• Title/Summary/Keyword: K-Motion

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Cyclic Igneous Activities During the Late Paleozoic to Early Cenozoic Period Over the Korean Peninsula (고생대말-신생대초 기간에 일어난 한반도의 주기적 화성활동)

  • Park, Kye-Hun
    • The Journal of the Petrological Society of Korea
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    • v.21 no.2
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    • pp.193-202
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    • 2012
  • There were three cycles of igneous activities from the late Paleozoic to early Cenozoic; Permian to Triassic, Jurassic, and Cretaceous to Paleogene. After the beginning of each igneous activity cycle, igneous activity became more frequent until its climax. It is noteworthy that A-type magmatisms are reported from near the ends of the all three igneous activity cycles. In addition, adakitic magmatisms occurred at the beginning of both the Permian-Triassic and the Cretaceous-Paleogene cycles. Most of the igneous activities during the late Paleozoic to early Cenozoic period were subduction-related. Therefore, transitions among beginning, proceeding, and closing of the igneous activity cycles would be intimately related with changes in directions of plate movements. In this context, I suggest following hypotheses. The closing of the Permian-Triassic igneous cycle was possibly a consequence of radical adjustment of plate motion occurred due to continental collision between north and south China blocks. Considering that no appreciable tectonic activities were recognized from the east Asian continent at the closing of the Jurassic igneous cycle, it seems that one of the strong events related with Gondwanaland-breakup and subsequent birth of the new oceans, which might cause sudden adjustments of plate motions. The closing of the Cretaceous-Paleogene igneous cycle seems to be caused as a consequence of the collision between India and Asia continents. Meanwhile, adakitic igneous bodies emplaced at the beginnings of the Permian-Triassic and Cretaceous-Paleogene cycles could be products of slab-melting during the early stages of the subduction.

Rheological Characteristics and Debris Flow Simulation of Waste Materials (광산폐석의 유변학적 특성과 토석류 흐름특성 분석)

  • Jeong, Sueng Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.4
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    • pp.1227-1240
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    • 2014
  • Abandoned mines often cause environmental problems, such as alteration of landscape, metal contamination, and landslides due to a heavy rainfall. Geotechnical and rheological tests were performed on waste materials corrected from Imgi waste rock dump, located in Busan Metropolitan City. Debris flow mobility was examined with the help of 1-D BING model which was often simulated in both subaerial and subaqueous environments. To determine flow curve, we used a vane-penetrated rheometer. The shear stress (${\tau}$)-shear rate (${\dot{\gamma}}$) and viscosity(${\eta}$)-shear rate (${\dot{\gamma}}$) relationships were plotted using a shear stress control mode. Well-known rheological models, such as Bingham, bilinear, Herschel-Bulkley, Power-law, and Papanastasiou concepts, were compared to the rheological data. From the test results, we found that the tested waste materials exhibited a typical shear shinning behavior in ${\tau}$-${\dot{\gamma}}$ and and ${\eta}$-${\dot{\gamma}}$ plots, but the Bingham behavior is often observed when the water contents increased. The test results show that experimental data are in good agreement with rheological models in the post-failure stage during shearing. Based on the rheological properties (i.e., Bingham yield stress and viscosity as a function of the volumetric concentration of sediment) of waste materials, initial flowing shape (5 m, 10 m, and 15 m) and yield stress (100 Pa, 200 Pa, 300 Pa, and 500 Pa) were input to simulate the debris flow motion. As a result, the runout distance and front velocity of debris flow are in inverse propositional to yield stress. In particular, when the yield stress is less than 500 Pa, most of failed masses can flow into the stream, resulting in a water contamination.

Prevalence and Factors Associated with Smoking Intentions among Non-smoking and Smoking Adolescents in Kota Tinggi, Johor, Malaysia

  • Hock, Lim Kuang;Ghazali, Sumarni Mohamad;Cheong, Kee Chee;Kuay, Lim Kuang;Li, Lim Hui;Huey, Teh Chien;Ying, Chan Ying;Yen, Yeo Lay;Ching, Fiona Goh Swee;Yi, Khoo Yi;Lin, Chong Zhuo;Ibrahim, Normala;Mustafa, Amal Nasir
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4359-4366
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    • 2014
  • Intention to smoke is a valid and reliable factor for predicting future smoking habits among adolescents. This factor, however, has received inadequate attention in Malaysia. The present paper elaborates the prevalence and factors associated with intent to initiate or to cease smoking, among adolescent nonsmokers and smokers in Kota Tinggi, Johor, Malaysia. A total of 2,300 secondary school students aged 13-16 years were selected through a two-stage stratified sampling method. A set of standardized questionnaires was used to assess the smoking behavior among adolescents and the inter-personal and intra-personal factors associated with smoking intention (intention to initiate smoking or to cease smoking). Multivariable logistic regression was used to identify factors related to smoking intention. The prevalence of intention to smoke in the future or to cease smoking among non-smoking adolescents and current smokers were 10.7% and 61.7% respectively. Having friends who smoke, social influence, and poor knowledge about the ill effects on health due to smoking showed significant relationships with intention to smoke in the future among non-smokers. Conversely, perceived lower prevalence of smoking among peers, weak contributory social influence, and greater awareness of the ill effects of smoking are factors associated with the intention to cease smoking sometime in the future. The study found that prevalence of intention to initiate smoking is low among non-smokers while the majority of current smokers intended to cease smoking in the future. Existing anti-smoking programmes that integrate the factors that have been identified in the current study should be put in motion to reduce the prevalence of intention to initiate smoking and increase the intention to cease smoking among adolescents.

Numerical Study on the Development of the Seismic Response Prediction Method for the Low-rise Building Structures using the Limited Information (제한된 정보를 이용한 저층 건물 구조물의 지진 응답 예측 기법 개발을 위한 해석적 연구)

  • Choi, Se-Woon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.33 no.4
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    • pp.271-277
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    • 2020
  • There are increasing cases of monitoring the structural response of structures using multiple sensors. However, owing to cost and management problems, limited sensors are installed in the structure. Thus, few structural responses are collected, which hinders analyzing the behavior of the structure. Therefore, a technique to predict responses at a location where sensors are not installed to a reliable level using limited sensors is necessary. In this study, a numerical study is conducted to predict the seismic response of low-rise buildings using limited information. It is assumed that the available response information is only the acceleration responses of the first and top floors. Using both information, the first natural frequency of the structure can be obtained. The acceleration information on the first floor is used as the ground motion information. To minimize the error on the acceleration history response of the top floor and the first natural frequency error of the target structure, the method for predicting the mass and stiffness information of a structure using the genetic algorithm is presented. However, the constraints are not considered. To determine the range of design variables that mean the search space, the parameter prediction method based on artificial neural networks is proposed. To verify the proposed method, a five-story structure is used as an example.

Analysis of Characteristics of Seismic Source and Response Spectrum of Ground Motions from Recent Earthquake near the Backryoung Island (최근 백령도해역 발생지진의 지진원 및 응답스펙트럼 특성 분석)

  • Kim, Jun-Kyoung
    • Geophysics and Geophysical Exploration
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    • v.14 no.4
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    • pp.274-281
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    • 2011
  • We analysed ground motions form Mw 4.3 earthquake around Backryoung Island for the seismic source focal mechanism and horizontal response spectrum. Focal mechanism of the Backryoung Islands area was compared to existing principal stress orientation of the Korean Peninsula and horizontal response spectrum was also compared to those of the US NRC Regulatory Guide (1.60) and the Korean National Building Code. The ground motions of 3 stations, including vertical, radial, and tangential components for each station, were used for grid search method of moment tensor seismic source. The principal stress orientation from this study, ENE-WSW, is consistent fairly well with that of the Korean Peninsula. The horizontal response spectrum using 30 observed ground motions analysed and then were compared to both the seismic design response spectra (Reg Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings (1997). Response spectrum of 30 horizontal ground motions were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that the horizontal response spectrum revealed higher values for frequency bands above 3 Hz than Reg. Guide (1.60). The results were also compared to the Korean Standard Response Spectrum for the 3 different soil types and showed that the vertical response spectra revealed higher values for the frequency bands below 0.8 second than the Korean Standard Response Spectrum (SD soil condition). However, through the qualitative improvements and quantitative enhancement of the observed ground motions, the conservation of horizontal seismic design response spectrum should be considered more significantly for the higher frequency bands.

Behavior Characteristics of Micropile Following the Embedded Condition (근입조건에 따른 마이크로파일의 거동특성)

  • Bang, Seongtaek
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.6
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    • pp.19-25
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    • 2020
  • In the recent downtown works, there are frequent cases where the work on existing piles is impossible due to the influence from lack of space and surrounding environment. In such cases, there has been growing cases of using the micropile method that is available to work with the small equipment and asserts the bearing capacity of the existing piles. The micropile method is a type of drilled shaft with the diameter of a pile to be around 75 mm~300 mm that, even for a case where it has certain surrounding structure, foundation and spatial obstacle, there is almost no work difficulty and the work is feasible under all types of soil conditions. In addition, the work can be done in places where the ceiling of the building is low with less vibration and noise in the work process that such method is significantly used for foundation reinforcement of existing buildings. With respect to the motion characteristics that are changed depending on the foundational characteristics or when the micropile is applied with compression or tensile force, there is very few studies conducted. Therefore, under this study, through the data analysis of the field loading test regarding the micropile worked in the fields, it clarifies the settlement and characteristics of bearing capacity following the embedded condition of the ingredients and piles that consist the foundation if the compression and tensile force are applied to the micropile, and by facilitating the statistical analysis program, SAS, to carry out the analysis on the main elements influencing on settlement of the micropile and bearing capacity.

Semiotic Approach to the Representation Process of Time in Cinema (영화의 시간성 표현을 위한 기호학적 모델의 제언 -들뢰즈 "운동-이미지"의 기호화 과정을 중심으로-)

  • Kim, Byoung-Sun
    • Korean journal of communication and information
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    • v.26
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    • pp.7-44
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    • 2004
  • This paper proposed semiotic model to explain representation process of time in cinema. Limitations of cinematic narratology which explain representation process of time in cinema were indicated, then alternative explanations of Deleuzian philosophy of cinema were proposed. After discussion about articulations of cinematic code, Deleuzian concept of movement-image was suggested as semiotic minimal unit of cinema. In cinema, Movement-image is divided two different aspects ; "normal movement-image" and "abnormal movement-image". Therefore, two different semiotic representation process of time was reconstructed in accordance with Peircean semiosis theory. In this two different semiotic process, modern cinema emphasize the direct representation process of time with "abnormal movement-image". As Deleuze indicated, The "time-image" is presented in this semiotic process. The "time-image" makes it possible to consider "time itself" as philosophical fact which is laid between reality and cinema, This semiotic process more emphasizes pure expressionality than representationality. Deleuzian philosophical journey through cinema was started in this point.

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Exploring Teaching Method for Productive Knowledge of Scientific Concept Words through Science Textbook Quantitative Analysis (과학교과서 텍스트의 계량적 분석을 이용한 과학 개념어의 생산적 지식 교육 방안 탐색)

  • Yun, Eunjeong
    • Journal of The Korean Association For Science Education
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    • v.40 no.1
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    • pp.41-50
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    • 2020
  • Looking at the understanding of scientific concepts from a linguistic perspective, it is very important for students to develop a deep and sophisticated understanding of words used in scientific concept as well as the ability to use them correctly. This study intends to provide the basis for productive knowledge education of scientific words by noting that the foundation of productive knowledge teaching on scientific words is not well established, and by exploring ways to teach the relationship among words that constitute scientific concept in a productive and effective manner. To this end, we extracted the relationship among the words that make up the scientific concept from the text of science textbook by using quantitative text analysis methods, second, qualitatively examined the meaning of the word relationship extracted as a result of each method, and third, we proposed a writing activity method to help improve the productive knowledge of scientific concept words. We analyzed the text of the "Force and motion" unit on first grade science textbook by using four methods of quantitative linguistic analysis: word cluster, co-occurrence, text network analysis, and word-embedding. As results, this study suggests four writing activities, completing sentence activity by using the result of word cluster analysis, filling the blanks activity by using the result of co-occurrence analysis, material-oriented writing activities by using the result of text network analysis, and finally we made a list of important words by using the result of word embedding.

Current Status of Imaging Physics & Instrumentation In Nuclear Medicine (핵의학 영상 물리 및 기기의 최신 동향)

  • Kim, Hee-Joung
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.2
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    • pp.83-87
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    • 2008
  • Diagnostic and functional imaging device have been developed independently. The recognition that combining of these two devices can provide better diagnostic outcomes by fusing anatomical and functional images. The representative examples of combining devices would be PET/CT and SPECT/CT. Development and their applications of animal imaging and instrumentation have been very active, as new drug development with advanced imaging device has been increased. The development of advanced imaging device resulted in researching and developing for detector technology and imaging systems. It also contributed to develop a new software, reconstruction algorithm, correction methods for physical factors, image quantitation, computer simulation, kinetic modeling, dosimetry, and correction for motion artifacts. Recently, development of MRI and PET by combining them together was reported. True integration of MRI and PET has been making the progress and their results were reported. The recent status of imaging and instrumentation in nuclear medicine is reported in this paper.

Estimation of source signal and channel response using ray-based blind deconvolution technique for Doppler-shifted underwater channel (음선 기반 블라인드 디컨볼루션 기법을 이용한 수중 도플러 편이 채널에서의 송신 신호 및 채널 응답 추정)

  • Byun, Gi Hoon;Oh, Se Hyun;Byun, Sung-Hoon;Kim, J.S.
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.5
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    • pp.331-339
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    • 2016
  • This paper suggests an estimation method of the source signal and the channel impulse response (CIR) using ray-based blind deconvolution (RBD) in the underwater acoustic channel environment where Doppler effect exists by the relative motion between source and receiver. It is difficult to estimate the CIR on Doppler effect by the matched filter with a highly Doppler-sensitive waveform such as the m-sequence signal because Doppler shift can severely degrade the correlation between the received signal corrupted by Doppler effect and the original source signal. In this study, the Doppler-shifted source-signal's phase is estimated using the RBD, and the received signal is compensated by it to obtain the Doppler-corrected CIR. It is verified that using the matched filter with the received signal from the experimental data fails to estimate the CIR while the obtained CIR by the suggested method has the similarity to the propagation path of the ray model. Also, the results show that the reconstructed source signal using the RBD has the better Doppler shift compensation than the Doppler-shifted source signal derived from scattering function.