• Title/Summary/Keyword: weak limit

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An Analysis of the Internal Deformation Behaviors of Geosynthetic Reinforced Soil Walls used Clayey Soil as Backfills (뒤채움재로 점성토를 사용한 보강토벽의 내적 거동 분석)

  • Kim, Heung-Ki;Kim, You-Seong
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.2
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    • pp.39-49
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    • 2005
  • In this study, the fifteen month behavior of two geosynthetic reinforced walls which was constructed on the shallow weak ground was measured and analyzed. The walls were backfilled with clayey soil obtained from the construction site nearby, and the safety factors obtained from general limit equilibrium analysis were less than 1.3 in both wall. The measured and analyzed data were horizontal earth pressures, strain of reinforcements, and excess pore water pressures. The used reinforcements were nonwoven geotextile, woven geotextile and geogrid. Although the length of reinforcement was only 30% of wall height and the safety factors of the walls were less than 1.3, the walls were constructed without any problems on the such weak ground. The analysis results showed that the maximum strain of reinforcements were negligible and the strain was between 2.3 and 6.0% according to tensile characteristic of the reinforcements. The excess pore water pressure was not changed due to the rainfall and the horizontal earth pressures in upper and lower part of the walls were larger than the active and the rest pressure.

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A Study on the Technical Regulation of Weak Electric Filed Strength Radio Equipment about 8.2Hz Frequency Band (8.2MHz 대역 미약 전계강도 무선기기의 출력기준에 관한 연구)

  • Kim, Sun-Youb;Ra, Yoo-Chan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2498-2504
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    • 2009
  • This paper compared the output limit value of the Korean weak electric field strength wireless device in the 8.2MHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 10-20dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 8.2MHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $70.6dB{\mu}V/m$ and $68.3dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $59.8dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 8.2MHz band.

Effects of the Wire Net Composition on Flexural Properties of Sawdustboard (철강구성(鐵鋼構成)이 톱밥보오드의 휨성질(性質)에 미치는 영향(影響))

  • Lee, Phil-Woo;Suh, Jin-Suk
    • Journal of the Korean Wood Science and Technology
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    • v.13 no.4
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    • pp.67-72
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    • 1985
  • To improve the bending strength of sawdustboard, verious resin contents of 10, 13, 16, and 19% were applied to the thin shell (face layer) composed with wire net or not. The shell effect of sawdust and wire net composition formed with core sawdustboard were evaluated. Forcusing on the effects of wire net composition and noncomposition including a comparison with chipboard and veneer complyboard, bending properties (Modulus of rupture (MOR), Modulus of elasticity (MOE), Stress at proportional limit ($S_{pl}$). Work to maximum load ($W_{ml}$))were analyzed and discussed. 1. In modulus of rutpute, veneer comply was the highest (621.5 kg/$cm^2$), and next decreasing order was wire net composition (159.1 kg/$cm^2$), chipboard (81.75 kg/$cm^2$), and wire net noncomposition (76.21 kg/$cm^2$) as in modulus of elasticity, work to maximum load, except for stress at proportional limit. 2. The highly significant effects were shown in both wire net composition and noncomposition, at the same time wire net composition exceeded two times of noncomposition throughout resin contents in bending properties. Chipboard was similar to the mean or 16% resin content in noncomposirion. 3. Every board in wire net composition above 10% resin content was beyond 100 kg/$cm^2$ in MOR, minimum allowable strength for structural use according to KS F 3104. In conclusion, the feasibility for improving the bending strength of weak sawdustboard by wire net composed shell was offered.

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Design of umbrella arch method based on adaptive SVM and reliability concept (Adaptive SVM 기법 및 신뢰성 개념을 적용한 강관다단공법의 설계기법 연구)

  • Lee, Jun S.;Sagong, Myung;Park, Jeongjun;Choi, Il Yoon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.4
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    • pp.701-715
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    • 2018
  • A reliability based design approach of the tunnel reinforcement with umbrella arch method was considered to better represent the uncertainties of the weak rock properties around the tunnel. For this, a machine learning approach called an Adaptive Support Vector Machine (ASVM) together with the limit equilibrium method were introduced to minimize the iteration numbers during the classification training of the tunnel stability. The proposed method was compared with the results of typical Monte Carlo simulations. It was concluded that the ASVM was very efficient and accurate to calculate the probability of failure having auxiliary umbrella arches and uncertain material properties of the tunnel. Future work will be concentrated on the refinement of the fast adaptation of the SVM classification so that the minimum number of numerical analyses can be used where the limit solution is not available.

Value Chain Model and Big Data Utilization for a Successful the 6th Industry (성공적인 6차산업을 위한 가치사슬 모형과 빅데이터 활용 방안)

  • Park, Sanghyeok;Park, Jeongseon;Lee, Myounggwan
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.11 no.2
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    • pp.141-152
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    • 2015
  • Our agriculture and rural villages have faced negative conditions in many reasons. To overcome this situation, a new change is needed by the 6th industrialization. Many agriculture and rural villages in Korea are pursuing the 6th industrialization through the convergence of the primary, secondary, and tertiary industries to vitalize agriculture and rural villages. But there are several problems with the 6th industrialization. There is a limit to the capacity building of the members of the rural organization and Korean agricultural base primary, secondary, and tertiary industries are weak all. In addition, it has been insufficient research for value chain management of the region as a whole; there has been no study of information sharing across the region for the 6th industrialization. This study is about value chain management model for successful the 6th industry with Quick Response System and the big data technology. In this study to provide the efficiency of 6th industry value chain management with customer's needs analysis using big data and research for the information share between the industries in the region through the information pipeline theory of the QR System. We hope that our study is helped to proceed successfully on the 6th industrialization in Korea.

Barriers on Development of Clinical Practice Guidelines for Cardiopulmonary Resuscitation (임상진료지침 개발과정의 장애요인 - 심폐소생술을 중심으로 -)

  • Park, Seong-Hi
    • Quality Improvement in Health Care
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    • v.7 no.1
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    • pp.46-58
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    • 2000
  • Background : Despite favorable effects of guidelines on patient care, guidelines often fail to achieve their objectives. Poorly implemented medical practice guidelines can produce only weak effects on the process of health care delivery. Therefore, we performed this study to investigate barriers related development of clinical practice guidelines. Methods : Cardiopulmonary resuscitation was selected as a target problem. Self questionnaires about management of cardiopulmonary resuscitation were developed by a researcher with advisory 8 experts. The questionnaires were designed as a unstructured methods. The data were collected from March 1 to May 31, 1999. A total 50 death case admitted inpatient to Inha University Hospital were subjected to evaluate the development and application of clinical practice guidelines for cardiopulmonary resuscitation. The data were examined by frequency, t-test with SPSS. Result : The article reviewed several common barriers that might limit successful implementation of guidelines in clinical practice, as illustrated by evaluating recommendations for cardiopulmonary resuscitation clinical practice guidelines. Some major problems with guidelines were characterized as follows (1) ethical problem : euthanasia, (2) occurrence on various emergency event and setting, (3) non-medical problems (4) unreliable of medical record etc. Conclusion : Careful analysis of guideline attributes, anticipated effect on medical care, and organizational factors revealed several barriers to successful guideline implementation that should be addressed in the design of future guideline-based interventions.

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Cycle Analysis of Hot Water Driven Absorption Refrigerator with New Working Absorption Solution (신흡수용액을 이용한 중온수 흡수식 냉동기의 사이클 해석)

  • Gwon, O-Gyeong;Yun, Jae-Ho;Mun, Chun-Geun;Yun, Jeong-In
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.9
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    • pp.1241-1248
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    • 2002
  • Performance extension of the absorption refrigerator with LiBr solution is often faced to operate very close to the crystallization limit. Especially in the development of an air-cooled cycle, the crystallization of working solution in the system is a very difficult problem to overcome. This paper describes the cycle of hot water driven absorption system using a new working absorption solution instead of LiBr solution to improve the efficiency. In this study, we found out the characteristics of new working absorption solution through the cycle simulation and compared LiBr solution to evaluate. The effect of cooling water temperature, weak solution flow rate, hot water temperature and hot water flow rate were also examined. The COP is increased 22% higher in the case of LiBr+Li1+LiC1+LiNO$_3$$H_2O$, 2% LiBr+HO(CH$_2$)$_3$OH+$H_2O$ than that of LiBr solution for the same operation condition.

Voltammetric Behavior and Determination of Rubeanic acid at Mercury (수은 전극에서 루비안산의 전압-전류 거동 및 정량)

  • Kwon, Young-Soon;Koo, Hee-Jin
    • Analytical Science and Technology
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    • v.10 no.3
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    • pp.216-224
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    • 1997
  • In the study of cyclic voltammogram of rubeanic acid, rubeanic acid has two reduction peaks; first peak is similar with that of $S^{2-}$ and thiourea, which is conceded to by HgS, second peak is very weak and unidentified. The study also describes the differential pulse cathodic stripping voltammetric method for the determination of rubeanic acid. The followings were optimal conditions of rubeanic acid for the study : 0.05M borate buffer solution(pH 10.0) ; an accumulation potential of -0.30V(vs. Ag/AgCl); accumulation time of 120sec. : scan rate of 10mV/sec. The detection limit of trace analysis shows $2.7{\times}10^{-8}M$ of rubeanic and at optimal conditions.

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A Image Feedback control of Mobile Robot for Target Tracking (모바일 로봇의 목표물 추적을 위한 이미지 궤환 제어)

  • Hwang, Won-Jun;Lee, Woo-Song
    • Journal of the Korean Society of Industry Convergence
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    • v.18 no.2
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    • pp.90-98
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    • 2015
  • This research propose with image-based visual a new approach to design a feedback control of mobile robot. because mobile robot must be recharged periodically, it is necessary to detect and move to docking station. Generally, laser scanner is used for detect of position of docking station. CCD Camera is also used for this purpose. In case of using camera, the position-based visual servoing method is widely used. But position-based visual servoing method requires the accurate calibration and it is hard and complex work. Another method using cameras is inmage-based visual feedback. Recently, image based visual feedback is widely used for robotic application. But it has a problem that cannot have linear trajectory in the 3-dimensional space. Because of this weak point, image-based visual servoing has a limit for real application. in case of 2-dimensional movement on the plane, it has also similar problem. In order to solve this problem, we point out the main reason of the problem of the resolved rate control method that has been generally used in the image-based visual servoing and we propose an image-based visual feedback method that can reduce the curved trajectory of mobile robot in th cartesian space.

A Study on Using Method of Analogy for Creativity Enhancement(1) - Experimental Study Focused on the Design Task of Commercial Space - (창의성 증진을 위한 유추의 활용방법(1) - 상업공간 디자인과제를 중심으로 한 실험연구 -)

  • Choi, Eun-Hee
    • Korean Institute of Interior Design Journal
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    • v.19 no.4
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    • pp.31-38
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    • 2010
  • The objective of this study is to find a educational method that is able to increase creativity using both left and right directed thinking with complementary cooperation. The premise of experimental study is that analogical inference is a great help to make a creative design, and design tasks of commercial space, fashion shop and herb cafe are given to 25 students, voluntary participants in experimental tests. Tests make a clear distinction between a case using verbal analogy from many keywords and another case using verbal visual analogy from keywords and visual images. Consequently, when students use both verbal and visual analogy in solving design tasks their creative ability qualitatively as well as quantitatively is higher than in using verbal analogy. However, when students are classified with high and low sketching group verbal visual analogy is effective for students with high sketching ability to enhance both practicality and originality. Even students with low sketching ability can improve originality remarkably by using verbal visual analogy. In experiment there is time limit, a hour, but in actual studio class it is desirable that an educator guides the latter to make up for the weak points in practicality of their design taking time. Further study will be progressed with the design tasks of residential space to compare with the findings of this study.