• 제목/요약/키워드: serious loss

검색결과 682건 처리시간 0.03초

Strategy for Insecticide Resistance Management Approach to IPM

  • Motoyama, Naoki;Dauterman, W.C.
    • 한국응용곤충학회지
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    • 제31권3호
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    • pp.314-327
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    • 1992
  • Insecticide resistance is a serious is a serious threat to IPM, resulting in various adverse effects not to mention the loss of yield in agriculture. One approach to counter the problem is the disruption of resistance mechanisms. This can be achieved by (1) compounds which show a negative correlation with resistance at the site of action, (2) specific metabolic inhibitors which serve as synergists, or (3) a certain combination of two insecticides producing a joint action. This approach, however, requires certain precautions for the side effects may cause an increase in toxicity to mammals. Owing to the recent advances in theoretical studies on resistance management employing computer simulation and mathematical models, a few principles to reduce the risk of development of resistance have been clarified. They are helpful in designing operational strategies with regard to, for instance, insecticide doses to be applied, mode of application, and choice and nature of the insecticide(s) to be used. For restoration of insecticide susceptibility of a resistant population, reintroduction of susceptible individuals to the resistant population is feasible when certain conditions are met. Natural enemies which developed resistance to insecticides can be an important component of IPM as has been shown in the pest management in apple orchards. After all, the implementation of a successful resistance management program depends upon cooperation between different sigments of the agricutural community. Although resistance is a preadaptive phenomenon, in some cases spontaneous loss of resistance does occur without contamination by susceptible individuals. The instability of resistance in these insects implies the possible existence of a switch machanism controlling the expression of resistance gene(s). Elucidation of such a mechanism may eventually provide us with a new technical approach with which we can combat the problem of insecticide resistance.

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RBS 성능향상을 위한 연속 클럭 동기화 및 패킷 손실 보상 기법 (Continuous Clock Synchronization and Packet Loss Tolerance Scheme for Enhancing Performance of Reference Broadcast Synchronization)

  • 트렁홉도;박근원;정재인;유명식
    • 한국통신학회논문지
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    • 제39B권5호
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    • pp.296-303
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    • 2014
  • Reference Broadcast Synchronization (RBS)는 무선 센서 네트워크 동기화에 가장 널리 사용되는 프로토콜이다. 공통의 브로드케스트 채널이 존재할 경우 RBS는 상당히 높은 동기화 성능을 보인다. 그러나 RBS는 순간 클럭 동기화 (Instantaneous Clock Synchronization) 방식을 사용기 때문에 동기화 시간에 순간적인 시간 간격이 발생하여 시스템의 불안정을 초래할 수 있다. 또한 RBS는 패킷 손실 보상 기능이 없어 무선 채널 환경이 열악한 경우 동기화 성능의 현저한 저하를 초래할 수 있다. 본 논문에서는 RBS의 순간 클럭 동기화에 의한 문제점과 패킷 손실이 BRS 동기화에 미치는 영향에 대해서 분석한다. 이러한 문제점을 해결하기 위하여 RBS를 위한 연속 클럭 동기화 방식과 패킷 손실 보상 방식을 제안하고, 모의실험을 통하여 제안 방식의 성능향상에 대해 검증하고자 한다.

무선 센서 네트워크를 위한 Hop-by-Hop 기반의 신뢰성 있는 혼잡제어 기법 설계 (A Design of Hop-by-Hop based Reliable Congestion Control Protocol for WSNs)

  • 허관;김현태;나인호
    • 한국정보통신학회논문지
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    • 제10권6호
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    • pp.1055-1059
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    • 2006
  • 무선 센서 네트워크의 센서 노드는 브로드캐스트 방식을 사용하여 수집한 데이터를 이웃한 다른 센서노드로 전달하기 때문에 데이터 중복성 문제가 발생한다. 데이터 중복성은 네트워크 로드를 가중시키며 데이터 손실의 원인이 되며, 이러한 문제점은 데이터 전송의 신뢰성과 네트워크 혼잡 회피간의 상충조건에 의해 발생한다. 따라서 무선 센서 네트워크에서 효율적으로 혼잡제어를 수행하기 위해서는 신뢰성 있는 전송(reliable transmission), 무선 손실(wireless loss), 혼잡 손실(congestion loss) 등과 같은 여러 요소를 고려한 신뢰성 있는 혼잡제어 기법이 필요하다. 본 논문에서는 Hop-by-Hop 순서 번호, DSbACK(Delayed and Selective ACK, Buffer Condition)을 사용하여 신뢰성 있는 전송을 보장하고 불필요한 전송을 최소화한 에너지 절약형 혼잡 제어 기법으로 HRCCP(Hop-by-Hop Reliable Congestion Control Protocol)를 제안하여 무선 센서 네트워크에서 신뢰성 있는 전송과 흔잡 제어가 동시에 이루어 질수 있도록 하였다.

무선 센서 네트워크를 위한 Hop-by-Hop 기반의 신뢰성 있는 혼잡제어 기법 설계 (A Design of Hop-by-Hop based Reliable Congestion Control Protocol for WSNs)

  • 허관;김현태;양해권;나인호
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2006년도 춘계종합학술대회
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    • pp.442-445
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    • 2006
  • 무선 센서 네트워크에서 다수의 센서들은 데이터를 브로드캐스트하기 때문에 데이터의 중복성을 가진다. 데이터의 중복성은 네트워크 로드를 가중시키며 데이터 손실의 원인이 된다. 이러한 문제점들은 데이터 전송의 신뢰성과 네트워크 혼잡 회피 간의 상충조건을 발생시킨다. 따라서 무선 센서 네트워크에서 효율적으로 혼잡제어를 수행하기 위해서는 신뢰성 있는 전송(reliable transmission), 무선 손실(wireless loss), 혼잡 손실(congestion loss) 등과 같은 여러 요소를 고려한 신뢰성 있는 혼잡제어 기법이 필요하다. 본 논문에서는 Hop-by-Hop 순서 번호, DSbACK(Delayed and Selective ACK, Buffer Condition)을 사용하여 신뢰성 있는 전송을 보장하고 불필요한 전송을 최소화한 에너지 절약형 혼잡 제어 기법으로 HRCCP(Hop-by-Hop Reliable Congestion Control Protocol)를 제안하여 무선 센서 네트워크에서 신뢰성 있는 전송과 혼잡 제어가 동시에 이루어질 수 있도록 하였다.

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가미 태음조위탕과 저열량 식이를 병행한 체중 감량 프로그램에서 발생한 이상 반응 분석 (Analysis of Adverse Events in Weight Loss Program in Combination with 'Gamitaeeumjowee-Tang' and Low-Calorie Diet)

  • 윤나라;유영재;김민지;김서영;임영우;임형호;박영배
    • 한방비만학회지
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    • 제18권1호
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    • pp.1-9
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    • 2018
  • Objectives: The objective of this study was to assess the safety of 'Gamitaeeumjowee-tang' by analyzing adverse events in weight loss program in combination with 'Gamitaeeumjowee-tang' and low-calorie diet. Methods: A retrospective review of adverse events in weight loss program in combination with 'Gamitaeeumjowee-tang' and low-calorie diet from the electronic medical chart (n=124) between June 2015 and December 2016 was conducted. Three Korean Medicine Doctors (KMDs) reviewed adverse events for two times, during week 2 to 4 and at week 10, after starting weight loss program. Adverse events were evaluated in terms of causality, severity and system-organ classes. Also, agreement among the three KMDs was made through further discussion in case of disagreement after independent review. Results: The overall rate of adverse events was 37.1% during week 2 to 4 and 16.9% at week 10. For causality of adverse events using the World Health Organization-Uppsala Monitoring Centre causality categories, 52.2% were evaluated 'possible' at week 2-4 and 57.1% were evaluated 'unlikely' at week 10. All symptoms were evaluated as 'mild' by LDS scale. Nausea (15, 12.1%) was the most frequent adverse event at week 2-4 and dizziness (6, 4.8%) was the most common at week 10. Conclusions: Adverse events decreased over time. There were no serious adverse events and none of the subjects were dropped due to adverse events. Continuous study is needed to prove the safety of 'Gamitaeeumjowee-tang' for treating obesity.

고랭지밭의 구거복원에 따른 토양유실저감 효과분석 (Analysis of Effect of Ditch Restoration on Soil Loss Reduction in Highland Agricultural Fields)

  • 성윤수;김동진;이수인;류지철;김종건;임경재;김기성
    • 한국물환경학회지
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    • 제36권5호
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    • pp.385-391
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    • 2020
  • Soil loss is a serious problem frequently caused by local torrential rainfalls due to climate change. In particular, soil loss is occurring in agricultural areas rather than urban areas, and many pollutants are introduced into rivers, causing environmental problems. To reduce soil loss, the Ministry of Environment has designated and managed non-point source management areas. The Jaun-district in Hongcheon-gun, which was designed as a non-point pollution source management area in Gangwon-do, is located in the upper stream of Soyang Lake. Most of the agricultural fields are composed of highland agriculture fields. The highland agricultural fields in the Jaun-district are also composed of large-scale farming areas, and the ditches located near the agricultural fields have been illegally used for farmland. Therefore, the local government in Hongcheon-gun is conducting a project to restore the ditches occupied by agricultural fields. However, an analysis of the amount of soil loss that can be reduced by the restoration of the ditches has not been conducted yet. Thus, the purpose of this study was to analyze the effect of reducing the soil loss from the restoration of the ditches used as agricultural fields in the Jaun-district. The SATEEC L Module was used to analyze the reduction in soil loss by ditch restoration. The SATEEC L Module was constructed to estimate the LS factor using Moore and Burch's method after calculating the slope length using the digital elevation model and the maximum allowable slope length. The LS factor and the USLE formula were used to estimate the amount of soil loss that could be reduced by ditch restoration. The analysis showed that the ditch restoration could reduce about 16.6% of the soil loss in the Jaun-district. The results of this study will contribute to the study of methods to reduce soil loss in non-point pollution management areas.

시변 시간지연 하에서 안정성을 보장하는 양방향 원격제어기 : 시간영역 수동성 기법 (Bilateral Controller for Time-varying Communication Delay: Time Domain Passivity Approach)

  • 유지환
    • 제어로봇시스템학회논문지
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    • 제13권11호
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    • pp.1099-1105
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    • 2007
  • In this paper, modified two-port time-domain passivity approach is proposed for stable bilateral control of teleoperators under time-varying communication delay. We separate input and output energy at each port of a bilateral controller, and propose a sufficient condition for satisfying the passivity of the bilateral controller including time-delay. Output energy at the master port should be less than the transmitted input energy from the slave port with time-delay, and output energy at the slave port should be less than the transmitted input energy from the master port with time-delay. For satisfying above two conditions, two passivity controllers are attached at each port of the bilateral controller. A packet reflector with wireless internet connection is used to introduce serious time-varying communication delay of teleoperators. Average amount of time-delay was about 190(msec) for round trip, and varying between 175(msec) and 275(msec). Moreover some data packet was lost during the communication due to UDP data communication. Even under the serious time-varying delay and packet loss communication condition, the proposed approach can achieve stable teleoperation in free motion and hard contact as well.

Valproic Acid-Induced Hyperammonemic Encephalopathy as a Cause of Neurologic Deterioration after Unruptured Aneurysm Surgery

  • Lee, Sangkook;Cheong, Jinhwan;Kim, Choonghyun;Kim, Jae Min
    • Journal of Korean Neurosurgical Society
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    • 제58권2호
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    • pp.159-162
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    • 2015
  • Neurological deficits after brain surgery are not uncommon, and correct and prompt differential diagnosis is essential to initiate appropriate treatment. We describe a patient suffering from loss of consciousness due to hyperammonemia, following valproic acid treatment after surgery for an unruptured cerebral aneurysm. A 57-year-old female patient underwent successful aneurysmal neck clipping to correct an unruptured aneurysm. Her postoperative course was good, and she received anti-epileptic therapy (valproic acid) and a soft diet. Within a few days the patient experienced mental deterioration. Her serum valproic acid reached toxic levels (149.40 mg/L), and serum ammonia was fifteen times the upper normal limit (553 mmol/L; normal range, 9-33 mmol/L). After discontinuation of valproic acid and with conservative treatment, the patient recovered without any complications. Valproate-induced hyperammonemic encephalopathy is an unusual but serious neurosurgical complication, and should not be disregarded as a possible cause of neurological deficits after neurovascular surgery. Early diagnosis is crucial, as discontinuation of valproic acid therapy can prevent serious complications, including death.

Analysis of Leak and Water Absorption Test Results for Water-Cooled Generator Stator Windings

  • Kim, Hee-Soo;Bae, Yong-Chae;Lee, Wook-Ryun;Lee, Doo-Young;Kim, Hee-Dong
    • Journal of Electrical Engineering and Technology
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    • 제7권2호
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    • pp.230-235
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    • 2012
  • Cases of insulation breakdown damage of water-cooled generator stator windings occur frequently due to coolant leakage and water absorption worldwide. Such serious accidents may cause not only enormous economic loss but also very serious grid accidents in terms of stable supply of electric power. More than 50 % of domestic generators have been operated for more than 15 years, and leak and water absorption problem of windings are often found during the planned preventive maintenance period. Since 2005, leak and water absorption tests have been performed for total watercooled stator windings after fully drying the inside of the windings. The results are then comprehensively analyzed. The result of the test performed by GE, a foreign manufacturer, for 141 generators showed failures in 80 of them (failure rate: 57 %), whereas in the tests carried out in Korean domestic power plants, only 14 out of 50 generators showed failures (failure rate: 28 %).

Protection of a Multicast Connection Request in an Elastic Optical Network Using Shared Protection

  • BODJRE, Aka Hugues Felix;ADEPO, Joel;COULIBALY, Adama;BABRI, Michel
    • International Journal of Computer Science & Network Security
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    • 제21권1호
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    • pp.119-124
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    • 2021
  • Elastic Optical Networks (EONs) allow to solve the high demand for bandwidth due to the increase in the number of internet users and the explosion of multicast applications. To support multicast applications, network operator computes a tree-shaped path, which is a set of optical channels. Generally, the demand for bandwidth on an optical channel is enormous so that, if there is a single fiber failure, it could cause a serious interruption in data transmission and a huge loss of data. To avoid serious interruption in data transmission, the tree-shaped path of a multicast connection may be protected. Several works have been proposed methods to do this. But these works may cause the duplication of some resources after recovery due to a link failure. Therefore, this duplication can lead to inefficient use of network resources. Our work consists to propose a method of protection that eliminates the link that causes duplication so that, the final backup path structure after link failure is a tree. Evaluations and analyses have shown that our method uses less backup resources than methods for protection of a multicast connection.