• 제목/요약/키워드: P2P Systems

검색결과 3,105건 처리시간 0.032초

집중의 신경해부와 정신생리 (The Neuroanatomy and Psychophysiology of Attention)

  • 이성훈;박윤조
    • 수면정신생리
    • /
    • 제5권2호
    • /
    • pp.119-133
    • /
    • 1998
  • Attentional processes facilitate cognitive and behavioral performance in several ways. Attention serves to reduce the amount of information to receive. Attention enables humans to direct themselves to appropriate aspects of external environmental events and internal operations. Attention facilitates the selection of salient information and the allocation of cognitive processing appropriate to that information. Attention is not a unitary process that can be localized to a single neuroanatomical region. Before the cortical registration of sensory information, activation of important subcortical structures occurs, which is called as an orienting response. Once sensory information reaches the sensory cortex, a large number of perceptual processes occur, which provide various levels of perceptual resolution of the critical features of the stimuli. After this preattentional processing, information is integrated within higher cortical(heteromodal) systems in inferior parietal and temporal lobes. At this stage, the processing characteristics can be modified, and the biases of the system have a direct impact on attentional selection. Information flow has been traced through sensory analysis to a processing stage that enables the new information to be focused and modified in relation to preexisting biases. The limbic and paralimbic system play significant roles in modulating attentional response. It is labeled with affective salience and is integrated according to ongoing pressures from the motivational drive system of the hypothalamus. The salience of information greatly influences the allocation of attention. The frontal lobe operate response selection system with a reciprocal interaction with both the attention system of the parietal lobe and the limbic system. In this attentional process, the search with the spatial field is organized and a sequence of attentional responses is generated. Affective, motivational and appectitive impulses from limbic system and hypothalamus trigger response intention, preparation, planning, initiation and control of frontal lobe on this process. The reticular system, which produces ascending activation, catalyzes the overall system and increases attentional capacity. Also additional energetic pressures are created by the hypothalamus. As psychophysiological measurement, skin conductance, pupil diameter, muscle tension, heart rate, alpha wave of EEG can be used. Event related potentials also provide physiological evidence of attention during information process. NI component appears to be an electrophysiological index of selective attention. P3 response is developed during the attention related to stimulus discrimination, evaluation and response.

  • PDF

MANAGING A PROLONGED STATION BLACKOUT CONDITION IN AHWR BY PASSIVE MEANS

  • Kumar, Mukesh;Nayak, A.K.;Jain, V;Vijayan, P.K.;Vaze, K.K.
    • Nuclear Engineering and Technology
    • /
    • 제45권5호
    • /
    • pp.605-612
    • /
    • 2013
  • Removal of decay heat from an operating reactor during a prolonged station blackout condition is a big concern for reactor designers, especially after the recent Fukushima accident. In the case of a prolonged station blackout condition, heat removal is possible only by passive means since no pumps or active systems are available. Keeping this in mind, the AHWR has been designed with many passive safety features. One of them is a passive means of removing decay heat with the help of Isolation Condensers (ICs) which are submerged in a big water pool called the Gravity Driven Water Pool (GDWP). The ICs have many tubes in which the steam, generated by the reactor core due to the decay heat, flows and condenses by rejecting the heat into the water pool. After condensation, the condensate falls back into the steam drum of the reactor. The GDWP tank holds a large amount of water, about 8000 $m^3$, which is located at a higher elevation than the steam drum of the reactor in order to promote natural circulation. Due to the recent Fukushima type accidents, it has been a concern to understand and evaluate the capability of the ICs to remove decay heat for a prolonged period without escalating fuel sheath temperature. In view of this, an analysis has been performed for decay heat removal characteristics over several days of an AHWR by ICs. The computer code RELAP5/MOD3.2 was used for this purpose. Results indicate that the ICs can remove the decay heat for more than 10 days without causing any bulk boiling in the GDWP. After that, decay heat can be removed for more than 40 days by boiling off the pool inventory. The pressure inside the containment does not exceed the design pressure even after 10 days by condensation of steam generated from the GDWP on the walls of containment and on the Passive Containment Cooling System (PCCS) tubes. If venting is carried out after this period, the decay heat can be removed for more than 50 days without exceeding the design limits.

푸시업플러스(Push-up plus) 운동 시 견갑골 익상 유무에 따른 어깨안정근의 근활성도 비교 (A Comparison of the Shoulder Stabilizer Muscle Activities During Push-up Plus Between Persons With and Without Winging Scapular)

  • 박준상;전혜선;권오윤
    • 한국전문물리치료학회지
    • /
    • 제14권2호
    • /
    • pp.44-52
    • /
    • 2007
  • This study was carried out to compare the muscle activities of the shoulder stabilizers between persons with and without winging scapular during push-up plus exercise (adds the scapular protraction to the general push-up exercise). For this study, eleven males with winging scapular and eleven healthy males were recruited. Surface electromyographic (EMG) activity was recorded from the serratus anterior, upper trapezius, lower trapezius, infraspinatus, and pectoralis major while the subjects performed the push-up plus. Each push-up plus was subdivided into three phases according to the elbow position which was measured using the 3-D motion analysis system: elbow flexion (EF), elbow extension (EE), and shoulder protraction phases (SP). Two-way repeated measure ANOVA (phase ${\times}$ group) were used for statistical analysis. There was significant phase by group interaction only on the EMG composition ratio of the serratus anterior (p>.05). The EMG composition ratio of the serratus anterior was significantly higher in SP than in either EF or EE however, it was not different between winging scapular and normal groups. For both groups, the EMG composition ratio of upper trapezius, lower trapezius, and pectoralis major was significantly different across the phases of push-up plus, but the infraspinatus EMG composition ratio was not. For both groups, in EF and EE phases, the EMG composition ratio of both pectoralis major and serratus anterior were relatively higher than that of other muscles. However, in both groups, the EMG composition ratio of the serratus anterior became much more predominant than that of the pectoralis major. In addition, infraspinatus activated greater than pectoralis major. These results showed that the push-up plus exercise is effective to selectively strengthen the serratus anterior for both individuals with and without winging scapular, but not equally effective for other shoulder stabilizers.

  • PDF

Tuberculosis Surveillance and Monitoring under the National Public-Private Mix Tuberculosis Control Project in South Korea 2016-2017

  • Min, Jinsoo;Kim, Hyung Woo;Ko, Yousang;Oh, Jee Youn;Kang, Ji Young;Lee, Joosun;Park, Young Joon;Lee, Sung-Soon;Park, Jae Seuk;Kim, Ju Sang
    • Tuberculosis and Respiratory Diseases
    • /
    • 제83권3호
    • /
    • pp.218-227
    • /
    • 2020
  • Background: The national Public-Private Mix (PPM) tuberculosis (TB) control project provides for the comprehensive management of TB patients at private hospitals in South Korea. Surveillance and monitoring of TB under the PPM project are essential toward achieving TB elimination goals. Methods: TB is a nationally notifiable disease in South Korea and is monitored using the surveillance system. The Korea Centers for Disease Control and Prevention quarterly generates monitoring indicators for TB management, used to evaluate activities of the PPM hospitals by the central steering committee of the national PPM TB control project. Based on the notification date, TB patients at PPM hospitals were enrolled in each quarter, forming a cohort, and followed up for at least 12 months to identify treatment outcomes. This report analyzed the dataset of cohorts the first quarter of 2016 through the fourth quarter of 2017. Results: The coverage of sputum, smear, and culture tests among the pulmonary TB cases were 92.8% and 91.5%, respectively. The percentage of positive sputum smear and culture test results were 30.7% and 61.5%, respectively. The coverage of drug susceptibility tests among the culture-confirmed cases was 92.8%. The treatment success rate among the smear-positive drug-susceptible cases was 83.2%. The coverage of latent TB infection treatment among the childhood TB contacts was significantly higher than that among the adult contacts (85.6% vs. 56.0%, p=0.001). Conclusion: This is the first official report to analyze monitoring indicators, describing the current status of the national PPM TB control project. To sustain its effect, strengthening the monitoring and evaluation systems is essential.

인도의 언어이론과 파니니 (Linguistic Theory in India and Panini)

  • 김형엽
    • 인문언어
    • /
    • 제1권2호
    • /
    • pp.123-139
    • /
    • 2001
  • In the history of linguistics in the world the scholars in India could be regarded as the representative linguists, who had provided the cornerstone of the academic development at linguistics. Without looking into the contents of Indian linguistic theories devised and developed in the past it would be almost impossible to account for the origin of descriptive linguistics and historical linguistics. These linguistics trends became full-fledged in 19 and 20 century and are still accepted by a lot of researchers in order to analyze newly revealed languages and train students only coming up the toddling level of linguistic studies. In this paper I will show how far the influence of Indian linguistics has colored the flow of linguistic growth historically. Especially through the analysis of Panini grammar I will prove the intimate relationship between the Indian linguistic theory and the generative grammar - it is the most active theory at present. The methods that Panini applied to constitute the rules like sutra include lots of information, that also could be discovered at the rules postulated in the generative grammar. One of the common features found at both linguistic theories is the simplicity of rule representation. At the generative grammar a rule has to be established without any redundancy. When certain number of sounds like p, b, m show the same phonological. change relevant to lips (labial in linguistic term) different rules need not to be given for each sound separately. It is better to find a way of putting the sounds together in a rule with grouping the 3 sounds with the shared phonetic feature 'labial'. In Panini grammar the form of a rule was decided based on the simplicity, too. For example, sutra 6.1.77 shows the phonological connection between the vowels i, u r 1 and the semi-vowels y, v, r, 1. However, it does not require to postulate 4 individual rules respectively. Instead a rule in which the vowels and the semi-vowels are involved is suggested, and linguistically the rule make it clear that the more simpler the rules will be the better they can reflect the efficiency of human language acquisition. Although the systems introduced at Panini grammar have some sense of distance from the language education itself we cannot deny the fact that the grammar formulates the a turning point of linguistic development. It is essential for us to think over the grammar from the view point of the modem linguistic theories to understand their root and trunk more thoroughly. It will also help us to predict in which way linguistic tendency will proceed to in future.

  • PDF

다양한 감지 방법을 갖고 있는 폴리디아세틸렌 기반 비표지 화학/바이오센서 (Polydiacetylene-Based Chemo-/Biosensor of Label Free System with Various Sensing Tools)

  • 박현규;박현규;정봉현
    • KSBB Journal
    • /
    • 제22권6호
    • /
    • pp.409-413
    • /
    • 2007
  • 양친성의 성질을 가진 폴리디아세틸렌 단량체를 이용한 센서는 주로 수용액 상태에서 리포좀이나 또는 다른 구조를 이용하였다. 폴리디아세틸렌은 수용액 상에서 쉽게 구조를 형성하는 장점과 여러 광학적인 특성을 가지고 있어서 다양한 목적물질의 검출을 가능하게 하였다. 디아세틸렌 단량체는 수 nm의 크기의 분자로서 LB 필름 제조 방법을 이용하면 아주 얇은 단분자층 또는 다분자층으로 필름을 형성할 수 있게 된다. 이렇게 형성된 필름은 수용액상에서 만들어진 구조체와 같은 성질을 가진다. 즉 무색으로 형성된 구조체들은 254 nm에 조사를 시키면 파란색으로 변하게 되며 650 nm 부근에서 최대 흡수 파장을 가지게 된다. 파란색으로 형성된 구조체는 다양한 외부환경 (온도, pH, 용매 등)이나 목적물질 (바이러스, 단백질, 항체, DNA, 펩타이드 등)의 결합으로 약하게는 보라색에서 강하게는 붉은색으로 변하게 된다. 색전이가 이루어진 수용액이나 필름에서는 파란색에서는 존재하지 않던 형광이 630 nm 부근에서 최대 방출 파장이 나타나기도 한다. 따라서 가시적인 방법이나 형광 검출 방법을 이용하면 색이 변한 정도에 따라 특이성의 정도를 결정할 수 있는 좋은 센서 기술이 될 것으로 사료된다. 목적 물질 검출에 대한 연구 이외에 대부분의 폴리디아세틸렌은 색전이가 이루어진 후 가역적인 현상을 보이지 않는다. 그러나 적절하게 치환된 관능기는 가역적인 성질을 부여하게 된다. 이런 성질들을 내포하면서 막대 모양과 같은 견고한 실리카 구조체의 형성에 적용할 수 있다는 연구 결과가 보고되고 있다. 그러나 구조체를 형성하는 단량체는 비특이적인 결합을 할 수 있는 관능기 (-COOH, $-NH_2$ 등)을 포함하고 있기 때문에 선택적인 센서의 개발을 위해서는 개선해야 할 부분이다. 결론적으로 보완된 다양한 구조체와 센서 적용 기술은 현재의 표지방식을 기반으로 하는 감지 기술을 대체할 수 있는 새로운 비표지 센서로의 적용이 가능할 것으로 여겨진다.

냉각방식에 따른 반냉동 돼지고기, 쇠고기와 참치의 신선도 변화 (Effects of Sub-freezing Systems on the Freshness of Pork Loin, Beef Loin and Tuna)

  • 김돈;장영기;박기환;이영춘
    • 한국식품과학회지
    • /
    • 제32권2호
    • /
    • pp.341-348
    • /
    • 2000
  • 기존 냉장고의 특선실과 새로운 냉각방식의 냉장고에 돼지고기, 쇠고기, 냉동참치를 저장하면서 그들의 품질을 비교하여 각 냉각방식의 차이가 부분 냉동식품의 품질에 미치는 영향을 조사하였다. 일반 냉장고 특선실$(-1^{\circ}C)$, 강제순환식 저장방법$(-5^{\circ}C)$, 그리고 자연대류식 저장방법$(-5^{\circ}C)$으로 저장하면서, 돼지고기와 쇠고기는 VBN, TBA, 및 수분함량을, 냉동참치는 K-value와 VBN값의 변화를 측정하였다. 저장 기간 중 모든 시료에 대해서 강제순환식 저장방법에서 수분함량이 급격히 감소하였으며 VBN의 경우도 수분함량에 영향을 받아서 강제순환방식이 다른 저장방법들보다 높은 수치를 보였다. 돼지고기의 경우 TBA값에 대한 유의적인 차이는 없었으며 쇠고기의 경우는 VBN에 대하여 유의적 차이는 나타나지 않았으나 TBA값은 일반 특선실과 자연대류식 저장방법에 대하여 유의적 차이를 보였다. 반면 포장을 한 경우는 일반 특선실과 강제순환 및 자연대류 저장방법에서 돼지고기의 품질의 차이가 발생하였다. 냉동참치는 VBN과 K-value에 대하여 일반 특선실과 자연대류식에 유의적인 차이가 있었다. 따라서 cold chamber의 온도를 $-5^{\circ}C$ 정도인 subfreezing온도로 유지하고, 자연대류 냉각방식을 적용하면 가정용 냉장고를 사용하여 육류 및 어류의 신선도를 현저히 연장시킬 수 있을 것으로 보인다.

  • PDF

R-Mode 보정국과 감시국 선정을 위한 전파환경 분석에 관한 연구 (Analysis of Propagation Environment for Selecting R-Mode Reference and Integrity Station)

  • 전중성;정해상;국승기
    • 한국항해항만학회지
    • /
    • 제45권1호
    • /
    • pp.26-32
    • /
    • 2021
  • 해양에서 정보통신기술 기반의 4차 산업혁명 확산은 고정밀 및 안정적인 위치·항법·시각·정보(PNT&D)를 요구하고 있다. 국제해사기구(IMO)와 국제항로표지협회(IALA)에서는 범지구 위성 항법 시스템(GNSS) 의존도가 증가함에 따라 취약성 경감을 위해 백업시스템을 요구하고 있어 우리나라는 R-Mode 기술개발에 관한 연구를 진행하고 있다. 시설의 중복투자를 막기 위해 기존 해상 인프라인 중파를 이용하는 DGPS(Differential Global Positioning System) 보정국과 감시국 34개소 및 초단파를 이용하는 선박자동식별장치(AIS) 기지국을 활용하고자 하며, 일부 서해 지역에서 수신신호의 세기가 미약한 전파 음영지역이 있으므로, 이를 해결하기 위해 R-Mode 보정국과 감시국 신설을 통하여 전파 음영지역을 해소하고자 한다. 따라서 본 논문에서는 주파수가 낮은 대역에서(단파대 이하) 전파가 지표면(수면)을 따라 잘 전송되는 특징이 있어 시뮬레이션과 전파측정을 하였으며, 전파전파 특성 분석을 통하여 R-Mode 보정국과 감시국 신설 후보지를 제안하고자 한다. 본 논문을 활용하여 다른 지역의 전파 음영지역을 해소하기 위해 적절한 위치에 R-Mode 보정국과 감시국 후보지를 선정할 수 있다.

Comparison of Environment, Growth, and Management Performance of the Standard Cut Chrysanthemum 'Jinba' in Conventional and Smart Farms

  • Roh, Yong Seung;Yoo, Yong Kweon
    • 인간식물환경학회지
    • /
    • 제23권6호
    • /
    • pp.655-665
    • /
    • 2020
  • Background and objective: This study was conducted to compare the cultivation environment, growth of cut flowers, and management performance of conventional farms and smart farms growing the standard cut chrysanthemum, 'Jinba'. Methods: Conventional and smart farms were selected, and facility information, cultivation environment, cut flower growth, and management performance were investigated. Results: The conventional and smart farms were located in Muan, Jeollanam-do, and conventional farming involved cultivating with soil culture in a plastic greenhouse, while the smart farm was cultivating with hydroponics in a plastic greenhouse. The conventional farm did not have sensors for environmental measurement such as light intensity and temperature and pH and EC sensors for fertigation, and all systems, including roof window, side window, thermal screen, and shading curtain, were operated manually. On the other hand, the smart farm was equipped with sensors for measuring the environment and nutrient solution, and was automatically controlled. The day and night mean temperatures, relative humidity, and solar radiation in the facilities of the conventional and the smart farm were managed similarly. But in the floral differentiation stage, the floral differentiation was delayed, as the night temperature of conventional farm was managed as low as 17.7℃ which was lower than smart farm. Accordingly, the harvest of cut flowers by the conventional farm was delayed to 35 days later than that of the smart farm. Also, soil moisture and EC of the conventional farm were unnecessarily kept higher than those of the smart farm in the early growth stage, and then were maintained relatively low during the period after floral differentiation, when a lot of water and nutrients were required. Therefore, growth of cut flower, cut flower length, number of leaves, flower diameter, and weight were poorer in the conventional farm than in the smart farm. In terms of management performance, yield and sales price were 10% and 38% higher for the smart farm than for the conventional farm, respectively. Also, the net income was 2,298 thousand won more for the smart farm than for the conventional farm. Conclusion: It was suggested that the improved growth of cut flowers and high management performance of the smart farm were due to precise environment management for growth by the automatic control and sensor.

Artificial Neural Network with Firefly Algorithm-Based Collaborative Spectrum Sensing in Cognitive Radio Networks

  • Velmurugan., S;P. Ezhumalai;E.A. Mary Anita
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제17권7호
    • /
    • pp.1951-1975
    • /
    • 2023
  • Recent advances in Cognitive Radio Networks (CRN) have elevated them to the status of a critical instrument for overcoming spectrum limits and achieving severe future wireless communication requirements. Collaborative spectrum sensing is presented for efficient channel selection because spectrum sensing is an essential part of CRNs. This study presents an innovative cooperative spectrum sensing (CSS) model that is built on the Firefly Algorithm (FA), as well as machine learning artificial neural networks (ANN). This system makes use of user grouping strategies to improve detection performance dramatically while lowering collaboration costs. Cooperative sensing wasn't used until after cognitive radio users had been correctly identified using energy data samples and an ANN model. Cooperative sensing strategies produce a user base that is either secure, requires less effort, or is faultless. The suggested method's purpose is to choose the best transmission channel. Clustering is utilized by the suggested ANN-FA model to reduce spectrum sensing inaccuracy. The transmission channel that has the highest weight is chosen by employing the method that has been provided for computing channel weight. The proposed ANN-FA model computes channel weight based on three sets of input parameters: PU utilization, CR count, and channel capacity. Using an improved evolutionary algorithm, the key principles of the ANN-FA scheme are optimized to boost the overall efficiency of the CRN channel selection technique. This study proposes the Artificial Neural Network with Firefly Algorithm (ANN-FA) for cognitive radio networks to overcome the obstacles. This proposed work focuses primarily on sensing the optimal secondary user channel and reducing the spectrum handoff delay in wireless networks. Several benchmark functions are utilized We analyze the efficacy of this innovative strategy by evaluating its performance. The performance of ANN-FA is 22.72 percent more robust and effective than that of the other metaheuristic algorithm, according to experimental findings. The proposed ANN-FA model is simulated using the NS2 simulator, The results are evaluated in terms of average interference ratio, spectrum opportunity utilization, three metrics are measured: packet delivery ratio (PDR), end-to-end delay, and end-to-average throughput for a variety of different CRs found in the network.