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      • SCOPUSKCI등재

        Changes of Landscape Structure for the Recent 20 Years in the Wangsuk Stream Basin of the Central Korea

        Lee, Chang-Seok,Cho, Yong-Chan,Shin, Hyun-Chul,Lee, Seon-Mi The Ecological Society of Korea 2006 Journal of Ecology and Environment Vol.29 No.4

        Landscape changes for 20 years between 1981 and 2001 in the Wangsuk stream basin located on the central Korea were investigated on the basis of physiognomic vegetation map made from the aerial photograph interpretation and field check. Changes of landscape structure were noticeable in agricultural field and forest landscape elements. Changes in the agricultural fields due to transformation of agricultural pattern into the institutional agriculture dominated landscape change, although urbanization also contributed to such change. The former change due to change of food production structure originated from socio-economic development during this period and the latter to the overpopulation of Seoul. As energy sources for heating and cooking, fertilizer, and fodder for livestock transform from plant materials to fossil fuel, manufactured one, and grain, succession of forest escaped from direct human disturbance dominated change of landscape structure in forested land. Differently from the positive landscape change in the upper area, change in the lower area deteriorated landscape quality by increasing artificial land. It was estimated that such landscape deterioration in the Wangsuk stream basin would influence water quality of the stream. In order to realize sustainable land-use against such environmental degradation, systematic environmental management based on landscape ecological perspective such as "an eco-plan for creating riparian vegetation belt," which is under preparation by Ministry of Environment, was recommended.

      • 심실근의 수축현상에 미치는 O₂, CO₂ 및 pH의 영향

        장석종,박해근 충남대학교 의과대학 지역사회의학연구소 1983 충남의대잡지 Vol.10 No.2

        It has been well known that increased hydrogen ion concentration causes the negative inotropic effect on the heart. But in the status of acid base imbalance, metabolic or respiratory, the question of which status has more profound effect on the cardiac muscle contractility remains unsolved. Furthermore, whether such effect is attributable to the change of the intracellular pH or the extracellular change is a matter of controversy. In many studies concerning to the effect of carbon dioxide tension on the cardiac contractility, the effect of excess oxygen has been ignored despite of its significant influence upon the cellular function. The author intended to investigate the effects of the change of carbon dioxide tension, which causes the pH change simultaneously, as well as the effect of excess oxygen on the cardiac ventricular contractility. Also, to prove which change, metabolic or respiratory, has more profound effect and which change, intracellulcr or extracellular, has more crucial effect, the author examined the contractility of the ventricle under two different conditions. They were as follows: a) PCO_2 was varying despite of same magnitude of the change in pH. b) pH was varying despite of the same magnitude of the change in PCO_2 Turtle hearts were used and the Langendorf preparations were made. The perfusate was Tris-buffer solution for turtle, saturated with various gases, such as air, pure oxygen, nitrogen, or different concentrations of CO_2 balanced with oxygen or nitrogen. The tension and maximal dT/dt were recorded with the Physiograph and its accessories. The results were summarized as follows. 1. The excess oxygen enhanced the ventricular contractility. 2. Increased carbon dioxide tension, which decreases the pH simultaneously, reduced the ventricular contractility and that was more pronounced when CO_2 was balanced with nitrogen gas rather than with oxygen gas. 3. The relationships among several physiological parameters were estimated as follows: a) Y=1.01X-0.56 X: percent change of the tension Y: percent change of maximal contration dT/dt b) Z=1.06X-4.56 Z: percent change of maximal relation dT/dt The corelation coefficient in a) is 0.939 and in b) is 0.926, being significant statistically (P<0.005). 4. When the change of pH were same but the changes of PCO_2 were different, the change of ventricular contractility was more profound in the respiratory decrease of pH, that was higher PCO_2, more depressing effect (P<0.005) was manifested, than in the case of metabolic origin (p<0.005). 5. When the changes of PCO_2 were same but the changes of pH were different, the influence of the latter parameter on the contractility was not significant (P<0.1). From the above results it was suggested that the increased PCO_2, which also causes the decrease of pH, has negative inotropic effect and excess oxygen has positive inotropic effect on the ventricular muscle of the turtle. The negative inotropic effect of the lowered pH on the ventricular muscle was revealed to be more profound when it was induced by respiratory distress rather than motabolic and may be affected by change of intracellular pH rather than extracellular pH.

      • SCOPUSKCI등재

        Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

        Cho, Yong-Chan,Lee, Chang-Seok,Cho, Hyun-Je,Lee, Kyu-Song,Park, Pil-Sun The Ecological Society of Korea 2011 Journal of Ecology and Environment Vol.34 No.1

        Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.

      • Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

        Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

        <P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

      • KCI등재

        기후변화가 축산업에 미치는 경제효과

        공현석(Hyeon Seok Gong),정경수(Kyeong Soo Jeong),김민경(Min Kyoung Kim),장재봉(Jae Bong Chang) 한국농식품정책학회 2020 농업경영정책연구 Vol.47 No.2

        Adopting the Ricardian approach, this study investigates the economic effects of climate changes such as average temperature and rainfalls on Korean livestock farm revenue. The explanatory variables of empirical model were selected based on the previous literature. The pseudo-panel analysis is employed to resolve the imperfectness of the panel data. The results indicate that the control variables such as farming experience, household size, employment, ownership of heavy machinery, technology use, full-time farming and male owner affect the livestock farm revenue positively, and the age does negatively. The impact of summer average temperature on farm revenue was significant and negative, while that of winter was significant and positive. The marginal change of the summer temperature decrease farm revenue per head by 2.48%. This paper suggests that the livestock farm’s revenue responds sensitively to changes in summer and winter average temperature, and so we need to establish the long-term countermeasures against rapid climate change.

      • SCOPUSKCI등재

        Which Environmental Factors Caused Lammas Shoot Growth of Korean Red Pine?

        Lee, Chang-Seok,Song, Hye-Gyung,Kim, Hye-Soo,Lee, Bit-Na-Ra,Pi, Jeong-Hoon,Cho, Yong-Chan,Seol, Eun-Sil,Oh, Woo-Seok,Park, Sung-Ae,Lee, Seon-Mi The Ecological Society of Korea 2007 Journal of Ecology and Environment Vol.30 No.1

        Lammas growth, a rare phenomenon for Korean red pine (Pinus densiflora), occurred in 2006. Lammas shoots showed higher frequency and longer length in Seoul's hotter urban center than in urban boundary or suburban forest sites. Frequency and length showed a close correlation with urbanization density and vegetation cover expressed in NDVI. Air temperature in the late summer of 2006 was more than $1^{\circ}C$ higher than an average year. Of the predominant environmental signals that modulate bud flush, only temperature changed significantly during the year. Differences in temperature between the urban centers, urban boundaries and suburban forests correlated with varying land-use density. The rise in temperature likely spurred lammas growth of the Korean red pine. Symptoms of climate change are being detected throughout the world, and its consequences will be clearer in the future. Considerate interest in the responses of ecological systems to the variable changes is required to prepare for unforeseeable crises. Monitoring of diverse ecological phenomena at Long Term Ecological Research sites could offer harbingers of change.

      • KCI등재

        시공간 지각 단서에 의한 단일체(單一體)의 가변적 형태 변화

        신석규(Seok Kyu Shin),장욱선(Uk Sun Chang) 한국디자인문화학회 2010 한국디자인문화학회지 Vol.16 No.2

        존재하는 모든 사물과 현상은 시간의 흐름과 무한한 공간의 틀 속에서 운행한다. 사물의 변화를 느끼게 되는 것은 시간과 공간이 있기 때문이다. 시간과 공간은 존재를 증명하는 기본적 개념으로 인식의 태도는 고정된 정형성의 관점을 벗어난다. 본 연구는 시공간 지각 단서를 기초로 하여 아이덴티티 디자인의 시스템 운용 체계를 중심으로 심볼마크가 상징하고 있는 정체성의 근원을 밝힘으로써 다양하게 응용되고 있는 단일체의 가변적 형태들의 실효성을 검증하고자 했다. 시공간 지각 단서는 선행연구인 "2차원의 평면에서 작용하는 시공간의 지각적 무브망"에서 제시한 시간의 연속체-류, 수, 질, 공간의 확장세-실, 허, 장, 시공복합체의 유기-합, 초, 재로 구분한 분류 체계를 근간으로 설명했으며, 단일체의 가변적 형태변화는 본질적 대상, 즉 단일체의 확장에 의한 것으로 원래의 상태로 되돌아갈 수 있는 상태, 또는 처음의 그 상태로서 원래의 대상물을 지칭하는 것을 의미한다. 이러한 가변적 형태변화에 대한 분류와 설명을 위해 압축, 변이, 파생의 세 가지 대분류를 전제하고 각각의 개념을 재정립하였다. 또한, 단일체의 응용방법에 따라 조형적, 역동적, 조직적인 부분으로 구분하여 연구의 체계성을 확보했다. 단일체의 가변적 형태 변화는 첫째, 결합과 통합의 과정을 거치면서 핵심만을 나타내게 되는 방식으로 설명되는 조형적 형태압축, 둘째, 하나의 단일체가 변화해 가는 일련의 과정 및 변화된 형태의 역동적 형태변이, 셋째, 추가적인 개념이나 시각적 형태가 부가되거나 결합의 과정을 거쳐 새로운 형태가 나타나는 조직적 형태파생으로 설명할 수 있다. 시공간 지각 단서에 의해 지각되는 심볼들이 단순성과 조형성만을 고려한 평면적인 심볼들과 시각이미지의 지각과 인지에서 상반될 수 있는 논리적 근거는 단일체의 가변적인 형태 변화에 있으며 이는 시지각의 차원에서 더 역동적이고 진취적인 유기체로서의 생동감있는 이미지를 전달할 수 있다. 단일체의 가변적 형태 변화를 추구한 아이덴티티 디자인 시스템은 다변화하는 뉴 미디어 시대에서 커뮤니케이션의 변화된 흐름을 주도하는 새로운 시각적 정체성을 보여준다. 상징의 근원적 체계화, 시스템의 창조적 확장성과 미디어에 대응한 운용체계로 인해 기업이미지와 브랜드 이미지 체계를 구축하는 데 있어 고도의 전략적 수단으로 활용될 수 있으며 미래 아이덴티티 디자인의 가치를 한 단계 상승시킬 수 있는 새로운 개발 시스템이 될 수 있을 것이다. All existing objects run within a frame of flowing time and infinite space. Changes in objects are sensed due to the existence of time and space. Space and time are the basic concepts that prove existence, and the manner of awareness breaks away from fixed and formulated perceptions. This study aims to verify the effectiveness of diversely applied variable forms of monolithic objects by discovering the source of the identity symbolized by symbol marks, based on space time perception clues and centered around design systems` operating systems. Space time perception clues were explained on the basis of the `continuum of time - stream, numbers, origin, expansion of space-fullness, voidness, field, Organism of Time & Space agglomeration-convergence, transcendental, existence` classification system as proposed in the precedent study, "Perceptional Mouvement of Time and Space Act on Two-Dimensional Plane". Monolithic object variable form change is caused by the expansion of the fundamental object, the monolithic object, and means the designation of the original object as the condition that allows it to return to its original state, or its original condition. To classify and explain such variable form change, 3 large classification of Compression, Variation, and Derivation were assumed, and each concept was reestablished. Also, the single bodies were classified into formative, dynamic, or systematic according to application methods in order to secure the study`s systemicity. Monolithic object variable form change can be explained in the following three ways: 1. Formative form compression, explained by the method of only the cores being revealed following a process of fusion and integration 2. A series of monolithic object change processes and the dynamic form variations the changed form undergoes 3. Systematic form derivation in which a new form emerges as a result of additional concepts and visual forms being added or fusion processes. The flat symbols that only take into account the simplicity and formativeness of symbols perceived by space time perception clues, and the theoretical basis that can conflict with visual image perception and recognition, are in monolithic object variable form change. This is an organism that is more dynamic and progressive compared to that in a dimension of visual perception, and can deliver life-like images.

      • Wi-Fi 핑거프린트 기반 실내 이동 경로 데이터 생성 방법

        윤창표(Chang-Pyo Yoon),황치곤(Chi-Gon Hwang) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.1

        최근, 실내 위치 기반 서비스에서 정확한 서비스를 위해 Wi-Fi 핑거프린트 기반의 딥러닝 기술을 이용한 연구가 이루어지고 있다. 딥러닝 모델 중에서 과거의 정보를 기억할 수 있는 RNN 모델은 실내측위에서 연속된 움직임을 기억할 수 있어 측위 오차를 줄일 수 있다. 이때 학습 데이터로서 연속적인 순차 데이터를 필요로 한다. 그러나 일반적으로 Wi-Fi 핑거프린트 데이터의 경우 특정 위치에 대한 신호들만으로 관리되기 때문에 RNN 모델의 학습데이터로 사용이 부적절하다. 본 논문은 RNN 모델의 순차적인 입력 데이터의 생성을 위해 클러스터링을 통한 영역 데이터로 확장된 Wi-Fi 핑거프린트 데이터 기반 이동 경로의 예측을 통한 경로 생성 방법에 대해 제안한다. Recently, researches using deep learning technology based on Wi-Fi fingerprints have been conducted for accurate services in indoor location-based services. Among the deep learning models, an RNN model that can store information from the past can store continuous movements in indoor positioning, thereby reducing positioning errors. At this time, continuous sequential data is required as training data. However, since Wi-Fi fingerprint data is generally managed only with signals for a specific location, it is inappropriate to use it as training data for an RNN model. This paper proposes a path generation method through prediction of a moving path based on Wi-Fi fingerprint data extended to region data through clustering to generate sequential input data of the RNN model.

      • Allogenic succession of Korean fir (<i>Abies koreana Wils.</i>) forests in different climate condition

        Lim, Chi Hong,An, Ji Hong,Jung, Song Hie,Lee, Chang Seok Springer Japan 2018 Ecological research Vol.33 No.2

        <P><B>Abstract</B></P><P>This study was conducted to clarify the changes in vegetation that occurred due to changing environmental factors, especially climate, at Korean fir (<I>Abies koreana</I>) stands with different climatic conditions established on Mt. Halla, which is located on a southern island of South Korea. The difference of species composition between sites was large and depended on elevation and slope aspect at lower elevations, whereas not as much among stands or between sites at the highest elevations of each slope aspect. It was interpreted that differences and similarities among sites were dominated by the microclimate determined by the topographic conditions of each site. The result of vegetation dynamics analysis predicted that the Korean fir forests would be replaced by temperate forests such as Mongolian oak (<I>Quercus mongolica</I>) forests or shade intolerant forests composed of early successional species such as Korean cherry (<I>Prunus maximowiczii</I>) and Spreading yew (<I>Taxus cuspidata</I>) at lower elevations, while would continuously persist at the highest elevations. We interpreted the vegetation changes appeared at the lower elevations as an allogenic succession, as the recent rapid climate changes directly and indirectly dominated the change. The species distribution modeling predicted that the distributional range of Korean fir would decrease to 13.4 and 10.1% of the current distribution in 2050 and 2070, respectively. Further, the distribution modeling showed that the sites located at lower elevations would no longer be within the distributional range of Korean fir forest, and those at the highest elevations would be sparsely scattered in fragmented states.</P>

      • Biomechanical analysis of lumbar decompression surgery in relation to degenerative changes in the lumbar spine – Validated finite element analysis

        Li, Quan You,Kim, Ho-Joong,Son, Juhyun,Kang, Kyoung-Tak,Chang, Bong-Soon,Lee, Choon-Ki,Seok, Hyun Sik,Yeom, Jin S. Elsevier 2017 Computers in biology and medicine Vol.89 No.-

        <P><B>Abstract</B></P> <P><B>Background</B></P> <P>There are no studies about the biomechanical analysis of lumbar decompression surgery in relation to degenerative changes of the lumbar spine. Therefore, the purpose of this study was to compare, by using finite element (FE) analysis, the biomechanical changes of the lumbar spine in terms of annulus stress and nucleus pressure after two different kinds of lumbar decompression surgery in relation to disc degenerative changes.</P> <P><B>Methods</B></P> <P>The validated intact and degenerated FE models (L2-5) were used in this study. In these two models, two different decompression surgical scenarios at L3-4, including conventional laminectomy (ConLa) and the spinous process osteotomy (SpinO), were simulated. Therefore, a total of six models were simulated. Under preloading, 7.5 Nm moments of flexion, extension, lateral bending, and torsion were imposed. In each model, the maximal von Mises stress on the annulus fibrosus and nucleus pressure at the index segment (L3-4) and adjacent segments (L2-3 and L4-5) were analyzed.</P> <P><B>Results</B></P> <P>The ConLa model and disc degeneration model demonstrated a larger annulus stress at the decompression level (L3-4) under all four moments than were seen in the SpinO model and healthy disc model, respectively. Therefore, the ConLa model with moderate disc degeneration showed the highest annulus stress at the decompression level (L3-4). However, the percent change of annulus stress at L3-4 from the intact model to the matched decompression model was less in the moderate disc degeneration model than in the healthy disc model.</P> <P><B>Conclusions</B></P> <P>Although the ConLa model with moderate disc degeneration showed the highest annulus stress, the degenerative models would be less influenced by the decompression technique.</P>

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