• Title/Summary/Keyword: Sampled-data control system

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Initial Change of Coleopteran Insect Community Affected by Anthropogenic Disturbances within Pine tree Forest (소나무림내 인위적 간섭에 따른 딱정벌레류 곤충 군집의 초기 변화에 관한 연구)

  • Roh, Seung Jin;Son, Jae Deok;Jeon, Jun Hyoung;Bae, Kwan-Ho;Kim, Hyun-Seop;Park, Sang Wook;Byun, Bong-Kyu
    • Korean Journal of Environment and Ecology
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    • v.29 no.4
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    • pp.539-551
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    • 2015
  • This study was carried out to investigate the changing pattern of forest insect communities in 2013 after harvesting of forest in 2012, and provide a basic data for the method of efficient management for preservation of forest biodiversity. Five types of cutting method in pine tree forest were selected to compare the coleopteran insect communities at Hajang-myeon, Gangwon-do, Korea, in 2013. In this study, we investigated the effects of timber harvest with green-tree retention on coleopteran insects. They were sampled with Lindgren funnel traps for five experimental sites during July to October, 2013. A total of 1,112 individuals in 156 species of 40 families by Lindgren funnel traps. Also, the analysis of coleopteran insects community was performed. Although the difference of density is not prominent among the survey areas in the early stages, it was appeared a tendency to increase in density and abundance of insects in the experimented sites excluding the control areas. Among them, strip clear-cutting area showed a increase of density and abundance in this study.

A Hybrid Forecasting Framework based on Case-based Reasoning and Artificial Neural Network (사례기반 추론기법과 인공신경망을 이용한 서비스 수요예측 프레임워크)

  • Hwang, Yousub
    • Journal of Intelligence and Information Systems
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    • v.18 no.4
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    • pp.43-57
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    • 2012
  • To enhance the competitive advantage in a constantly changing business environment, an enterprise management must make the right decision in many business activities based on both internal and external information. Thus, providing accurate information plays a prominent role in management's decision making. Intuitively, historical data can provide a feasible estimate through the forecasting models. Therefore, if the service department can estimate the service quantity for the next period, the service department can then effectively control the inventory of service related resources such as human, parts, and other facilities. In addition, the production department can make load map for improving its product quality. Therefore, obtaining an accurate service forecast most likely appears to be critical to manufacturing companies. Numerous investigations addressing this problem have generally employed statistical methods, such as regression or autoregressive and moving average simulation. However, these methods are only efficient for data with are seasonal or cyclical. If the data are influenced by the special characteristics of product, they are not feasible. In our research, we propose a forecasting framework that predicts service demand of manufacturing organization by combining Case-based reasoning (CBR) and leveraging an unsupervised artificial neural network based clustering analysis (i.e., Self-Organizing Maps; SOM). We believe that this is one of the first attempts at applying unsupervised artificial neural network-based machine-learning techniques in the service forecasting domain. Our proposed approach has several appealing features : (1) We applied CBR and SOM in a new forecasting domain such as service demand forecasting. (2) We proposed our combined approach between CBR and SOM in order to overcome limitations of traditional statistical forecasting methods and We have developed a service forecasting tool based on the proposed approach using an unsupervised artificial neural network and Case-based reasoning. In this research, we conducted an empirical study on a real digital TV manufacturer (i.e., Company A). In addition, we have empirically evaluated the proposed approach and tool using real sales and service related data from digital TV manufacturer. In our empirical experiments, we intend to explore the performance of our proposed service forecasting framework when compared to the performances predicted by other two service forecasting methods; one is traditional CBR based forecasting model and the other is the existing service forecasting model used by Company A. We ran each service forecasting 144 times; each time, input data were randomly sampled for each service forecasting framework. To evaluate accuracy of forecasting results, we used Mean Absolute Percentage Error (MAPE) as primary performance measure in our experiments. We conducted one-way ANOVA test with the 144 measurements of MAPE for three different service forecasting approaches. For example, the F-ratio of MAPE for three different service forecasting approaches is 67.25 and the p-value is 0.000. This means that the difference between the MAPE of the three different service forecasting approaches is significant at the level of 0.000. Since there is a significant difference among the different service forecasting approaches, we conducted Tukey's HSD post hoc test to determine exactly which means of MAPE are significantly different from which other ones. In terms of MAPE, Tukey's HSD post hoc test grouped the three different service forecasting approaches into three different subsets in the following order: our proposed approach > traditional CBR-based service forecasting approach > the existing forecasting approach used by Company A. Consequently, our empirical experiments show that our proposed approach outperformed the traditional CBR based forecasting model and the existing service forecasting model used by Company A. The rest of this paper is organized as follows. Section 2 provides some research background information such as summary of CBR and SOM. Section 3 presents a hybrid service forecasting framework based on Case-based Reasoning and Self-Organizing Maps, while the empirical evaluation results are summarized in Section 4. Conclusion and future research directions are finally discussed in Section 5.

A Study of the Relationship to the Student's Health Behavior, Belief, Value and Health Service Utilization -With Emphasis on Family Structure and Other Variables- (학생(學生)의 건강행위(健康行爲), 신념(信念), 가치(價値) 및 보건의료(保建醫療) 이용(利用)에 미치는 영향(影響)에 관(關)한 연구 -가족(家族)의 형태(形態) 및 제특성(諸特性)을 중심(中心)으로-)

  • Chung, Yeon Kang
    • Journal of the Korean Society of School Health
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    • v.6 no.1
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    • pp.9-44
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    • 1993
  • An explorative and descriptive study in order to determine the effect of family structure and other socio-demographic variables on health behavior, belief, locus, and value and utilization of public health service was carried out. Data were collected from 1,653 subjects randomly sampled in three areas, Seoul, Kyunggi province, and Cheju province. From Seoul 849 subjects were selected, 397 subjects Kyunggi, and 407 subjects from Cheju, respectively. Self-reporting questionaires were administered during the period from March to June, 1992. The major findings were as follows: 1) The subjects visited herb-doctor's at irregular intervals mainly to have tonic medicine prepared. They preferred herb-doctor's rather than with doctors at clinics and hospitals. Statistically significant difference was found among the regions studied (p<0.05). 2) The reason for visiting hospitals was primarily for treatment of diseases. They preferred hospital because they felt that the hospitals offer much highly reliable treatment services as well as medical accessibility. For the purpose of hospital utilization, statistically significant differences existed among sex, educational level, family type and region. However, no significance was found among sex, educational level, and region (p<0.05). 3) The subjects utilized general hospitals mainly for diagnosis and treatment of diseases. They preferred general hospitals because of their much better facilities and reliability. Statistical significance was found among sex, educational level, and region (p<0.05). 4) The subjects visited dentist at irregular intervals basis. They visited once half a year or three to four months. their purpose of visit was mainly for diagnosis and treatment of diseases. Statistical significance differences were found among educational level, region and economic standard (p<0.05). 5) Whenever their illnesses were mild and the pharmacies was located in nearby they visited to pharmacies. They visited once a month and patient medicines. Statistically significant differences were found among sex, educational level and region (p<0.05). 6) The subjects believed that herb medicine was quite efficacious for treatment of some diseases, particularly by information handed down through time-honored tradition and experience. However, they recognized that the efficacy of folk medicine can vary with type and severity of diseases. Statistical significance was among sex, educational level, region and economic standard (p<0.05). 7) The reason why subjects believed that pray and superstition are effective for treatment of certain type of diseases, particularly in neuropathy, was the belief in God's almighty. Statistically significant differences were found among sex, educational level, regions and economic standard (p<0.05). 8) Most of subjects under same condition preferred western medicine because they believed that it is more scientific and prompts in showing therapeutic effect. Statistical significance was not found in the choice of type of public health service among, regions. But significant differences were found among sex, educational level and region (p<0.05). 9) The subjects looked for pharmacy if they thought the symptom was mild. However, they visited hospitals for chronic disease and general hospitals for emergency treatment. Statistical significances were found among educational level, region and economic standard (p<0.05). 10) Although most of students wanted to have a healthy life as for the component of health standard and value, they think that they are not healthy (p<0.05). As for the health behavior, significant difference was found in the proportion of smoking and drinking between educational level and region (p<0.05). The health locus was affected by educational level, and health behavior was influenced by region, sex and educational level. The utilization of type of public health service was influenced by family type and region, and health belief by region and educational level, and the health values by region and economic standard respectively, most of correlation showed statistical significance. Among them, the highest correlation was seen between locus of control and external/internal locus of control, which is quite obvious. The correlation between health belief and behavior was the next highest, but still low (0.343). All the other variables are low but significant except only a few of those. These findings indicate that health education should be incorporated into the curriculum so as to develop desirable health habit, and ability of self-control in accordance with their growth stages. A systematic and scientific understanding on the herb/folk medicine is needed, and greater reliability of the utilization of public health services are is still required. Health policy for equal distribution of health service throughout the country along the hierarchical health service system and complementary mutual assistance and cooperation among various health organizations are also required.

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Changes of Blood Gases, Plasma Catecholamine Concentrations and Hemodynamic Data in Anesthetized Dogs during Graded Hypoxia Induced by Nitrous Oxide (아산화질소에 의한 점진적 저산소가스 흡입이 혈중 가스치와 Catecholamine치 및 혈역학에 미치는 영향)

  • Kim, Sae-Yeon;Song, Sun-Ok;Bae, Jung-In;Cheun, Jae-Kyu;Bae, Jae-Hoon
    • Journal of Yeungnam Medical Science
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    • v.15 no.1
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    • pp.97-113
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    • 1998
  • The sympathoadrenal system plays an important role in homeostasis in widely varing external environments. Conflicting findings, however, have been reported on its response to hypoxia. We investigated the effect of hypoxia on the sympathoadrenal system in dogs under halothane anesthesia by measuring levels of circulating catecholamines in response to graded hypoxia. Ten healthy mongreal dogs were mechanically ventilated with different hypoxic gas mixtures. Graded hypoxia and reoxygenation were induced by progressively decreasing the oxygen fraction in the inhalation gas mixture from 21%(control) to 15%, 10% and 5% at every 5 minutes, and then reoxygenated with 60% oxygen. Mean arterial pressure, central venous pressure and mean pulmonary arterial pressure were measured directly using pressure transducers. Cardiac output was measured by the thermodilutional method. For analysis of blood gas, saturation and content, arterial and mixed venous blood were sampled via the femoral and pulmonary artery at the end of each hypoxic condition. The concentration of plasma catecholamines was determined by radioenzymatic assay. According to the exposure of graded hypoxia, not only did arterial and mixed venous oxygen tension decreased markedly at 10% and 5% oxygen, but also arterial and mixed venous oxygen saturation decreased significantly. An increased trend of the oxygen extraction ratio was seen during graded hypoxia. Cardiac output, mean arterial pressure and systemic vascular resistance were unchanged or increased slightly. Pulmonary arterial pressure(PAP) and pulmonary vascular resistance(PVR) were increased by 55%, 76% in 10% oxygen and by 82%, 95% in 5% oxygen, respectively(p<0.01). The concentrations of plasma norepinephrine, epinephrine and dopamine increased by 75%, 29%, 24% in 15% oxygen and by 382%, 350%, 49% in 5% oxygen. These data suggest that the sympathetic nervous system was activated to maintain homeostasis by modifying blood flow distribution to improve oxygen delivery to tissues by hypoxia, but hemodynamic changes might be blunted by high concentration of nitrous oxide except PAP and PVR. It would be suggested that hemodynamic changes might not be sensitive index during hypoxia induced by high concentration of nitrous oxide exposure.

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