• Title/Summary/Keyword: External problems

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Problems and Prospects of Tobacco Quality Evaluation (잎담배 품질평가방법의 문제점 및 전망)

  • Lee, Seung-Chul;Ryu, Myung-Hyun;Han, Chul-Soo;Ban, Yu-Son
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.s01
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    • pp.124-138
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    • 1988
  • This paper comprised a review of published literature dealing with the evaluation of tobacco quality and usability. Evaluation of tobacco quality and usability seems to be difficult not only due to our inability to define them in simple and easily measurable term but also due to their relations to the profitability of tobacco companies and safety of comsumers. Chemical constituents and smoking taste and aroma of the tobacco represent the underlying basis for tobacco quality: however, tobacco is still purchased upon its physical appearance. Grade and value system is very convenient for evaluating the tobacco quality, if the system is based on the triangular relationship of physical appearance, chemical and smoking properties of tobacco, and also based on intrinsic quality of the tobacco independent of external influences. Grade and value system for tobacco in Korea is thought to be influenced by external factors besides intrinsic quality. Therefore, we have to concern new systems that could be supplement to, or replacement for currently available grade and value system.

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An Experimental Study on the Estimation Flow-rate of Venturi Pump Using LightGBM (LightGBM을 이용한 수력 펌프 유량 추정의 실험적 연구)

  • Jin Beom Jeong;Jihwan Lee;Myeongcheol Kang
    • Journal of Drive and Control
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    • v.20 no.4
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    • pp.123-132
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    • 2023
  • In disaster situations, to facilitate rapid drainage, electric underwater pumps are installed manually. This poses a high risk of electric shock accidents due to a short circuit, and a lot of time is required for hose connection and installation of electrical devices. To solve these problems, a Venturi pump using the venturi effect without external power is used. However, Venturi pumps that operate without external power make it difficult to install flow sensors such as electric devices; consequently, it is difficult to check the real-time flow rate. This paper proposes a flow estimation logic to replace the function of the flow sensor for the venturi pump . To develop the flow estimation logic, the flow characteristics of the venturi pump, according to the operating conditions, were checked. After that, the relationship with the flow rate of the venturi pump was defined using a pressure sensor corresponding to a low-cost sensor. Finally, an analysis of the estimation error was performed using the developed flow estimation logic.

Flexural Capacity of Reinforced Concrete Beams Strengthened by Bow System (Bow 공법으로 보강된 철근콘크리트 보의 휨보강 성능)

  • Lim, Jae-Hyung;Moon, Jeong-Ho;Lee, Jae-Yeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.3 s.55
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    • pp.181-187
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    • 2009
  • This paper is to investigate about a new technique (Bow system) which is to develop the disadvantages of the external post-tensioned method. The purpose of this paper is to analyze about the prestress loss when the loads apply along the long term and to improve the capacity of the members strengthened by Bow system. The variables in the test program are the span/depth ratio, the amount of tendon area. And the test was carried out to confirm the long term behaviour. It is shown that can apply the current code in the design, and have no the structural problems about the prestress loss.

Improvement of Active Contour Model for Detection of Pulmonary Region in Medical Image (의학 영상에서 폐 영역 검출을 위한 Active Contour 모델 개선)

  • Kwon Y. J.;Won C. H.;Park H. J.;Lee J. H.;Lee S. H.;Cho J. H.
    • Journal of Korea Multimedia Society
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    • v.8 no.3
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    • pp.336-344
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    • 2005
  • In this paper, we extracted the contour of lung parenchyma on EBT images with the improved active contour model. The objects boundary in conventional active contour model can be extracted by controlling internal energy and external energy as energy minimizing form. However, there are a number of problems such as initialization and the poor convergence about concave part. Expecially, contour can not enter the concave region by discouraging characteristic about stretching and bending in internal energy. We controlled internal energy by moving local perpendicular bisector point of each control point in the contour and implemented the object boundary by minimizing energy with external energy The convergence of concave part could be efficiently implemented toward lung parenchyma region by this internal energy and both lung images for initial contour could also be detected by multi-detection method. We were sure this method could be applied detection of lung parenchyma region in medical image.

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Effect of Added Mass between Male and Female on The Lower Extremity Joints Angular Velocity, Moment, Absorb Energy During Drop Landing (착지 시 외부 무게 부하에 따른 남성과 여성의 하지 관절 각속도, 모멘트, 에너지 흡수에 미치는 영향)

  • Kwon, Moon-Seok
    • Korean Journal of Applied Biomechanics
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    • v.22 no.3
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    • pp.325-332
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    • 2012
  • This study aimed to analyze the effects of external load between male and female on angular velocity, moment, and absorbed energy of the lower-extremity joints during drop landing. The study subjects were 9 male($mass=70.82{\pm}4.64kg$, $height=1.71{\pm}0.04m$, $age=24.5{\pm}1.84years$), 9 female($mass=50.14{\pm}4.09kg$, $height=1.61{\pm}0.03m$, $age=23.6{\pm}2.62years$), without any serious musculoskeletal, coordination, balance, or joint/ligament problems for 1 year before the study. The angular velocity, flexion/extension and abduction/adduction moments, and absorbed energy of the lower-extremity joints were compared between the men and women during drop landing under 4 different conditions of external load(0%, 8%, 16%, and 24%) by using two-way repeated ANOVA(p < .05). The women landed with a greater peak angular velocity of the ankle joint, greater peak inversion moment, and lower peak hip-extension moment than the men did, under all 4 conditions. Additionally, the landing characteristics of the women were distinct from those of the men; the women showed a greater peak knee-adduction moment and greater absorbed energy of the knee joint. These differences indicate that anterior cruciate ligament(ACL) strain was greater in the women than in the men and therefore, women may be at a higher potential risk for noncontact injuries of the ACL with an increase in external load.

Prevention of Cheek Drooping in Intraoral Reduction Malarplasty without Internal Fixation (볼처짐 최소화를 위한 최소절개 및 박리 관골 축소 성형술)

  • Park, Dong-Kwon;Choi, Jae-Hoon;Lee, Jin-Hyo;You, Young-June
    • Archives of Plastic Surgery
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    • v.38 no.6
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    • pp.845-850
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    • 2011
  • Purpose: In general, orientals including Korean, have a mesocephalic face whereas Caucasians, among the western, have a dolichocephalic face. Unlike the western, in orientals including Korean, prominent malar bones are recognized as stubborn and unattractive appearance. That is why reduction malarplasty is one of the most popular aesthetic surgical procedure in Korea. Many surgical methods to reposition prominent malar bones have been performed by means of a coronal incision or a combined incisions, using both the intraoral and the external incision. Bicoronal approach has advantage such as wide operative field, easy to maintain symmetry and possibility of combining facial lift but has shortcoming, such as external scars, long operative time, and the possibility of facial nerve or artery injury. Intraoral approach has advantages of short operative time, simplicity of procedure and no external scar. But this approach is associated with problems of cheek drooping, limited exposure and difficulty in making symmetry. Methods: During 8 years, we performed a reduction malarplasty without internal fixation through an minimal intraoral incision and dissection in 39 patients. Results: The patients were followed for 46 months, with satisfactory results and no cheek drooping. There was no patient who want to revise the inappropriate operative result such as asymmetry and incomplete correction. Conclusion: We conclude that minimal intraoral incision and dissection could acquire satisfactory result of reduction malarplasty along with prevention of cheek drooping.

Intelligent Tuning Of a PID Controller Using Immune Algorithm (면역 알고리즘을 이용한 PID 제어기의 지능 튜닝)

  • Kim, Dong-Hwa
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.1
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    • pp.8-17
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    • 2002
  • This paper suggests that the immune algorithm can effectively be used in tuning of a PID controller. The artificial immune network always has a new parallel decentralized processing mechanism for various situations, since antibodies communicate to each other among different species of antibodies/B-cells through the stimulation and suppression chains among antibodies that form a large-scaled network. In addition to that, the structure of the network is not fixed, but varies continuously. That is, the artificial immune network flexibly self-organizes according to dynamic changes of external environment (meta-dynamics function). However, up to the present time, models based on the conventional crisp approach have been used to describe dynamic model relationship between antibody and antigen. Therefore, there are some problems with a less flexible result to the external behavior. On the other hand, a number of tuning technologies have been considered for the tuning of a PID controller. As a less common method, the fuzzy and neural network or its combined techniques are applied. However, in the case of the latter, yet, it is not applied in the practical field, in the former, a higher experience and technology is required during tuning procedure. In addition to that, tuning performance cannot be guaranteed with regards to a plant with non-linear characteristics or many kinds of disturbances. Along with these, this paper used immune algorithm in order that a PID controller can be more adaptable controlled against the external condition, including moise or disturbance of plant. Parameters P, I, D encoded in antibody randomly are allocated during selection processes to obtain an optimal gain required for plant. The result of study shows the artificial immune can effectively be used to tune, since it can more fit modes or parameters of the PID controller than that of the conventional tuning methods.

Design of Decentralized $H^\infty$ Filter using the Generalization of $H^\infty$ Filter in Indefinite Inner Product Spaces (부정 내적 공간에서의$H^\infty$ 필터의 일반화를 통한 분산 $H^\infty$ 필터의 설계)

  • Kim, Gyeong-Geun;Jin, Seung-Hui;Yun, Tae-Seong;Park, Jin-Bae
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.6
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    • pp.735-746
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    • 1999
  • We design the robust and inherently fault tolerant decetralized$$H^infty$$ filter for the multisensor state estimation problem when there are insufficient priori informations on the statistical properties of external disturbances. For developing the proposed algorithm, an alternative form of suboptimal$$H^infty$$ filter equations are formulated by applying an alternative form of Kalman filter equations to the indefinite inner product space state model of suboptimal$$H^infty$$ filtering problems. The decentralized$$H^infty$$ filter that consists of local and central fusion filters can be designed effciently using the proposed alternative$$H^infty$$ filiter gain equations. The proposed decentralized$$H^infty$$ filter is robust against un-known external disturbances since it bounds the maximum energy gain from the external disturbances to the estimation errors under the prescribed level$$r^2$$ in both local and central fusion filters and is also fault tolerant due to its inherent redundancy. In addition, the central fusion equations between the global and local data can reduce the unnecessary calculation burden effectively. Computer simulations are made to ceritfy the robustness and fault tolerance of the proposed algorithm.

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Model Development of Change of Family Functioning with Chronic illness (만성질환으로 인한 가족기능 변화 모형 - 완성된 확장기 가족을 대상으로 -)

  • ;Hesook Suzie, Kim
    • Journal of Korean Academy of Nursing
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    • v.29 no.3
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    • pp.467-484
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    • 1999
  • The main objectives of this study were to investigate the concept of family function from the perspective of the contemporary Korean family, and to construct model of change of family function with chronic illness. The hybrid model approach was applied in which three phases(theoretical phase, empirical phase, and analytic phase) of concept development were explored for family functioning. The study was conducted from 1997 to 1998. In empirical phase, two groups of purposive samples were drawn : normal family group composed of six families without ill family member, and ill family group composed of seven families of which wives have rheumatoid arthritis. Only families with child(or children) in primary or secondary schools were included in the study. The results were as follows : In theoretical phase, six dimensions of family concept were emerged : affective, structural, control, cognitive, financial, and reproductive dimension. In order to analyse the Korean normal family function in middle class with middle-aged women, financial and reproductive dimension were not included. In empirical phase, five dimensions(affective, structural, control, cognitive, and external relationship) were found from the normal family data. External relationship dimension is very important factor as a resource of the support, especially when their parents or siblings had no help or support to them. In the affective dimension, Korean family emphasized harmony and balance rather than affective expression between couples and between parents and children. They also showed common goals of the families to solve their problems to control the family members. The priority of the goals was getting into the higher education of their children or helping their unhealthy parents or family members. Six dimensions (affective, structural, control, cognitive, external relationship, and financial) of family functions were emerged from the ill family data. From the analysis of ill family data, types of restructuring house chore after wives illness were developed : (a) negociated, (b) accomodated, and (c) isolated, enduring types. Although the dimensions of family functioning identified in this study are similar to the conceptualizations that exist in the western literature, there were distinct differences in the nature of major themes and subconcepts under these family function dimensions.

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Evaluation on the Basic Properties of Polyurethane Composite Sheet Reinforced with Non-Woven Fabric (면섬유가 보강된 폴리우레탄계 복합시트의 기초 물성 평가)

  • Kim, Ji-Hyun;Do, Seung-Bae;Park, Jeong-Won;Nam, Gee-Yoong;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.238-239
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    • 2017
  • Waterproofing is a very important process in terms of durability of buildings. The materials used for waterproofing work to protect the concrete structure from external deterioration factors. In particular, the waterproofing materials applied to the exterior of the concrete structure have various problems due to changes in the external environment and variables in the construction process. The waterproof layer is repeatedly dried and shrunk according to changes in the external moisture environment, and the surface may be deteriorated due to exposure to long-term sunlight. In the case of the roof waterproofing in the structure, the waterproof layer which does not have a sufficient curing period shows much swelling and floating phenomenon. These defects, such as swelling and lifting, account for most of the defects that occur in the waterproof layer of the concrete slabs. Generally, it is difficult to expect the same level of performance as the initial state even if the waterproofing work is repaired when a defect occurs. Therefore, it is possible to reduce the defects of the waterproof layer such as swelling and lifting by forming a waterproof layer which can be integrated with the concrete surface by using a polyurethane type waterproofing material having a relatively low defective ratio compared to other waterproofing materials. So in this study, the basic properties of polyurethane waterproof sheet reinforced with non-woven fabric are investigated in order to understand field applicability.

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