This study investigated the species composition and abundance of floating fish eggs to determine the timing and location of spawning of fish inhabiting the coastal waters of Sagye, Jejudo Island. Eggs were collected with a Bongo net bimonthly from May 2009 to February 2010. Identifications were based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Eggs were determined to belong to 43 distinct taxa, 35 of which were identified to the species level. The assemblage spanned eight orders, 23 families, and 32 genera. The number of taxa collected varied from month to month, with 14 taxa (12 species) found in June 2009, 11 taxa (10 species) in October 2009, 10 taxa (nine species) each in August 2009 and February 2010, eight taxa (six species) in April 2009, and five taxa (four species) in December 2009. Five abundant species (Branchiostegus japonicus, Engraulis japonicus, Pseudolabrus sieboldi, Goniistius zonatus, and Halichoeres tenuispinis) together represented 52.8% of the total number of eggs collected during the study.