• Title/Summary/Keyword: Response Time Delay

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Intelligent Tuning of the Two Degrees-of-Freedom Proportional-Integral-Derivative Controller On the Distributed Control System for Steam Temperature Control of Thermal Power Plant

  • Dong Hwa Kim;Won Pyo Hong;Seung Hack Lee
    • KIEE International Transaction on Systems and Control
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    • v.2D no.2
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    • pp.78-91
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    • 2002
  • In the thermal power plant, there are six manipulated variables: main steam flow, feedwater flow, fuel flow, air flow, spray flow, and gas recirculation flow. There are five controlled variables: generator output, main steam pressure, main steam temperature, exhaust gas density, and reheater steam temperature. Therefore, the thermal power plant control system is a multinput and output system. In the control system, the main steam temperature is typically regulated by the fuel flow rate and the spray flow rate, and the reheater steam temperature is regulated by the gas recirculation flow rate. However, strict control of the steam temperature must be maintained to avoid thermal stress. Maintaining the steam temperature can be difficult due to heating value variation to the fuel source, time delay changes in the main steam temperature versus changes in fuel flow rate, difficulty of control of the main steam temperature control and the reheater steam temperature control system owing to the dynamic response characteristics of changes in steam temperature and the reheater steam temperature, and the fluctuation of inner fluid water and steam flow rates during the load-following operation. Up to the present time, the Proportional-Integral-Derivative Controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper focuses on the characteristic comparison of the PID controller and the modified 2-DOF PID Controller (Two-Degrees-Freedom Proportional-Integral-Derivative) on the DCS (Distributed Control System). The method is to design an optimal controller that can be operated on the thermal generating plant in Seoul, Korea. The modified 2-DOF PID controller is designed to enable parameters to fit into the thermal plant during disturbances. To attain an optimal control method, transfer function and operating data from start-up, running, and stop procedures of the thermal plant have been acquired. Through this research, the stable range of a 2-DOF parameter for only this system could be found for the start-up procedure and this parameter could be used for the tuning problem. Also, this paper addressed whether an intelligent tuning method based on immune network algorithms can be used effectively in tuning these controllers.

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Implementation and Performance Evaluation of Transaction Protocol for Wireless Internet Services (무선 인터넷 서비스를 위한 트랜잭션 프로토콜의 구현과 성능평가)

  • Choi, Yoon-Suk;Lim, Kyung-Shik
    • Journal of KIISE:Information Networking
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    • v.29 no.4
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    • pp.447-458
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    • 2002
  • In this paper, we design and implement Wireless Transaction Protocol(WTP) and evaluate it for wireless transaction processing in mobile computing environments. The design and implementation of WTP are based on the coroutine model that might be suitable for light-weight portable devices. We test the compatibility between our product and the other products such as Nokia, Kannel and WinWAP For the evaluation of WTP, we use an Internet simulator that can arbitrary generate random wireless errors based on the Gilbert model. In our experiment, the performance of WTP is measured and compared to those of Transmission Control Protocol(TCP) and TCP for Transactions. The experiment shows that WTP outperforms the other two protocols for wireless transaction processing in terms of throughput and delay. Especially, WTP shows much higher performance In ease of high error rate and high probability of burst errors. This comes from the fact that WTP uses a small number of packets to process a transaction compared to the other two protocols and introduces a fixed time interval for retransmission instead of the exponential backoff algorithm. The experiment also shows that the WTP performance is optimized when the retransmission counter is set to 5 or 6 in case of high burst error rate.

The Effectiveness of Traditional Korean Medicine for Treating Postoperative Ileus in Gastric Cancer Patients: A Systematic Review and Meta-Analysis (위암 수술 후 장마비에 대한 한의학적 치료의 효과 : 체계적 문헌 고찰 및 메타분석)

  • Bae, Hye-ri;Kim, Eun-ji;Seo, Hyun-sik;Lee, Nam-hun
    • The Journal of Internal Korean Medicine
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    • v.43 no.4
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    • pp.625-642
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    • 2022
  • Objectives: Postoperative ileus (POI) is a common impairment of gastrointestinal motility and causes a delay in postoperative recovery, as well as an increased length of hospital stay, but no single strategy has a significant recuperative effect on POI. Studies of traditional Korean medicine (TKM) have reported improvements in bowel function after surgery. The aim of this systematic review was to assess the effectiveness of TKM on postoperative ileus in gastric cancer patients. Methods: We used six databases to search for studies published from January 1, 2007, until May 11, 2022. The included studies were those reporting gastric cancer patients who received TKM treatment after gastrectomy through indicators related to POI. Results: The search identified 27 RCTs that used herbal medicine (Daegeonjung-tang and Gami-leejoongtang), herbal medicine combined with acupuncture (Sama-tang, Gumiseunggi-tang, Daeseunggi-tang, and Insam-tang), acupuncture, acupuncture and moxibustion, electroacupuncture, warm needling, transcutaneous electroacupuncture (TEA), low-frequency electrical acupoint stimulation (LEAS), moxibustion, auricular acupressure, and ST-36 acupoint injection with neostigmine as treatments for POI. The time to first flatus was shortened by herbal medicine combined with warm needling (Sama-tang, Gumiseunggi-tang, Daeseunggi-tang, and Insam-tang), acupuncture, electroacupuncture, warm needling, TEA, moxibustion, auricular acupressure, and ST-36 acupoint injection with neostigmine (p<0.00001). The time to the first defecation decreased significantly in response to the herbal medicine combined with warm needling (Sama-tang, Gumiseunggi-tang, Daeseunggi-tang, and Insam-tang), acupuncture, electroacupuncture, warm needling, TEA, moxibustion, auricular acupressure, and ST-36 acupoint injection with neostigmine (p<0.00001). No serious adverse events occurred. Conclusions: TKM could be a promising option for preventing and resolving POI in gastric cancer patients after gastrectomy.

COMPARISON OF DEMOGRAPHIC, CLINICAL, PSYCHOLOGICAL CHARACTERISTICS BETWEEN CHILDHOOD AND ADOLESCENT-ONSET SCHIZOPHRENIA (소아기 발병 및 청소년기 발병 정신분열병 환아의 인구학적, 임상적, 심리학적인 특성)

  • Chungh Dong-Seon;Lim Myung-Ho;Kim Soo-Kyoung;Jung Gwang-Mo;Hwang Jun-Won;Kim Boong-Nyun;Shin Min Sup;Cho Soo-Churl;Hong Kang-E
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.16 no.2
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    • pp.219-230
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    • 2005
  • Objectives : This study was designed to compare the demographic data, clinical characteristics, developmental delay, and psychological tests between childhood-onset and adolescent-onset schizophrenic in-patients. Methods Medical records of the 17 childhood-onset (very early onset) Schizophrenia and 16 adolescent-onset (early onset) Schizophrenia in-patients were reviewed. Sex, age, psychiatric past history, prodromal symptoms and period, subtype, co-morbid disease, developmental delay, prescribed drug and dosage, treatment response, intelligence quotient (IQ), and Rorschach test were evaluated. Results : The mean admission age of childhood-onset (very early onset) group and adolescent-onset (early onset) group were 12.69$({\pm}2.34)$ and 15.13$({\pm}1.04)$ years. The mean onset age of childhood-onset(very early onset) group and adolescent-onset (early onset) group were 10.79$({\pm}1.95)$ and 14.46$({\pm}0.82)$ years. The mean prodromal period of childhood-onset (very early onset) group and adolescent-onset (early onset) group were 15.94$({\pm}12.33)$ and 8.06$({\pm}6.10)$ month. The time to remission period of childhood-onset (very early onset) group and adolescent-onset (early onset) group were 50.58$({\pm}24.67)$ and 30.06$({\pm}18.04)$ days. Longer time to remission period in childhood-osnet (very early onset) group was associated with earlier age of onset. The mean of total IQ, performance IQ, verbal IQ were at an average level. Discussion : Childhood-onset (very early onset) group and adolescent-onset (early onset) group Schizophrenia had different clinical and psychological features including prodromal period, and IQ subtests.

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A Clinical Review of Primary Tracheal Carcinoma (원발성 악성기관종양의 임상적 고찰)

  • Ryu, Jeong-Seon;Cho, Hyun-Myung;Yang, Dong-Gyoo;Lee, Hong-Lyeol;Kim, Se-Kyu;Chang, Joon;Ahn, Chul-Min;Shin, Kye-Chul;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.4
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    • pp.766-775
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    • 1997
  • Background : Primary malignant tumors of the trachea are extremely rare entities and account for a mere 0.1 per cent of all malignancies of the respiratory tract. Because of vague localizing signs, symptoms and a usually negative routine chest film, the patients with tracheal tumors are often treated for asthma or chronic obstructive pulmonary disease for considerable period of time before correct diagnosis. Method : We have made a review of the 17 cases of primary tracheal tumors in recent 15 years. We reviewed the clinical features including history of smoking and respiratory symptoms, the official readings of initial routine chest film, the cytologic examination of sputum, the time of delay in diagnosis, and the response according to the therapeutic modalities. Results : Eight out of 9 patients with squamous cell carcinoma(SCC) were above 50 years old, five out of 6 patients with adenoid cystic carcinoma(ACC) were below 50 years old. The most common location of primary tracheal tumors was the upper one-third of trachea in 8 cases(47%). The most frequent symptoms were dyspnea in 13/17 cases(76%) and then stridor or wheezing, cough. and sputum in order. The routine chest roentgenographic examinations were not helpful to diagnose tracheal carcinoma and the cytologic examinations of sputums were helpful to diagnose tracheal carcinoma in only one case with adenocarcinoma. The mean times of delay in diagnosis of patients with sec and ACC were 5 months and 24.9 months respectively. We had bronchial asthma in 8 cases(47%) and tracheal tumors in 4 cases(23%) as initial clinical impression. Conclusion : We would like to perform more comprehensive diagnostic tools(high KVP technique, the fibroptic bronchoscopic examination, chest CT scan etc.) in patients who had the suggestive points for the tracheal tumorse(1. unexplained hemoptysis or hoarsness, 2. inspiratory wheezing or stridor, 3. wax and waning of dyspnea according to changes of position, 4. progressive asthmatics unresponsive to antiasthmatic therapy) and radical resection of tumor or external radiation therapy with curative aim as possible.

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Comparison of Several Agronomic Characteristics as Affected by Seeding Dates (파종기 이동이 맥류의 실용적 저형질에 미치는 영향)

  • Hyung-Soo Suh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.26 no.4
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    • pp.298-303
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    • 1981
  • A study was conducted to find out the varietal difference in some important agronomic characters in response to different seeding time in barely from 1975 to 1976 at Chikugo Agric. Expt. Station in Japan. Thirteen varieties which are diverse in growth period were used. Nine seeding time were tried. Seedling emergence, primary tillering, and formation of flower primodia were delayed in proportion to the seeding time. And also heading and maturing time showed the same tendency. This tendency appeared more conspicuous in the late maturing varieties. Therefore, days to heading and maturing duration were inversely shortened by the delay of seeding time and by earliness of variety. Number of spikes as well as culm length and spike length was reduced in the late seeding. Grain yield was reduced in all varieties by late seeding, easpecially with late maturing varieties. In this test, widely adaptable variety to late seeding time was not found, but earliness and high tillering in growth habit appeared more favorable to yield increase.

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The Hospital Life of the Patient with Femoral Neck Fracture (대퇴경부 골절 환자의 입원 생활)

  • Kim, Kyung-Ja;Chi, Sung-Ai
    • Journal of Korean Academy of Nursing Administration
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    • v.2 no.1
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    • pp.35-56
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    • 1996
  • Nowerdays, the increase of traffic accidents and old age population make the Femoral Neck Fracture(FNF) patients increase. By the improvement of education and standard of living the patients demand better medical service than before. This study is designed to give practical help for the FNF patients by observing their hospital life and establish practical nursing strategies for the FNF patients. For these purposes the Ethnographic Participant Observation was adopted. By this study is focused on the hospital life patient's view. For this end, the field study adopted orthopedic ward in the C University Hospital with 400 beds in Seoul. The object patients of the study were twelve patients. The patients experienced five stages : Embarrassment, Conflict, Stability, Independent, and Extension Stage. The findings and prepared nursing strategies are stated as follows. First, in the Embarrassment Stage they suffered embarrassment, anxiety, pain, they could not do ordinary things. The patients who accidental fractures had anxiety from unfamiliar tests and from hospitalization itself. They lamented that they could not ordinary things, and do nothing but obeying the hospital, and endure the pain. They recognized the changed environment and resigned themselves to life in the ward. In this stage, full openness by the nurses is needed. Second, the attribute of the Conflict Stage were conflict, fear, curiosity, belief, reflection. When they sign the consentment form, they experience conflicts about the possibility of complication, fear of recovery from anesthesia, curiosity about the operation procedure, post - operation state, reflection on their past life, and promise to care for their family members after discharge and keep their religious life faithfully. And they accepted the operation depending on God, believing in modern medicine, and the surgeon. Asking for their changed informations, they expected positive results from the operation. In this stage, an empathic attitude by the nurses is needed. Third, the attribute of the Stability Stage were relief, gratitude, difficulty with excretion, and pain. When they awoke from anesthesia, they felt relief because of a the end of the operation, but they experienced extreme pain, difficulty of excretion in bed. They accepted the changed environment and expected recovery. In this stage, support by the nurses is needed. Fourth, the attributes of the Independence Stage were freedom, exercise, nurturing, anxiety, and discomfort. When they ambulated and exercised, they experienced freedom. They showed exhibited weakness of the digestive organs and discomfort hospital's space, structure, and facilities, the delay of medical certificate issue the lack of prompt response by the medical agents. They ate nurturious food and felt anxiety on the end of hospital life and returning to their ordinary life. They showed the independence of overcoming their environment by increasing exercise and expected their discharges. In this stage, respect by the nurses is needed for the patients to, overcome their environment and prepare for their independence. Fifth, the attributes of the Extension Stage were pessimism, isolation, dissatisfaction, and pain. Accompanied injury and old age made their ward life extend to over seven weeks. They exhibited weariness, melancholy, skeptisis, general pessimistic feeling, and desperation caused by their isolated life. They experienced the digestive discomfort caused by the prolonged medication and psycological pain caused by long-time hospitalization. As a, result, their dissatisfaction on the human, physical, and systematic environments had been increased. They acquired critical power and sought for something to do spending their time. They expected vaguely about the returning of their ordinary life. In this stage, counseling is needed by the nurse to overcome positively their psychological, social, and physical problems. The process of the FNF patient's ward life starts from the dependent state, when they are hospitalized, and gradually progresses to self-fulfillment in order to keep independent life. As a result, the FNF patients showed "Response in Challenge" or "Adaptation in Conflict" through their experiences of social, physical, and psychological difficulties.

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Identification and characterization of the MYC2 gene in relation to leaf senescence response in hybrid poplar (Populus alba × P. glandulosa) (현사시나무에서 MYC2 유전자의 분리 및 노화 지연에 관한 특성 구명)

  • Choi, Hyunmo;Bae, Eun-Kyung;Cho, Jin Seong;Lee, Hyoshin;Choi, Young-Im
    • Journal of Plant Biotechnology
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    • v.44 no.4
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    • pp.409-415
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    • 2017
  • The vegetation period of trees might be prolonged by the delay of the leaf senescence in autumn. Thus, we focused on the generation of senescence-delayed transgenic trees to enhance biomass production. The PagMYC2, a gene containing the basic helix-loop-helix domain, was selected as a candidate for a senescence-delayed transgenic tree. The PagMYC2 gene was specifically induced after treatment with phytohormone jasmonic acid, and upregulated by abiotic stresses such as salinity, osmotic pressure and a low temperature. The constitutive overexpression of the PagMYC2 delayed the leaf senescence and inhibited chlorophyll degradation in the transgenic poplars. Leaf senescence analysis was performed in the leaf tissues of the PagMYC2-over-expression transgenic poplars. The transgenic poplars exhibited higher photochemical efficiency than did a wild type plant under a short-day condition (6 hours light/18 hours darkness) or a low temperature condition ($15^{\circ}C$) that was similar to the weather conditions of autumn. These results suggest that the PagMYC2 is a useful genetic resource to improve biomass production, which is able to sustain growth with senescence-delayed leaves for a long time in autumn.

Efficient Parallel Spatial Join Processing Method in a Shared-Nothing Database Cluster System (비공유 공간 클러스터 환경에서 효율적인 병렬 공간 조인 처리 기법)

  • Chung, Warn-Ill;Lee, Chung-Ho;Bae, Hae-Young
    • The KIPS Transactions:PartD
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    • v.10D no.4
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    • pp.591-602
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    • 2003
  • Delay and discontinuance phenomenon of service are cause by sudden increase of the network communication amount and the quantity consumed of resources when Internet users are driven excessively to a conventional single large database sewer. To solve these problems, spatial database cluster consisted of several single nodes on high-speed network to offer high-performance is risen. But, research about spatial join operation that can reduce the performance of whole system in case process at single node is not achieved. So, in this paper, we propose efficient parallel spatial join processing method in a spatial database cluster system that uses data partitions and replications method that considers the characteristics of space data. Since proposed method does not need the creation step and the assignment step of tasks, and does not occur additional message transmission between cluster nodes that appear in existent parallel spatial join method, it shows performance improvement of 23% than the conventional parallel R-tree spatial join for a shared-nothing architecture about expensive spatial join queries. Also, It can minimize the response time to user because it removes redundant refinement operation at each cluster node.

Exogenous Sugars Involvement in Senescence and Ethylene Production of Tree Peony 'Luoyang Hong' Cut Flowers

  • Zhang, Chao;Liu, Miao;Fu, Jianxin;Wang, Yanjie;Li, Dong
    • Horticultural Science & Technology
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    • v.30 no.6
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    • pp.718-724
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    • 2012
  • Sugars play important roles in petal senescence of cut flowers. In the Expt. 1 of this study, the effects of different concentrations of glucose (60, 90, and $120g{\cdot}L^{-1}$) and sucrose (30, 60, and $90g{\cdot}L^{-1}$) application on the vase life, rate of flower diameter increase, rate of flower weight increase and ethylene production of cut tree peony (Paeonia suffruticosa 'Luoyang Hong') were evaluated. At the earlier stage, treatments of different concentrations of glucose and sucrose all retarded the process of flower opening and inhibited the increase of flower diameter and weight, while senescence of flowers fed with different concentrations of glucose was delayed at later stage. Flowers treated with $90g{\cdot}L^{-1}$ glucose displayed the longest vase life, which showed significant difference (P < 0.05) from those of flowers with the control and sucrose treatments. All treatments with glucose or sucrose not only retarded the decrease of flower diameter and weight, but also suppressed the ethylene production at the earlier stage and delayed the peak of ethylene evolution. In order to study the effect of exogenous sugar on the postharvest response of cut tree peony to ethylene, Expt. 2 was conducted. Cut flowers were treated with $90g{\cdot}L^{-1}$ glucose for 4 hours before (GE) or after (EG) exposed to $10{\mu}L{\cdot}L^{-1}$ ethylene for 4 hours. Generally, the opening process of flowers with GE and EG treatments was similar to that of the control, however GE treatment delayed flower senescence. Both GE and EG treatments improved flower diameter and weight, and GE treatment delayed the time of flower weight decrease. Besides, GE delayed climacteric ethylene evolution for 8 hours. All above suggest that exogenous sugars delay tree peony 'Luoyang Hong' cut flower senescence and extend flower vase life through their roles in the decrease of water loss and the suppression of sensitivity to ethylene and ethylene production.