• 제목/요약/키워드: history of science and technology

검색결과 921건 처리시간 0.026초

Detection for Operation Chain: Histogram Equalization and Dither-like Operation

  • Chen, Zhipeng;Zhao, Yao;Ni, Rongrong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권9호
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    • pp.3751-3770
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    • 2015
  • Many sorts of image processing software facilitate image editing and also generate a great number of doctored images. Forensic technology emerges to detect the unintentional or malicious image operations. Most of forensic methods focus on the detection of single operations. However, a series of operations may be used to sequentially manipulate an image, which makes the operation detection problem complex. Forensic investigators always want to know as much exhaustive information about a suspicious image's entire processing history as possible. The detection of the operation chain, consisting of a series of operations, is a significant and challenging problem in the research field of forensics. In this paper, based on the histogram distribution uniformity of a manipulated image, we propose an operation chain detection scheme to identify histogram equalization (HE) followed by the dither-like operation (DLO). Two histogram features and a local spatial feature are utilized to further determine which DLO may have been applied. Both theoretical analysis and experimental results verify the effectiveness of our proposed scheme for both global and local scenarios.

New method for generation of artificial ground motion by a nonstationary Kanai-Tajimi model and wavelet transform

  • Amiri, G. Ghodrati;Bagheri, A.;Fadavi, M.
    • Structural Engineering and Mechanics
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    • 제26권6호
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    • pp.709-723
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    • 2007
  • Considering the vast usage of time-history dynamic analyses to calculate structural responses and lack of sufficient and suitable earthquake records, generation of artificial accelerograms is very necessary. The main target of this paper is to present a novel method based on nonstationary Kanai-Tajimi model and wavelet transform to generate more artificial earthquake records, which are compatible with target spectrum. In this regard, the generalized nonstationary Kanai-Tajimi model to include the nonstationary evaluation of amplitude and dominant frequency of ground motion and properties of wavelet transform is used to generate ground acceleration time history. Application of the method for El Centro 1940 earthquake and two Iranian earthquakes (Tabas 1978 and Manjil 1990) is presented. It is shown that the model and identification algorithms are able to accurately capture the nonstationary features of these earthquake accelerograms. The statistical characteristics of the spectral response of the generated accelerograms are compared with those for the actual records to demonstrate the effectiveness of the method. Also, for comparison of the presented method with other methods, the response spectra of the synthetic accelerograms compared with the models of Fan and Ahmadi (1990) and Rofooei et al. (2001) and it is shown that the response spectra of the synthetic accelerograms with the method of this paper are close to those of actual earthquakes.

우리나라 학생 건강관리 사업의 역사적 변천과 의의: 2001~2010년 사업을 중심으로 (Historical Change and Significance of Health Management Programs for Korean Students: Based on Data from 2001 to 2010 Year)

  • 김현숙;길미경
    • 한국학교보건학회지
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    • 제26권3호
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    • pp.144-157
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    • 2013
  • Purpose: Health management programs should provide comprehensive health services for students and staffs at schools. Health management programs are critical for helping students become adults with physically, mentally, and socially good health conditions. The aim of this study was to identify the past and present history of health management programs and health laws to help schools develop future health plans. Methods: This study was conducted by analyzing reference data collected using data from Ministry of Education and Science Technology, Korean Educational Development Institute, Korea Centers for Disease Control and Prevention, and National Statistical Office as well as legal documents from the Legislative Office related to school health from 2001 to 2010. Results: Health management programs in schools included three sections: disease prevention and control, physical examinations, and prevention of communicable diseases. Disease prevention and controls consisted of obesity control, drug abuse prevention and control,and management of students' mental health. Various strategies and services were developed to improve health status of students for 10 years from 2001 to 2010. School health laws and systems have been established for disease prevention, physical examinations and communicable disease control as well, to improve students' health as well. Conclusion: The history of health management programs has a number of implications to help design future plans for school health programs and services for students and staffs.

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Planning and Design of Quingming Shanghe Park in Kaifeng

  • Liu, Xiao-ming
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • 제1호
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    • pp.202-207
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    • 2001
  • Covering an area of about 39 ha, Qingming Shanghe Park is located in the northwest of Kaifeng, formerly the capital of seven dynasties in China. It is intended to serve as a tourist attraction based on a painting 〃Qingming Festival at Riverside〃 by Zhang Zeduan of the Northern song Dynasty, which vividly illustrates a real life on the both sides of the Bian River as well as in the urban area, Kaifeng, in early Spring. The park is a collection of varied buildings such as shops, restaurants, tea-houses, theaters, and hotels in the North song style, with an introduction of the history of Kaifeng, this paper examines design philosophy and methodology of the park, and discusses the creative design of the first stage development known as known as The South Area of the park. Marked by the Rainbow Bridge and the City Gate, the South Area is divided into three parts, the rural, suburban, and urban parts which are organized according to the spatial order showed in the painting. The South Area proves to be very successful because of its amazing sense of history and interesting folk performance. Furthermore, the preliminary 9planning of the second stage development known as The North Area is presented with references to culture, history and customs. The North Area is proposed to include the Old Sports & Games Garden, the Exhibition Garden, and the Hot Spring Garden with an appearance of the imperial gardens in the Northern Song, integrated with participation of old sports and games, display of old science & technology achievements, and enjoyment of hot spring bath.

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디지털아트에 의한 패션일러스트레이션의 소프트웨어 미학 분석 - 아인슈타인의 상대성이론을 중심으로 - (Aesthetic Analysis of Digital Art Using Fashion Illustration Software - Focusing on Alfred Einstein's Theory of Relativity -)

  • 오은경;곽태기
    • 복식
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    • 제60권3호
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    • pp.26-43
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    • 2010
  • The inflow of digital technology into the art, especially in the Fashion Illustration since 1990, makes the new aesthetics of the beginning of the 21 century which the Software aesthetics can be called. The meeting of technology and the art make us recall a great scientist and artist, Leonardo da Vinci in the Renaissance that the notion of the art and skill was unified, same as the ancient history. This study is purposed to expand the concept of the art for the broad exchange of the digital technology and art and for the extensive expression method of the modern fashion illustration. Having views on science theory of the beginning of the 20 century, Theory of Relativity which had given a lot of influence in the philosophy, the litterature and the art, as well as all the science, it makes a connection with the history of art in the beginning of the 20 century and the story of the digital art in the beginning of the 21 century. Firstly, the Fauvism and 2D is based on the expression of the glowing and bright color by the Principle of constancy of light velocity. Secondly, the Cubism and 3D is associated with the Special theory of relativity in the cyberspace which the space and the time are totally accorded. Thirdly, the Futurism and 4D is compared with the General theory of relativity which contains the material and the gravity. They are gradually evolved into the Interactive art and the Kinetic art by the digital technology in the profound cyberspace.

Settlement prediction for footings based on stress history from VS measurements

  • Cho, Hyung Ik;Kim, Han Saem;Sun, Chang-Guk;Kim, Dong Soo
    • Geomechanics and Engineering
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    • 제20권5호
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    • pp.371-384
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    • 2020
  • A settlement prediction method based on shear wave velocity measurements and soil nonlinearity was recently developed and verified by means of centrifuge tests. However, the method was only applicable to heavily overconsolidated soil deposits under enlarged yield surfaces. In this study, the settlement evaluation method was refined to consider the stress history of the sublayer, based on an overconsolidation ratio evaluation technique, and thereby incorporate irrecoverable plastic deformation in the settlement calculation. A relationship between the small-strain shear modulus and overconsolidation ratio, which can be determined from laboratory tests, was adopted to describe the stress history of the subsurface. Based on the overconsolidation ratio determined, the value of an empirical coefficient that reflects the effect of plastic deformation over the elastic region is determined by comparing the overconsolidation ratio with the stress increment transmitted by the surface design load. The refined method that incorporate this empirical coefficient was successfully validated by means of centrifuge tests, even under normally consolidated loading conditions.

Probabilistic seismic performance evaluation of non-seismic RC frame buildings

  • Maniyar, M.M.;Khare, R.K.;Dhakal, R.P.
    • Structural Engineering and Mechanics
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    • 제33권6호
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    • pp.725-745
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    • 2009
  • In this paper, probabilistic seismic performance assessment of a typical non-seismic RC frame building representative of a large inventory of existing buildings in developing countries is conducted. Nonlinear time-history analyses of the sample building are performed with 20 large-magnitude medium distance ground motions scaled to different levels of intensity represented by peak ground acceleration and 5% damped elastic spectral acceleration at the first mode period of the building. The hysteretic model used in the analyses accommodates stiffness degradation, ductility-based strength decay, hysteretic energy-based strength decay and pinching due to gap opening and closing. The maximum inter story drift ratios obtained from the time-history analyses are plotted against the ground motion intensities. A method is defined for obtaining the yielding and collapse capacity of the analyzed structure using these curves. The fragility curves for yielding and collapse damage levels are developed by statistically interpreting the results of the time-history analyses. Hazard-survival curves are generated by changing the horizontal axis of the fragility curves from ground motion intensities to their annual probability of exceedance using the log-log linear ground motion hazard model. The results express at a glance the probabilities of yielding and collapse against various levels of ground motion intensities.

Reproductive Phenology of Gracilaria verrucosa (Rhodophyta) in Cheongsapo near Pusan, Korea

  • Kim Young Sik;Choi Han Gil;Kim Hyung Geun;Nam Ki Wan;Sohn Chul Hyun
    • Fisheries and Aquatic Sciences
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    • 제1권1호
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    • pp.147-151
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    • 1998
  • The reproductive phenology of Gracilaria verrucosa was studied in Cheongsapo near Pusan, Korea. Among the life history phases, tetrasporic plants occurred dominantly in varying degrees of abundance throughout the year except from July to September. Cystocarpic plants increased rapidly during summer, and then recorded maximum abundance in July. Whereas, seasonal peaks of spermatangial plants were observed in April and September. However, they were less than cystocarpic plants in abundance. Vegetative plants dominated from December to May for long period, with a occurrence peak in February. Even though fertile plants in both gametophytes and tetrasporophytes occurred throughout the year, their seasonal abundance suggests that the positive correlation between reproduction and water temperature is basically found in the reproductive pattern of Gracilaria verrucosa. The distributional aspect of life history phases appears to be related with differences of their longevity, fecundity or survivorship.

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각시붕어(Rhodeus uyekii)와 흰줄납줄개(Rhodeus ocellatus) 잡종의 초기생활사 특징 (Early Life History Characteristics of an Induced Hybrid between Rhodeus uyekii and Rhodeus ocellatus)

  • 박재민;한경호
    • 한국수산과학회지
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    • 제52권4호
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    • pp.408-417
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    • 2019
  • This study was conducted to identify taxonomic differences in the characteristics of Rhodeus uyekii and Rhodeus ocellatus during their initial life history via an interspecific hybridization experiment. Hybrids were compared to their parent species, and the findings were used to inform developmental research in commercially useful aquarium fish. The hatching rates of the cross-bred eggs were 75.9% for cross UO (R. uyekii ♀${\times}$R. ocellatus♂) and 71.9% for cross OU (R. ocellatus♀${\times}$R. uyekii♂), which did not differ greatly from the hatching rates of the normal cross-bred group. Backcross experiments resulted in 100% egg mortality during development. Newly hatched larvae of the original hybrid crosses were similar to those of the maternal line, and the color of the egg yolk was similar to that of the paternal line; therefore, the respective traits of the interspecific parents were identifiable within the cross-bred offspring.