• Title/Summary/Keyword: Dead-Time

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Effects of an Antimicrobial Substance from Bombycis corpus on Antibiotic Resistant Microbes (백강잠으로부터 분리한 항균물질의 항생제 내성균에 대한 효과)

  • Lee, Hyeon-Woo;Um, Jeong-Sun;Ko, Mi-Kyung;Kim, Mi-Kyung;Eun, Jae-Soon;Jeon, Hoon;Leem, Jae-Yoon
    • YAKHAK HOEJI
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    • v.51 no.4
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    • pp.253-258
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    • 2007
  • Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram- positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin-resistant enterococci (VRE), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.

An Enhanced AODV based Energy-aware Routing Protocol for Route Maintenance in MANET (배터리 용량을 고려한 개선된 AODV 라우팅 알고리즘)

  • Kim Kwan-Woong;Lee Jeong-Soo;Pan Ce;Chung Kyung-Taek;Chon Byoung-Sil
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.4 s.346
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    • pp.22-30
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    • 2006
  • In this paper, the goal of our proposed algorithm is to reduce link -failure and route failure caused by dead nodes which consume all of the battery life. I propose an algorithm which provides a ability of changing mutes to neighbor nodes before some of intermediate nodes be shutting don to get the stable route maintenance. To achieve this goal, The proposed routing algerian uses additional new messages to check energy status for monitoring energy of neighbor nodes and to change the path to a neighbor node. From extensive simulations, results show that possibility of cut-offs and time-delay cause of packet-loss have been decreased and also the improvement of transmission effectiveness.

Half-Scaled Substructure Test for the Performance Evaluation of a Transmission Tower subjected to Wind Load (송전철탑의 내풍안전성 평가를 위한 1/2축소부분구조 실험)

  • Moon, Byoung-Wook;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.5
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    • pp.641-652
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    • 2007
  • In this paper, a half-scaled substructure test was performed to evaluate the buckling and structural safety of an existing transmission tower subjected to wind load. A loading scheme was devised to reproduce the dead and wind loads of a prototype transmission tower, which uses a triangular jig that is mounted on the reduced model to which the similarity law of a half length was applied. As a result of the preliminary numerical analysis carried out to evaluate the stability of a specimen for the design load, is was confirmed that the calculated axial forces of tower leg members were distributed to $80{\sim}90%$ of an admissible buckling load. When the substructured transmission tower was loaded by 270% of its maximum admissible buckling load, it was failed due to the local buckling that is occurred in joints with weak constraints for out-of-plane behavior of leg members. By inspection of load-displacement curves, displacements and strains of members, it is considered that this local buckling was due to additional eccentric force by unbalanced deformation because the time that is reached to yielding stress due to the bending moment is different at each point of a same section.

An Inquiry into the Taboo of the Burial Shroud (수의의 금기에 관한 고찰)

  • 남민이
    • The Research Journal of the Costume Culture
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    • v.7 no.3
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    • pp.50-57
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    • 1999
  • Folk belief, which originated with the rise of human existence is a fundamental and comprehensive mode of living that reflects sociocultural conditions. Adherents of folk belief accept a certain thing to be true and real without scientific authority and absolute certainty. Taboo can be seen as a king of folk belief. The object of this study is to examine the taboos in relation to the manufacturing process and the quality of the shroud and to shrouding customs. I will also try to find out the meaning and significance in this. Through this task, I hope to contribute to the enhanced understanding of the cultural characteristics, the spiritual life, and the views on after life of the Korean people. In Korea, it is considered to be propitious to prepare the shroud on the intercalary month of the leap year , as it allows one to enjoy longevity healthy and sound. Moreover, as this belief gives credence and repose while preparing for the “final departure”, this custom is relatively well observed. From the taboo concerning leap months, we infer that death as viewed as a commencement of a new life, which reveals a positive view on afterlife. This can be seen as a return to the origin of anti-universal space in this “bonus” month of anti-universal time. Taboos on the manufacturing process of the shroud is related to the belief that it allows the deceased to go the nest world without any hesistation or disturbances. This symbolizes the immortality of the human soul: I. e. that the human spirit does not end in this world but continues on to the next. Taboos concerning the preparation process of the shroud as well as various other taboos are related to the belief that preparation for the shroud should be done in sincerity and secredness with a thoughtful consideration for the deceased. This can be perceived as an implication to sanctity for the dead.

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Experiments of Unmanned Underwater Vehicle's 3 Degrees of Freedom Motion Applied the SLAM based on the Unscented Kalman Filter (무인 잠수정 3자유도 운동 실험에 대한 무향 칼만 필터 기반 SLAM기법 적용)

  • Hwang, A-Rom;Seong, Woo-Jae;Jun, Bong-Huan;Lee, Pan-Mook
    • Journal of Ocean Engineering and Technology
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    • v.23 no.2
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    • pp.58-68
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    • 2009
  • The increased use of unmanned underwater vehicles (UUV) has led to the development of alternative navigational methods that do not employ acoustic beacons and dead reckoning sensors. This paper describes a simultaneous localization and mapping (SLAM) scheme that uses range sonars mounted on a small UUV. A SLAM scheme is an alternative navigation method for measuring the environment through which the vehicle is passing and providing the relative position of the UUV. A technique for a SLAM algorithm that uses several ranging sonars is presented. This technique utilizes an unscented Kalman filter to estimate the locations of the UUV and surrounding objects. In order to work efficiently, the nearest neighbor standard filter is introduced as the data association algorithm in the SLAM for associating the stored targets returned by the sonar at each time step. The proposed SLAM algorithm was tested by experiments under various three degrees of freedom motion conditions. The results of these experiments showed that the proposed SLAM algorithm was capable of estimating the position of the UUV and the surrounding objects and demonstrated that the algorithm will perform well in various environments.

The Optimization of Fuzzy Logic Controllers Using Genetic Algorithm (유전 알고리듬을 이용한 퍼지 제어기의 최적화)

  • Chang, Wook;Park, Jin-Bae;Joo, Young-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.7 no.4
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    • pp.48-57
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    • 1997
  • This paper presents the automatic construction and parameter optimization technique for fuzzy logic controllers using genetic algorithm. In general. the design of fuzzy logic controllers has difficulties in the acq~lisition of expert's knowledge and relies to a great extent on empirical and heuristic knowledge which, in many cases, cannot be objectively justified. So, the performance of the controllers c:an be degraded in the case of plant parameter variations or unpredictable incident which a designer may have ignored, and the parameters of fuzzy logic controllers obtained by expert's control action may not be optirnal. Some of these problems can be resolved by the use of genetic algorithm. The proposed method can tune the parameters of fuzzy logic controllers including scaling factors and determine: the appropriate number of fuzzy rulcs systematically. Finally, we provides the second order dead time plant to evaluate the feasibility and generality of the proposed method. Comparison shows that the proposed method can produce fuzzy logic controllers with higher accuracy and a smaller number of fuzzy rules than manually tuned fuzzy logic controllers.

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Thirteen Weeks Repeated Oral Dose Toxicity Study of Oplopanax elatus (Nakai) Nakai Hydrothermal Extract Powder in Sprague-Dawley Rats (Sprague-Dawley 랫드를 이용한 땃두릅나무 열수추출물 분말의 13주 반복 경구투여 독성에 관한 연구)

  • Yoo, Nam Ho;Kwon, Yongsoo;Chun, Hyeon Soo;An, Kyu Sup;Kim, Hye Jin;Ryu, Hyeon Yeol;Lee, So Min;Song, Kyung Seuk;Park, Byung Jun;Kim, Myong Jo
    • Korean Journal of Pharmacognosy
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    • v.50 no.4
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    • pp.260-271
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    • 2019
  • This study aimed to evaluate the safety of Oplopanax elatus (Nakai) Nakai hydrothermal extract powder. It was conducted using male and female Sprague-Dawley (SD) rats. The test group was established with dose of 500 (low-dosage group), 1,000 (medium- dosage group), and 2,000 (high- dosage group) mg/day. These are investigated that number of dead animals, general symptoms, weight changes, food consumption, ophthalmological examination, urinalysis, urine volume, hematological values, plasma coagulation time values, serum biochemical values, absolute organ weight, relative organ weight and histopathological finding during the experiment. As a result of the above, toxicological changes were not observed. Therefore, the non-toxic content of Oplopanax elatus (Nakai) Nakai hydrothermal extract powder is determined to be 2,000 mg/kg/day, and target organ was not observed.

Thecooperative relationship between chemotherapy and the host immune response in immunosuppressed or immunostimulated mice infected with Fasciola hepatica (면역억압 또는 면역활성된 마우스에 간질(Fasciola hepatica)을 감염시킨 후 관찰되는 약물요법과 숙주의 면역기전과의 상호협력관계)

  • Shin, Sung-shik;Kim, Cheol-hee
    • Korean Journal of Veterinary Research
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    • v.40 no.3
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    • pp.575-585
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    • 2000
  • This study was performed to observe the influence of host immune response on the chemotherapy of mice experimentally infected with Fasciola hepatica. Following immunosuppression with prednisolone or immunoenhancement with Freund's complete adjuvant(FCA), mice were experimentally infected with 3 Fasciola hepatica metacercariae and treated with closantel at 1 week post infection. In the group of mice infected with metacercariae alone, 2 mice of 10 were dead at 10 weeks post infection(20% mortality), and adult flukes were recovered from the liver and the peritoneal cavity of the remaining 8 mice(100% infectivity). In the group of mice treated with prednisolone and infected with metacercariae, 8 of 10 mice died before euthanasia with a mean time of death earlier than the control group (p<0.05). In the group of immunosuppressed mice infected with metacercariae and treated with closantel 20mg/kg, 4 of 10 mice died before sacrifice. In the group of mice infected and treated with closantel 20mg/kg, mortality and infectivity was 10% and 30%, respectively. Similar results were observed in mice infected and treated with closantel 5mg/kg which resulted in 10% and 50% mortality and infectivity, respectively. These results indicated that the efficacy of closantel treatment was decreased in immunosuppressed mice, while the pathogenicity was increased. In immunoenhanced mice infected with metacercariae, on the other hand, the efficacy of chemotherapy with both 5mg/kg or 20mg/kg closantel resulted in only 10% infectivity. The results shown in this study strongly suggest that a close interaction between chemotherapy against F hepatica with closantel and the host immune system exists. Considering that fascioliasis is a zoonosis, treatment regimen against the infection to immunosuppressed patients may require a concurrent prescription of an appro-priate immuno-enhancing adjuvant.

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The First Successful Heart-Lung Transplantation in Korea (심장-폐이식 1례보고)

  • 박국양;김주이;박철현;김상익;김정철;현성열;심현자;정미진;권진형
    • Journal of Chest Surgery
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    • v.31 no.6
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    • pp.610-614
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    • 1998
  • The first heart-lung transplantation in Korea was successfully performed. The recipient was a 11 year old girl with pulmonary atresia with intact ventricular septum. She had been catheterized at the ages of 4 months, 3 years, 7 years and 10 years, which revealed that neither Fontan nor biventricular repair was feasible. The donor was a traffic accident victim, a 9 year-old boy with the same blood type. The donor was pronounced dead according to the guidelines of the Korean Medical Association's Brain Death Committee. The operation was performed on April 20, 1997. The native heart-lung block was explanted segmentally and donor one was placed above the phrenic nerve using the Arizona technique. After the tracheal anastomosis with single continuous 4-0 prolene, both vena cavae were anastomosed, followed by aortic anastomosis. The graft ischemic time was 145 minutes. The postoperative course was complicated by fever and tracheal stenosis at the anastomosis site. The fever was controlled by anti-tuberculous medications and the tracheal stenosis was relieved by stent(Palmaz 8 mm, 30 mm in length) placement on POD #71. The patient is doing well and is very active in her 7th postoperative month.

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Effect of Milling Speed on the Structural and Magnetic Properties of Ni70Mn30 Alloy Prepared by Planetary Ball Mill Method

  • Hussain, Imad;Lee, Ji Eun;Jeon, So Eun;Cho, Hyun Ji;Huh, Seok-Hwan;Koo, Bon Heun;Lee, Chan Gyu
    • Korean Journal of Materials Research
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    • v.28 no.10
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    • pp.539-543
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    • 2018
  • We report the structural, morphological and magnetic properties of the $Ni_{70}Mn_{30}$ alloy prepared by Planetary Ball Mill method. Keeping the milling time constant for 30 h, the effect of different ball milling speeds on the synthesis and magnetic properties of the samples was thoroughly investigated. A remarkable variation in the morphology and average particle size was observed with the increase in milling speed. For the samples ball milled at 200 and 300 rpm, the average particle size and hence magnetization were decreased due to the increased lattice strain, distortion and surface effects which became prominent due to the increase in the thickness of the outer magnetically dead layer. For the samples ball milled at 400, 500 and 600 rpm however, the average particle size and hence magnetization were increased. This increased magnetization was attributed to the reduced surface area to volume ratio that ultimately led to the enhanced ferromagnetic interactions. The maximum saturation magnetization (75 emu/g at 1 T applied field) observed for the sample ball milled at 600 rpm and the low value of coercivity makes this material useful as soft magnetic material.