• Title/Summary/Keyword: Static and Dynamic Analysis

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Effect of Constrain Condition of Soil Nail Head on Slope Stability (쏘일 네일 두부 구속조건이 사면 안정성에 미치는 영향)

  • Kim, Yongeung;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.2
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    • pp.37-43
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    • 2014
  • Natural disasters such as earthquakes and tsunamis occur suddenly, so that they cause massive loss of lives and property. Especially earthquakes represent a particularly severe threat because of the extensive damage accompanied by them. In Korea, an earthquake-resistant design has been rarely applied to a design or construction of slope. However, in resent years, the researches for earthquake-resistance have been performed because the importance on the earthquake-resistance is perceived and highlighted. Soil nail method, one of the slope stability methods, is excellent for its constructability and cost effectiveness, as compared with other stability methods. Also, this method has been widely used for reinforced construction for slope stability. The studies of soil nail method have been performed on the interaction behavior between nails and slopes as well as the varied load condition such as static load, dynamic load and so on. Nevertheless, there has been minimal research regarding the constraint condition of nail head. In this study, the numerical analysis was performed for identifying effect on slope stability for the constrain condition of the soil nail. The result shows that the resistance of constrained the nail head on reinforced slope is larger compared to the one of unconstrained nail head.

A Study of Accelerator Investment Determinants Based on Business Model Innovation Framework (비즈니스 모델 혁신 프레임워크 기반의 액셀러레이터 투자결정요인 연구)

  • Jung, Mun-Su;Kim, Eun-Hee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.2
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    • pp.65-80
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    • 2022
  • Despite the uncertainty and risky factors of startups, the special and critical role of accelerators in carrying out professional nurturing and investment for them is becoming increasingly significant in the startup social-system. However, academic research on investment determinants that have a profound impact on the survival of accelerators is lacking, and there are only a few empirical studies on the classification and importance of factors, and they do not enjoy the benefits of theoretical studies. This study proposes a business model innovation framework based on the business model innovation theory that reflects the nature and properties of startups that are investment targets of accelerators and derives 12 investment decision factors. The framework defines that the target, direction, and performable force of startup innovation are a business model, strategy, and dynamic capability. Besides, the framework analyzes the investment decision factors of the existing accelerators based on the business model innovation framework to verify the suitability and sufficiency of the composition. As a result of the analysis, first, most of the items were faithfully composed from a static point of view of business model innovation, but it was found that the factors related to the core activities to evaluate the activity and customer relationship were insufficient. Second, from the strategic point of view, the necessity of developing factors that can encompass the definition and content of core resources, which are internal strategic factors, was raised. Third, from the dynamic point of view, it was found that many of the investment determinants of accelerators were concentrated on the lower level of dynamic competencies. This can be judged as a result of reflecting the characteristics of a startup that needs to develop a solution with few resources and a small number of team members. In addition, the roles and interrelationships between each factor are not clear, thus it was found as a limiting point for startups to view and evaluate the direction and process in which startups dynamically innovate their business models. This study is considerably differentiated in that it provides a business model innovation framework and offers a theoretical basis for investment determinants by deriving the investment determinants of accelerators based on the framework and design the foundation for subsequent research. The business model innovation framework presented in this study has great implications in that it contributes to the achievement of startups, accelerators, and startup support organizations.

Correlation between Semiquantitative Myocardial Perfusion Score and Absolute Myocardial Blood Flow in $^{13}N-Ammonia$ PET ($^{13}N$-암모니아 PET에서 반정량적 심근관류 점수와 절대적 심근혈류량의 상관관계)

  • Lee, Byeong-Il;Kim, Kye-Hun;Kim, Jung-Young;Kim, Su-Jin;Lee, Jae-Sung;Min, Jung-Joon;Song, Ho-Chun;Bom, Hee-Seung
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.3
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    • pp.194-200
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    • 2007
  • Purpose: $^{13}N$-ammonia is a well known radiopharmaceutical for the measurement of a myocardial blood flow (MBF) non-invasively using PET-CT. In this study, we investigated a correlation between MBF obtained from dynamic imaging and myocardial perfusion score (MPS) obtained from static imaging for usefulness of cardiac PET study. Methods: Twelve patients (11 males, 1 female, $57.9{\pm}8.6$ years old) with suspicious coronary artery disease underwent PET-CT scan. Dynamic scans (6 min: $5\;sec\;{\times}\;12,\;10\;sec\;{\times}\;6,\;20\;sec\;{\times}\;3,\;and\;30\;sec\;{\times}\;6$) were initiated simultaneously with bolus injection of 11 MBq/kg $^{13}N-ammonia$ to acquire rest and stress image. Gating image was acquired during 13 minutes continuously. Nine-segment model (4 basal walls, 4 mid walls, and apex) was used for a measurement of MBF. Time activity curve of input function and myocardium was extracted from ROI methods in 9 regions for quantification. The MPS were evaluated using quantitative analysis software. To compare between 20-segment model and 9-segment model, 6 basal segments were excluded and averaged segmental scores were used. Results: There are weak correlation between MBF (rest, 0.18-2.38 ml/min/g; stress, 0.40-4.95 ml/min/g) and MPS (rest 22-91%, stress, 14-90%), however the correlation coefficient between corrected MBF and MPS in rest state was higher than stress state (rest r=0.59; stress r=0.80). As a thickening increased, correlation between MBF and MPS also showed good correlation at each segments. Conclusions: Corrected and translated MPS as its characteristics using $^{13}N$-ammonia showed good correlation with absolute MBF measured by dynamic image in this study. Therefore, we showed MPS is one of good indices which reflect MBF. We anticipate PET-CT could be used as useful tool for evaluation of myocardial function in nuclear cardiac study.

Evaluation of Road and Traffic Information Use Efficiency on Changes in LDM-based Electronic Horizon through Microscopic Simulation Model (미시적 교통 시뮬레이션을 활용한 LDM 기반 도로·교통정보 활성화 구간 변화에 따른 정보 이용 효율성 평가)

  • Kim, Hoe Kyoung;Chung, Younshik;Park, Jaehyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.2
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    • pp.231-238
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    • 2023
  • Since there is a limit to the physically visible horizon that sensors for autonomous driving can perceive, complementary utilization of digital map data such as a Local Dynamic Map (LDM) along the probable route of an Autonomous Vehicle (AV) is proposed for safe and efficient driving. Although the amount of digital map data may be insignificant compared to the amount of information collected from the sensors of an AV, efficient management of map data is inevitable for the efficient information processing of AVs. The objective of this study is to analyze the efficiency of information use and information processing time of AV according to the expansion of the active section of LDM-based static road and traffic information. To carry out this objective, a microscopic simulator model, VISSIM and VISSIM COM, was employed, and an area of about 9 km × 13 km was selected in the Busan Metropolitan Area, which includes heterogeneous traffic flows (i.e., uninterrupted and interrupted flows) as well as various road geometries. In addition, the LDM information used in AVs refers to the real high-definition map (HDM) built on the basis of ISO 22726-1. As a result of the analysis, as the electronic horizon area increases, while short links are intensively recognized on interrupted urban roads and the sum of link lengths increases as well, the number of recognized links is relatively small on uninterrupted traffic road but the sum of link lengths is large due to a small number of long links. Therefore, this study showed that an efficient range of electronic horizon for HDM data collection, processing, and management are set as 600 m on interrupted urban roads considering the 12 links corresponding to three downstream intersections and 700 m on uninterrupted traffic road associated with the 10 km sum of link lengths, respectively.

A Study on Beverage Consumption Pattern and Image of College Students (대학생들의 음료 소비실태 및 이미지 조사 연구)

  • 박모라
    • Journal of the East Asian Society of Dietary Life
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    • v.9 no.4
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    • pp.501-513
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    • 1999
  • In order to investigate consumption pattern and image of beverage, this study was performed by using questionnaire based on stratified random sampling about 200 students from September 6, 1999 to September 18, 1999. The result was as followings: 1. For the reasons of each beverage consumption, coke, soda pop and sport drinks were for quenching thirst. And coffee and juices were for dessert and milk.yoghurts, dietary beverages, green tea and ginseng tea were for health. 2. For the priority in selecting each beverage, trademark was dominant factor for choosing coke. And the dominant factor of choosing milk.yoghurts and ginseng tea was nutrition and in case of other beverages taste was the first factor. 3. For the place of taking beverages, coffee, coke and sport drinks were mainly consumed in school and milk.yoghurt and juices in home. 4. The college students loved or liked milk.yoghurt and juices, and they liked or enjoyed coke, soda pop, sport drinks and green tea moderately, and enjoyed ginseng tea and black tea moderately or disliked them. 5. For the frequency of each beverage, many of them consumed coffee and milk.yoghurt once or twice a day. and consumed coke. soda pop. sport drinks and juices once or twice a week. And they answered that they did not consume dietary beverages, green tea, ginseng tea and black tea so often. 6. There was significant correlation with frequency of drinking and preference score of beverage. 7. For the consumption of the Korean traditional beverages, more than 50% of the subjects had no experience in taking sangwha tea, omiza tea, and Kugiza tea. Among them, many answered that they would try the Korean traditional beverages, if they had an opportunity, and that their price was moderate. 8. The results from the analysis of the image of those beverages were as followings; \circled1 Coffee, coke, sport drinks and dietary beverages had a modern image and green tea, ginseng tea and black tea had a traditional image. \circled2 Coke, sport drinks and ginseng tea had a manly image and juices, dietary beverages, green tea and black tea had a womanlike image. \circled3 The students recognized coffee, coke, milkㆍyoghurt, sport drinks, juices, dietary beverages and green tea to be daily and catholic. \circled4 Milkㆍyoghurt, juices, dietary beverages, green tea, ginseng tea and black tea were recognized to be good for health and coffee and coke bad for health. \circled5 Coffee, coke, soda pop, sport drinks, juices and green tea were slightly concerned with a change. \circled6 Coke, soda pop and sport drinks had a dynamic image and coffee, juices. green tea, ginseng tea and black tea had a little static image.

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On the "Virtual and Real" and Blankness in Chinese Landscape Painting

  • Dongqi, Liu
    • International Journal of Advanced Culture Technology
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    • v.10 no.3
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    • pp.174-183
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    • 2022
  • The abstract should summarize the contents of the paper and written below the author information. Use the word "Abstract" as the title, in 12-point Times New Roman, boldface type, italicized, centered relative to the column, initially capitalized, fixed-spacing at 13 pt., 12 pt. spacing before the text and 6 pt. after. The abstract content is to be in 11-point, italicized, single spaced type. Leave one blank line after the abstract, and then begin the keywords. All manuscripts must be in English. When it comes to the issue of "virtual and real" in traditional Chinese painting, the first impression is to describe the problems of painting strokes and ink, layout of pictures, etc., but it runs through the initial conception of the work, creation in the middle and aesthetic appreciation of the work. It exists in the whole process of artistic creation and appreciation. In essence, it is a problem of aesthetic thinking and philosophical thinking. Because the traditional Chinese painting theory is influenced by Taoism, when the concept of "virtual and real" is implemented in the specific picture of Chinese painting, it is contained in the specific shape of "physics", that is, the painting theory research of "blank space" in the picture. Based on the traditional Taoist philosophy of China, this paper takes the "virtual and real" view in Lao Zhuang's thought as the research object, deeply analyzes and compares its relationship with the "virtual and real" in Chinese landscape painting, and finds out their artistic spirit, essential characteristics and how to present them. This paper mainly discusses the internal relationship between Taoist philosophy and "virtual and real" in Chinese landscape painting from the following aspects. The introduction expounds the origin, purpose, significance, innovation and research methods of the topic. This paper analyzes the philosophical thoughts about landscape in the philosophical thoughts represented by Lao Tzu and Zhuangzi. The development of Chinese traditional aesthetics theory is closely related to Taoist philosophy, which has laid the foundation and pointed out the direction for the development of Chinese painting theory since ancient times. It also discusses the influence of the Taoist philosophy of "the combination of the virtual and real" on the emergence and development of the artistic conception of landscape painting. Firstly, through the analysis of the artistic conception of landscape painting and its constituent factors, it is pointed out that the artistic conception is affected by the personality and the painting artistic conception. Secondly, through the Taoist thought of "the combination of the virtual and real" in landscape painting, so as to reflect that it is the source of the artistic conception of Chinese landscape painting. It is the unique spiritual concept of "Yin and Yang" and "virtual and real" that creates the unique "blank space" aesthetic realm of Chinese painting in the composition of the picture. Finally, it focuses on the "nothingness" in Taoist philosophy and the "blank space" in Chinese landscape painting. The connotation of the "blank space" in Chinese painting exceeds its own expressive significance, which makes the picture form the aesthetic principle of emotional blending, virtual and real combination and dynamic and static integration. Through the "blank space", it deepens the artistic characteristics of the picture and sublimates the expression of "form" in Chinese painting.

Effects of Eucommiae Cortex (杜冲) on the Bone Histomorphometry and Metabolism in Ovariectomized Rats (두충(杜冲)이 난소적출(卵巢摘出) 흰쥐의 골조직(骨組織) 형태(形態)와 골대사(骨代謝)에 미치는 영향(影響))

  • Yang, Sung-Woo;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
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    • v.18 no.1
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    • pp.128-141
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    • 2005
  • Objective : This study was undertaken to investigate the effects of Eucommiae Cortex on the osteoporosis in ovariectomized rats. Materials and Methods : We used Sprague-Dawley female rats in 8-week-old. They were divided into three groups. Sample group was ovariectomized and administered with 10 mg/100 g/day Eucommiae Cortex extract solution for 10 weeks. Control group was ovariectomized and sham group was conducted by sham's operation. And control group and sham group were administered with normal saline as the same way. We measured rats's body and uterus weight and also measured the serum levels of Ca, phosphorus and ALP. We stained the specimens of rat's tibial bones with Goldner's modified Masson's Trichrome and then examined bone histomorphometry with Bioquant computer program of image analysis system. We measured the thickness of osteoid and callus as static parameters and measured bone volume and mineral apposition rate as dynamic parameters. We observed the expressions of RANKL and OPG mRNA of the tibial bone by RT-PCR. Results : The body weight was significantly (p<0.05) increased in control and sample groups compared with sham group, respectively. The uterus weight was significantly (p<0.05) decreased in control and sample group compared with sham group. In the change of Ca, phosphorus and ALP there were no significant changes among three groups. There were no significant changes of trabecula cortical and osteoid bones' thickness and volume. But trabecula mineral apposition rate (MAR) was significantly (p<0.05) increased in sham and sample group compared with control group. In the expression of RANKL mRNA, sample group was decreased compared with control group, and in that of OPG mRNA, sample group was increased compared with control group. Conclusion : This study shows that Eucommiae Cortex has the beneficial effects on bone histomorphometry and metabolism in the ovariectomized rats. We suggest that Eucommiae Cortex be useful for the treatment of osteoporosis.

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Seismic behavior of K-type eccentrically braced frames with high strength steel based on PBSD method

  • Li, Shen;Wang, Chao-yu;Li, Xiao-lei;Jian, Zheng;Tian, Jian-bo
    • Earthquakes and Structures
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    • v.15 no.6
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    • pp.667-685
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    • 2018
  • In eccentrically braced steel frames (EBFs), the links are fuse members which enter inelastic phase before other structure members and dissipate the seismic energy. Based on the force-based seismic design method, damages and plastic deformations are limited to the links, and the main structure members are required tremendous sizes to ensure elastic with limited or no damage. Force-based seismic design method is very common and is found in most design codes, it is unable to determine the inelastic response of the structure and the damages of the members. Nowadays, methods of seismic design are emphasizing more on performance-based seismic design concept to have a more realistic assessment of the inelastic response of the structure. Links use ordinary steel Q345 (the nominal yielding strength $f_y{\geq}345MPa$) while other members use high strength steel (Q460 $f_y{\geq}460MPa$ or Q690 $f_y{\geq}690MPa$) in eccentrically braced frames with high strength steel combination (HSS-EBFs). The application of high strength steels brings out many advantages, including higher safety ensured by higher strength in elastic state, better economy which results from the smaller member size and structural weight as well as the corresponding welding work, and most importantly, the application of high strength steel in seismic fortification zone, which is helpful to popularize the extensive use of high strength steel. In order to comparison seismic behavior between HSS-EBFs and ordinary EBFs, on the basis of experimental study, four structures with 5, 10, 15 and 20 stories were designed by PBSD method for HSS-EBFs and ordinary EBFs. Nonlinear static and dynamic analysis is applied to all designs. The loading capacity, lateral stiffness, ductility and story drifts and failure mode under rare earthquake of the designs are compared. Analyses results indicated that HSS-EBFs have similar loading capacity with ordinary EBFs while the lateral stiffness and ductility of HSS-EBFs is lower than that of EBFs. HSS-EBFs and ordinary EBFs designed by PBSD method have the similar failure mode and story drift distribution under rare earthquake, the steel weight of HSS-EBFs is 10%-15% lower than ordinary EBFs resulting in good economic efficiency.

Level Shifts and Long-term Memory in Stock Distribution Markets (주식유통시장의 층위이동과 장기기억과정)

  • Chung, Jin-Taek
    • Journal of Distribution Science
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    • v.14 no.1
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    • pp.93-102
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    • 2016
  • Purpose - The purpose of paper is studying the static and dynamic side for long-term memory storage properties, and increase the explanatory power regarding the long-term memory process by looking at the long-term storage attributes, Korea Composite Stock Price Index. The reason for the use of GPH statistic is to derive the modified statistic Korea's stock market, and to research a process of long-term memory. Research design, data, and methodology - Level shifts were subjected to be an empirical analysis by applying the GPH method. It has been modified by taking into account the daily log return of the Korea Composite Stock Price Index a. The Data, used for the stock market to analyze whether deciding the action by the long-term memory process, yield daily stock price index of the Korea Composite Stock Price Index and the rate of return a log. The studies were proceeded with long-term memory and long-term semiparametric method in deriving the long-term memory estimators. Chapter 2 examines the leading research, and Chapter 3 describes the long-term memory processes and estimation methods. GPH statistics induced modifications of statistics and discussed Whittle statistic. Chapter 4 used Korea Composite Stock Price Index to estimate the long-term memory process parameters. Chapter 6 presents the conclusions and implications. Results - If the price of the time series is generated by the abnormal process, it may be located in long-term memory by a time series. However, test results by price fixed GPH method is not followed by long-term memory process or fractional differential process. In the case of the time-series level shift, the present test method for a long-term memory processes has a considerable amount of bias, and there exists a structural change in the stock distribution market. This structural change has implications in level shift. Stratum level shift assays are not considered as shifted strata. They exist distinctly in the stock secondary market as bias, and are presented in the test statistic of non-long-term memory process. It also generates an error as a long-term memory that could lead to false results. Conclusions - Changes in long-term memory characteristics associated with level shift present the following two suggestions. One, if any impact outside is flowed for a long period of time, we can know that the long-term memory processes have characteristic of the average return gradually. When the investor makes an investment, the same reasoning applies to him in the light of the characteristics of the long-term memory. It is suggested that when investors make decisions on investment, it is necessary to consider the characters of the long-term storage in reference with causing investors to increase the uncertainty and potential. The other one is the thing which must be considered variously according to time-series. The research for price-earnings ratio and investment risk should be composed of the long-term memory characters, and it would have more predictability.

CHARACTERIZATION OF GEOTECHNICAL SITES BY MULTI-CHANNEL ANALSIS OF SURFACE WAVES(MCASW) (지표층의 탄성계수 측정을 위한 새로운 탄성파 방법)

  • 박춘병
    • Proceedings of the Korean Geotechical Society Conference
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    • 1995.10a
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    • pp.15.2-22
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    • 1995
  • Evaluating stiffness of near-surface materials has been one of the critically important tasks in many civil engineering works. It is the main goal of geotechnical characterization. The so-called deflection-response method evaluates the stiffness by measuring stress-strain behavior of the materials caused by static or dynamic load. This method, however, evaluates the overall stiffness and the stiffness variation with depth cannot be obtained. Furthermore, evaluation of a large-area geotechnical site by this method can be time-consuming, expensive, and damaging to many surface points of the site. Wave-propagation method, on the other hand, measures seismic velocities at different depths and stiffness profile (stiffness change with depth) can be obtained from the measured velocity data. The stiffness profile is often expressed by shear-wave (S-wave) velocity change with depth because S-wave velocity is proportional to the shear modulus. that is a direct indicator of stiffiiess. The crosshole and downhole method measures the seismic velocity by placing sources and receivers (geophones) at different depths in a borehole. Requirement of borehole installation makes this method also time-consuming, expensive, and damaging to the sites. Spectral-Analysis-of-Surface-Waves (SASW) method places both source and receivers at the surface, and records horizontally-propagating surface waves. Based upon the theory of surfacewave dispersion, the seismic velocities at different depths are calculated by analyzing the recorded surface-wave data. This method can be nondestructive to the sites. However, because only two receivers are used, the method requires multiple measurements with different field setups and, therefore, the method often becomes time-consuming and labor-intensive. Furthermore. the inclusion of noise wavefields cannot be handled properly, and this may cause the results by this method inaccurate. When multi-channel recording method is employed during the measurement of surface-waves, there are several benefits. First, usually single measurement is enough because multiple number (twelve or more) of receivers are used. Second, noise inclusion can be detected by coherency checking on the multi-channel data and handled properly so that it does not decrease the accuracy of the result. Third, various kinds of multi-channel processing techniques can be applied to f1lter unwanted noise wavefields and also to analyze the surface-wavefields more accurately and efficiently. In this way, the accuracy of the result by the method can be significantly improved. Fourth, the entire system of source, receivers, and recording-processing device can be tied into one unit, and the unit can be pulled by a small vehicle, making the survey speed very fast. In all these senses, multi-channel recording of surface waves is best suited for a routine method for geotechnical characterization in most of civil engineering works.

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