• Title/Summary/Keyword: experimental techniques

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Evaluation on Stress-Strain-Strength Behavior of the Textile Encased Soils via Triaxial Compression Tests (삼축압축시험을 통한 섬유로 구속된 흙의 응력-변형률-강도 거동 평가)

  • Yoo, Wan-Kyu;Kim, Byoung-Il;Cho, Wanjei
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.643-653
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    • 2013
  • Recently, there are an increasing number of studies on the method of wrapping the outer wall of granular piles with geosynthetic fibers such as geotextile or geogrid that has a certain level of tensile strength as an alternative method for the ground improvement techniques. In this study, triaxial compression tests are performed on the sand and clay specimen encased with various textiles to evaluate the reinforcing effect with regard to the tensile strength of the textile. Furthermore, triaxial compression tests are performed on the clay specimen inserted by sand only and sand encased with geosynthetics to compare behavioral differences between the conventional sand compaction pile and geosynthetic encased sand pile with regard to the replacement ratio, ${\alpha}_s$ and the tensile strength of the geosynthetics. Based on the experimental results, the strength enhancement due to the textile is affected by the longitudinal tensile strength rather than the transverse one of the applied textile. The effect of the confinement by the textile encasement results in the large increase of the cohesions. The overall behaviors, such as shear strength, pore pressure parameter at failure and stress ratio, of the geosynthetic encased sand pile is quite different from those of the conventional sand compaction pile.

A Comparative Study on the Theory of Lee jaema and Chang ts' ungcheng (이제마(李濟馬)와 장종정(張從正)의 학술사상(學術思想)에 대한 비교(比較) 연구(硏究))

  • Ch’ oi, yeikwen;Kim, kyungyo
    • Journal of Sasang Constitutional Medicine
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    • v.8 no.2
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    • pp.41-68
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    • 1996
  • This thesis is a try for examining the historical characteristics of Constiutional medicine. For this purpose, I have examined their theory, and made a comparison carefully. Through this study, I have obtained several results as following. Both Chang and Lee lived in the time of change, which was unstable and uncertain. Under the condition, they both rejected following the existing trends of learned circles, and developed new thoughts and clinical techniques. They rejected superstitious beliefs and fatalism, and conducted the pursuit of experimental knowledge and rationale idea. Clinical experience was the very base of their study. They both criticized the bad habits of abuse of tonifing medication and health seeking. Especially Lee regarded control of emotion and regulation of a way of life as the best way for preservation of one's health. Chang regarded pathogenic factors as the ultimate factor of diseases, and strived for eliminating pathogenic factors, but L brought to a conclusion that the final factor of diseases was what is called "heart" itself, and emotional changes were the most essential causes of disease. It can be said that the pathogenesis insisted by Chang can be called The insistence that pathologic factors are the very etiology of all the disease (邪氣致病論), or all the diseases result from pathologic factors. And his whole remedy can be summarized as following, A study on the method of eliminating pathogenic factors. But the purpose of Constitutional medicine is to correct imbalance intrinsic to one's internal organs. In this aspect, Constitutional medicine is a "regulatory medicine". Depending on the classification of six vital substances, Chang classified all disease into six categories. These were based on symptoms and sings represented. While classification of diseases made by Lee was likely to rely upon constitutional characteristics. Chang thought that the three remedies made up of perspiration, purgation, vomiting were the most efficient way of eliminating pathogenic factors. Lee, however, thought those weren't methods of eliminating pathogenic factors but the best ways restoring one's self-regulation power. Chang thought that all the febrile disease essentially has a tendency in properties to belong to "heat", but Lee pointed out that pathologic processes are variable in accordance with constitutional features. They both regarded pathogenesis of diabetes as fire. That is to say, fire is the most essential factor of diabetes. And there are many risk factors such as inappropriate foods, drugs, climate, etc., but Lee thought what is most important is heart. Putting all accounts together, medical characteristics of Chang are similar to those of T aiyinjen and Shaoyangjen, and have no relation to those of those of Shaoyinjen. Therefore we can conclude that Chang understood pathologic processes of disease of T aiyinjen and Shaoyangjen, whether he knew about constitutional features or not.

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Integer Programming-based Local Search Techniques for the Multidimensional Knapsack Problem (다차원 배낭 문제를 위한 정수계획법 기반 지역 탐색 기법)

  • Hwang, Jun-Ha
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.6
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    • pp.13-27
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    • 2012
  • Integer programming-based local search(IPbLS) is a kind of local search based on simple hill-climbing search and adopts integer programming for neighbor generation unlike general local search. According to an existing research [1], IPbLS is known as an effective method for the multidimensional knapsack problem(MKP) which has received wide attention in operations research and artificial intelligence area. However, the existing research has a shortcoming that it verified the superiority of IPbLS targeting only largest-scale problems among MKP test problems in the OR-Library. In this paper, I verify the superiority of IPbLS more objectively by applying it to other problems. In addition, unlike the existing IPbLS that combines simple hill-climbing search and integer programming, I propose methods combining other local search algorithms like hill-climbing search, tabu search, simulated annealing with integer programming. Through the experimental results, I confirmed that IPbLS shows comparable or better performance than the best known heuristic search also for mid or small-scale MKP test problems.

Improvement of Microphone Away Performance in the Low Frequencies Using Modulation Technique (변조 기법을 이용한 마이크로폰 어레이의 저주파 대역 특성 개선)

  • Kim, Gi-Bak;Cho, Nam-Ik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.4 s.304
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    • pp.111-118
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    • 2005
  • In this paper, we employ the modulation technique for improving the characteristics of beamformer in the low frequencies and thus improving the overall noise reduction performance. In the 1-dimensional uniform linear microphone arrays, we can suppress the narrowband noise component using the delay-and-sum beamforming. But, for the wideband noise signal, the delay-and-sum beamformer does not work well for the reduction of low frequency component because the inter-element spacing is usually set to avoid spatial aliasing at high frequencies. Hence, the beamwidth is not uniform with respect to each frequency and it is usually wider at the low frequencies. In order to obtain the beamwidth independent of frequencies, subarray systems[1][2][3][4] and multi-beamforming[5] have been proposed. However these algorithms need large space and more microphones since they are based on the theory that the size of the array is proportional to the wavelength of the input signal. In the proposed beamformer, we reduce the low frequency noise by using modulation technique that does not need additional sensors or non-uniform spacing. More Precisely, the array signals are split into subbands, and the low frequency components are shifted to high frequencies by modulation and reduced by the delay-and-sum beamforming techniques with small size microphone array. Experimental results show that the proposed technique Provides better performance than the conventional ones, especially in the low frequency band.

A Comic Facial Expression Method for Intelligent Avatar Communications in the Internet Cyberspace (인터넷 가상공간에서 지적 아바타 통신을 위한 코믹한 얼굴 표정의 생성법)

  • 이용후;김상운;청목유직
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.1
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    • pp.59-73
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    • 2003
  • As a means of overcoming the linguistic barrier between different languages in the Internet, a new sign-language communication system with CG animation techniques has been developed and proposed. In the system, the joint angles of the arms and the hands corresponding to the gesture as a non-verbal communication tool have been considered. The emotional expression, however, could as play also an important role in communicating each other. Especially, a comic expression is more efficient than real facial expression, and the movements of the cheeks and the jaws are more important AU's than those of the eyebrow, eye, mouth etc. Therefore, in this paper, we designed a 3D emotion editor using 2D model, and we extract AU's (called as PAU, here) which play a principal function in expressing emotions. We also proposed a method of generating the universal emotional expression with Avatar models which have different vertex structures. Here, we employed a method of dynamically adjusting the AU movements according to emotional intensities. The proposed system is implemented with Visual C++ and Open Inventor on windows platforms. Experimental results show a possibility that the system could be used as a non-verbal communication means to overcome the linguistic barrier.

Serum enzymes as indicators of radiation exposure in rat (흰쥐의 방사선 피폭후 생물학적 지표로서의 혈액효소)

  • Kim, In-Gyu;Kim, Sang-Bok;Kim, Jin-Gyu;Kim, Kug-Chan;Chun, Ki-Chung;Park, Hyo-Kook;Lee, Kang-Suk
    • Journal of Radiation Protection and Research
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    • v.18 no.2
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    • pp.37-45
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    • 1993
  • Enzyme activity changes in rat blood as biochemical indicator useful for evaluating exposure dose were experimentally studied. The experimental results obtained are as follows: 1) Alkaline phosphatase activities increased in the blood serum until 24 hours after 0.1, 0.25, 0.5, 2 and 4Gy irradiation and its activities returned normal condition after 72 hours of post-irradiation. Creatine kinase activities increased in the blood serum until 72 hours after 2 and 4Gy irradiation but any significant activity changes were not detected after 0.1, 0.25Gy irradiation. 2) Malate dehydrogenase activities did not reveal available changes after 0.1, 0.25, 0.5 Gy irradiation and lactate dehynrogenase activities decreased in the blood serum after 0.1, 0.25, 0.5 Gy irradiation.3) Glutamate oxaloacetate transaminase activity changes were detected in the blood serum after 0.1, 0.25, 0.5, 2, 4Gy(0.1Gy/min.) and GOT activities increased after 0.5, 1, 1.5, 2, 3, 5, 7Gy(0.5Gy/sec.). Any acid phosphatase activities were detected in the blood serum after 0.1, 0.25, 0.5, 2, 4Gy(0.1Gy/min.) and 0.5, 1, 1.5, 2, 3, 5, 7Gy(0.5 Gy/sec.) irradiation. Potentially some of these enzymes can be used as indicator protein for radiation injury. Futher investigation is needed to find better biochemical indicators utilizing recent know-ledge and techniques of biochemistry.

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Chromosome Analysis in Clinical Samples by Chromosome Diagnostic System Using Fluorescence in Situ Hybridization (국산 Fluorescence in Situ Hybridization 시스템을 이용한 다양한 검체에서의 염색체 분석)

  • Moon, Shin-Yong;Pang, Myung-Geol;Oh, Sun-Kyung;Ryu, Buom-Yong;Hwang, Do-Yeong;Jung, Byeong-Jun;Choe, Jin;Sohn, Cherl;Chang, Jun-Keun;Kim, Jong-Won;Kim, Seok-Hyun;Choi, Young-Min
    • Clinical and Experimental Reproductive Medicine
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    • v.24 no.3
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    • pp.335-340
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    • 1997
  • Fluorescence in situ hybridization (FISH) techniques allow the enumeration of chromosome abnormalities and from a great potential for many clinical applications. In order to produce quantitative and reproducible results, expensive tools such as a cooled CCD camera and a computer software are required. We have developed a Chromosome Image Processing System (Chips) using FISH that allows the detection and mapping of the genetic aberrations. The aim of our study, therefore, is to evaluate the capabilities of our original system using a black-and-white video camera. As a model system, three repetitive DNA probes (D18Z1, DXZ1, and DYZ3) were hybridized to variety different clinical samples such as human metaphase spreads and interphase nuclei obtained from uncultured peripheral blood lymphocytes, uncultured amniocytes, and germ cells. The visualization of the FISH signals was performed using our system for image acquisition and pseudocoloring. FISH images were obtained by combining images from each of probes and DAPI counterstain captured separately. Using our original system, the aberrations of single or multiple chromosomes in a single hybridization experiment using chromosomes and interphase nuclei from a variety of cell types, including lymphocytes, amniocytes, sperm, and biopsied blastomeres, were enabled to evaluate. There were no differences in the image quality in accordance with FISH method, fluorochrome types, or different clinical samples. Always bright signals were detected using our system. Our system also yielded constant results. Our Chips would permit a level of performance of FISH analysis on metaphase chromosomes and interphase nuclei with unparalleled capabilities. Thus, it would be useful for clinical purposes.

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Adverse pregnancy outcomes with assisted reproductive technology in non-obese women with polycystic ovary syndrome: a case-control study

  • Han, Ae-Ra;Kim, Hye-Ok;Cha, Sun-Wha;Park, Chan-Woo;Kim, Jin-Yeong;Yang, Kwang-Moon;Song, In-Ok;Koong, Mi-Kyoung;Kan, Inn-Soo
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.2
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    • pp.103-108
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    • 2011
  • Objective: To investigate adverse pregnancy outcomes in non-obese women with polycystic ovary syndrome (PCOS) compared with obese-PCOS and control groups. Methods: Women with PCOS who underwent assisted reproductive technology (ART) from August, 2003 to December, 2007, were considered. A total of 336 women with PCOS were included in the study group and 1,003 infertile women who had tubal factor as an indication for ART were collected as controls. They were divided into four groups: a non-obese PCOS group, obese-PCOS group, non-obese tubal factor group, and obese tubal factor group, with obesity defined by a body mass index over 25 kg/$m^2$, and reviewed focusing on the basal characteristics, ART outcomes, and adverse pregnancy outcomes. Results: There was no difference among the groups' the clinical pregnancy rate or live birth rate. Regarding adverse pregnancy outcomes, the miscarriage rate, multiple pregnancy rate, and prevalence of preterm delivery and pregnancy induced hypertension were not different among the four groups. The incidence of small for gestational age infant was higher in the PCOS groups than the tubal factor groups ($p$ <0.02). On the other hand, the morbidity of gestational diabetes mellitus (GDM) was not high in the non-obese PCOS group but was in the obese groups. And in the obese PCOS group, the newborns were heavier than in the other groups ($p$ <0.02). Conclusion: Non-obese PCOS presents many differences compared with obese PCOS, not only in the IVF-parameters but also in the morbidity of adverse pregnancy outcomes, especially in GDM and fetal macrosomia.

Development of FURA Code and Application for Load Follow Operation (FURA 코드 개발과 부하 추종 운전에 대한 적용)

  • Park, Young-Seob;Lee, Byong-Whi
    • Nuclear Engineering and Technology
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    • v.20 no.2
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    • pp.88-104
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    • 1988
  • The FUel Rod Analysis(FURA) code is developed using two-dimensional finite element methods for axisymmetric and plane stress analysis of fuel rod. It predicts the thermal and mechanical behavior of fuel rod during normal and load follow operations. To evaluate the exact temperature distribution and the inner gas pressure, the radial deformation of pellet and clad, the fission gas release are considered over the full-length of fuel rod. The thermal element equation is derived using Galerkin's techniques. The displacement element equation is derived using the principle of virtual works. The mechanical analysis can accommodate various components of strain: elastic, plastic, creep and thermal strain as well as strain due to swelling, relocation and densification. The 4-node quadratic isoparametric elements are adopted, and the geometric model is confined to a half-pellet-height region with the assumption that pellet-pellet interaction is symmetrical. The pellet cracking and crack healing, pellet-cladding interaction are modelled. The Newton-Raphson iteration with an implicit algorithm is applied to perform the analysis of non-linear material behavior accurately and stably. The pellet and cladding model has been compared with both analytical solutions and experimental results. The observed and predicted results are in good agreement. The general behavior of fuel rod is calculated by axisymmetric system and the cladding behavior against radial crack is used by plane stress system. The sensitivity of strain aging of PWR fuel cladding tube due to load following is evaluated in terms of linear power, load cycle frequency and amplitude.

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Experimental Study on Characteristics of NOX Reduction with Urea-Selective Catalytic Reduction System in Diesel Passenger Vehicle (승용 디젤차량에서 Urea-SCR 시스템의 NOX 저감 특성에 관한 실험적 연구)

  • Park, Seungwon;Lee, Seangwock;Cho, Yongseok;Kang, Yeonsik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.4
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    • pp.269-275
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    • 2017
  • $NO_X$ reducing technique such as LNT, LNC, and selective catalytic reduction (SCR) have been developed and applied, especially on heavy-duty vehicles. However, it is expected that $NO_X$ reduction techniques will also be applied to diesel passenger vehicles. The urea-SCR system is receiving attention as the most effective $NO_X$ reduction technology without a fuel penalty. Thus, many advanced countries are developing this technology. The urea-SCR system sprays an aqueous urea solution that separates $NO_X$ into $N_2$ and $H_2O$, which are harmless and emitted into the atmosphere. The urea injected in front of the SCR catalyst should be changed to 100% $NH_3$, which is required for $NO_X$ reduction in the SCR system to maximize the reduction efficiency. The purpose of this study was to determine the basic data for the urea-SCR system to maximize the $NO_X$ reduction efficiency by understanding the $NO_X$ reduction characteristics in a real passenger vehicle to comply with the post EURO-6 emission regulation.