• 한국초등수학교육학회지
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• 제20권3호
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• pp.371-391
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• 2016

장제법은 1990년대부터 시작된 미국의 제 2차 수학전쟁의 주요 쟁점중의 하나였다. 이 논문에서는 이에 관하여 구체적으로 고찰하고 그를 바탕으로 우리나라 초등수학교육에서 장제법 지도 현황을 조사하였다. 첫째, 장제법은 나눗셈의 답을 구하는 기계적 알고리즘이 아니라 초등수학의 핵심 개념을 구현하고 있으며 중등수학과의 연결고리 역할을 하는 중요한 원리이다. 둘째, 우리나라 교육과정에서 장제법이라는 명칭을 사용하고 구체적인 지도 지침을 제시해야 한다. 셋째, 장제법의 이해를 돕기 위하여 부분몫 방법 같은 다른 나눗셈 알고리즘을 보조적으로 활용할 필요가 있다.

• Journal of Ecology and Environment
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• 제33권4호
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• pp.307-315
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• 2010

Males of the field cricket Teleogryllus emma produce calling songs that are attractive to receptive females. The calling songs of T. emma consist of two components, the long chirp that is composed of up to 12 single pulses, followed by a variable number of short chirps. Based on the analysis of coefficient of variation (CV), temporal characters of the long chirp were less variable than those of the short chirps in male calling songs. To test for phonotactic selectivity of females, we conducted a single-stimulus playback experiment in which five stimuli (standard, long chirp only, long chirp augmented, short chirps only, and short chirps augmented) were used. The standard stimulus included both long and short chirps whose characteristics were derived from the calling songs of field populations. Results of the playback experiment showed that female crickets oriented more frequently toward the stimuli that included the long chirp (standard, long chirp only, and long chirp augmented stimuli) than toward the stimuli lacking the long chirp (short chirps only and short chirps augmented stimuli), indicating that the long chirp in the calling songs was required to elicit positive phonotaxis in the female crickets. The result of CV analysis of the male calling songs and the findings of the female phonotaxis experiment suggested that the long chirp of calling songs may play a role in species recognition in T. emma.

• 한국안전학회지
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• 제19권2호
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• pp.119-124
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• 2004

The effect of soil-structure interaction becomes important in the design of civil structures such as long-span bridges, which are constructed in the site composed of soft soil. Many methodologies have been developed to account for the proper consideration of soil-structure interaction effect. However, it is difficult to estimate soil-structure interaction effect accurately becaused of many uncertainties. This paper presents the results of study on soil-structure interaction and dynamic response of a long-span bridge designed in the site composed of soft soil. The effect of the soft soil was evaluated by the use of computer program SASSI and a long-span bridge structure was modeled by finite elements. Dynamic response characteristics of a long-span bridge considering soil-structure interaction wereinvestigated.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.251-258
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• 2005

In this study, a new concept for simulating a long-term mechanical degradation mechanism of shotcrete in tunnels has been proposed. In fact, it is known that the degradation takes place mainly by internal cracks and reduced stiffness, which results mainly from volume expansion of shotcrete and corrosion of cement materials, respectively. This degradation mechanism of shotcrete in tunnels appears similar to those of the most kinds of chemical reactions in tunnels. Therefore, the mechanical degradation induced by a kinds of chemical reaction was generalized and mathematically formulated in the framework of thermodynamics. The numerical model was implemented to a 3D finite element code, which can be used to simulate behaviour of shotcrete structures undergoing external forces as well as chemical degradation in time. A number of illustrative examples were given to show the feasibility of the model in tunnel designs with consideration of long-term degradation effect of shotcrete quantitatively for increase of long-term safety of tunnels.

• Journal of Ecology and Environment
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• 제31권1호
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• pp.31-36
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• 2008

Larvae of the long-tailed clawed salamander, Onychodactylus fischeri, have a relatively long larval period, spending a year or more within the stream where they hatch; therefore, a well-established larval population could be critical for the conservation of adult populations. To study the population dynamics of long-tailed clawed salamander larvae, we surveyed a field population once or twice a month from September, 2005 to June, 2006, and determined the age of larval clawed salamanders collected from three different populations in October, 2004 using skeletochronology. The age of long-tailed clawed salamander larvae ranged from 0 to 3 years. New recruitment of larvae in the population primarily occurred in November, 2005, and mid-March, 2006. Larvae with a snout-vent length of more than 30 mm disappeared from the streams in September, 2005, suggesting that two to three year-old clawed salamander larvae metamorphosed during this period.

• 비파괴검사학회지
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• 제21권4호
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• pp.383-390
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• 2001

Long-range guided wave inspection is a new emerging technology for rapidly and globally inspecting a large area of a structure from a single test location. This paper describes a general overview of the guided wave properties and its application for long-range inspection of structures the principle and instrument system for a guided wave inspection technology called "magnetostrictive sensor (MsS)" that generates and detects guided waves electromagnetically in the material under testing, and examples of long-range guided wave inspection of structures that can be accomplished using the MsS.

• 환경영향평가
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• 제16권1호
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• pp.89-98
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• 2007

In order to conduct the environmental assessment of long range transboundary air pollutants over East Asia, the moving pathways of air pollutants are of great importance, which are depending upon the meteorological weather patterns. Therefore regional scale modeling study requires the identified geopotential height distribution patterns to deal with behaviors of long range transport air pollutants for the effective long term atmospheric environmental assessment. In this study the synoptic meteorological classification using cluster analysis technique over Northeast Asia, and its previous applications of the regional scale air pollutant modeling studies were reviewed and summarized in detail. Other synoptic meteorological characteristics over Korean peninsula are also discussed.

• 국제초고층학회논문집
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• 제5권3호
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• pp.177-186
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• 2016

Along the subduction-zone of the western Japanese islands, large earthquakes are expected occur around the middle of this century, and long-period ground motions will reach major urban areas, shaking high-rise buildings violently. Since some old high-rise buildings were designed without considering long-period ground motions, reinforcing such buildings is an important issue. An effective method to reinforce existing high-rise buildings is installing additional dampers. However, a problem with ordinary dampers is that they require reinforcement of surrounding columns and girders to support large reaction forces generated during earthquake ground motion. To solve this problem, a deformation-dependent oil damper was developed. The most attractive feature of this damper is to reduce the damping force at the moment when the frame deformation comes close to its maximum value. Due to this feature, the reinforcement of columns, girders, and foundations are no longer required. The authors applied seismic retrofitting with a deformation-dependent oil damper to an existing 54-story office building (Shinjuku Center Building) located in Shinjuku ward, Tokyo, in 2009 to suppress vibration under the long period earthquake ground motions. The seismic responses were observed in the 2011 Tohoku Earthquake, and it is clarified that the damping ratio was higher and the response lower by 20% as compared to the building without dampers.

• Ocean and Polar Research
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• 제25권spc3호
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• pp.385-392
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• 2003

A new type of soft ground breakwater was recently developed, which does not need ground improvement because of light weight and structural characteristics. The various studies about consolidation settlements and lateral behavior of proposed soft ground breakwater have been conducted. But, the systematic investigations on the construction performance and long-term settlements of new type breakwater has not been accomplished. In this study, construction simulation of soft ground breakwater with soil box model test and experiments of the long-term wave loaded breakwater were performed. The results of test shows that it is possible to compensate differential settlements by dead loading and/or suction pressure, and to reduce the consolidation settlements by preloading method. It was also found that the vertical and lateral displacements of long-term wave loaded breakwater were negligible.

• 한국보건간호학회지
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• 제24권2호
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• pp.211-225
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• 2010

Purpose: This comparative study analyzed information systems including manpower, contents of service, clients, and costs among four nations. Methods: A literature review of relevant publications from Korea, United States, Japan, and Germany supported the use of several plans to activate home nursing care services under the long-term care insurance system in Korea. Results: Korean home nursing care services require quality improvements. The results indicated that a rule is necessary that rations simple visiting service and home nursing care services under the long-term care insurance system, that an integrated management system for elderly care is required, and that the revised delivery of services needs to establish and reflect on various factors to estimate the value in a home visiting nursing care cost system. Conclusion: The data should be valuable in establishment of home nursing care services under the long-term insurance system in Korea.