• 제목/요약/키워드: Total head

검색결과 1,882건 처리시간 0.024초

임펠러 가공량에 따른 펌프성능의 해석적 연구 (A Study on the Pump Performance Analysis by Modifying the Impeller for a Seawater Pump using CFD)

  • 장영기;송우석
    • 한국압력기기공학회 논문집
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    • 제8권3호
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    • pp.23-27
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    • 2012
  • A seawater pumps in the nuclear power plant is responsible for providing cooling water to other components all the time. Because of the depreciation, the seawater pump with current impeller consumes too much power for maintaining the total head. Therefore the objective of this study is to reduce power with maintaining certain the total head by cutting the current impeller. By using a commercial CFD code, FLUENT, the overall performance of seawater pump with current and modified impeller was simulated. Also Affinity law was applied at pumps with various impeller diameter and evaluated the validity of the affinity law. The numerical results show that the pump efficiency is quite irrelevant to the diameters of the impellers and the pump efficiency becomes worse over the designed flow rate. And affinity law result and numerical one show good agreements at small change of impeller diameter. One of the impeller diameters was decided to modify and was applied to the nuclear power plant with the numerical study above.

호흡방법에 따른 전방머리자세의 목근육 활성도 변화 (Effects of Breathing Methods on Neck Muscle Activation in Subjects with a Forward Head Posture)

  • 배원식;이현옥;박두진
    • PNF and Movement
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    • 제15권2호
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    • pp.159-166
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    • 2017
  • Purpose: This study attempts to determine the effects of applying three kinds of breathing exercises for four weeks on the neck muscle activation of subjects with a forward head posture. Methods: A total of 30 adults aged in their twenties (15 men and 15 women) with a forward head posture who voluntarily agreed to participate after listening to the purpose and procedure of this research were chosen as the subjects of this study. The subjects were randomly divided into either the diaphragmatic breathing exercise (DBE) group, the abdominal drawing-in maneuver (ADIM) group, or the abdominal expansion method (AEM) group according to the breathing intervention scheme. Each group included ten subjects. The muscle activity of the sternocleidomastoid, scalenus anterior, and splenius capitis was measured in all the groups prior to the intervention, two weeks after the intervention, and four weeks after the intervention. All the interventions were implemented for 30 minutes a day, three times a week, for a total of four weeks. Results: No significant between-group difference was observed in terms of the change in neck muscle activity according to the four-week intervention scheme. Further, there was no interaction between the intervention period and the intervention scheme in relation to the change in neck muscle activity. Conclusion: The results of this study suggest that abdominal expansion exercise is as effective as other breathing exercise methods for subjects with a forward head posture. We therefore expect that abdominal expansion exercise can be used as a scheme for the prevention of symptoms as well as therapy for patients with a forward head posture.

양식 민어의 두부형질에 의한 전장 예측 (Total Length Estimation from Head Dimensions of Artificially Propagated Brown Croaker Miichthys miiuy)

  • 박인석;김영자;최희정;오승용;노충환;이승환
    • 한국어류학회지
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    • 제19권2호
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    • pp.128-131
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    • 2007
  • 전장 3.0~650.0 mm의 민어, Miichthys miiuy 209 개체의 두장, 문장, 안와후연장 및 안경을 계측하였다. 측정된 개체들의 모든 두부형질은 전장에 대해 회귀하였고, 머리의 상대크기에 선형으로 증가하였다. 결정계수($r^2$)는 0.9823~0.9916의 범위를 나타내었고, 모두 유의하게 나타났다(P<0.0001). 본 연구에서 사용된 두부형질들은 민어의 성공적인 사육을 위한 개체 및 집단성장사 및 형태 변형을 감지할 수 있는 유용한 지표가 될 수 있으리라 사료된다.

기관전진피판술을 이용한 영구기관 개구협착의 치료 (Management of Permanent Tracheostomal Stenosis by Tracheal Advancement Flap)

  • 최종욱;민헌기;최건;정광윤;김영호;박찬;이병기
    • 대한기관식도과학회지
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    • 제1권1호
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    • pp.136-141
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    • 1995
  • Tracheostomal stenosis after total laryngectomy is a distressing complication which con-tributes significantly to both psychosocial and physical morbidity according to nature and severity in laryngectomee. Sternal stenosis will compromise not only optimal air exchange, crust formation but also the ability to clear tracheobronchial secretion, so pneumonia and atelectasis will develop. Having a number of procedure recommended for correction of such stenosis with limited results. We developed new technique which is based on tracheal advancement flap had been ap-plied to 12 patients, successfully. We think that total or partial tracheal advancement flap technique Is useful for widening the stoma and advantages of this method are following. 1. Simple technique. possible under local anesthesia 2. Healthy tracheal ring facilities width control 3. Less chance of refractory scar stenosis 4. Tracheoesophageal shunt can be constructed after the partial advancement flap.

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이하선 샘암종의 재발로 오인된 지선암 1예 (A Case of Carcinoma with Sebaceous Differentiation arising in the Patient who was Treated with Parotid Gland Adenocarcinoma)

  • 박솔;윤주현;고유진;정수연
    • 대한두경부종양학회지
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    • 제38권1호
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    • pp.37-41
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    • 2022
  • Sebaceous carcinoma is extremely rare in the parotid gland. Recently, we experienced a case of carcinoma with sebaceous differentiation arising from the parotid gland in patient who was diagnosed as parotid adenoma carcinoma and underwent total parotidectomy. A 73-year-old male visited our department for the evaluation of 3-month history of infra-auricular mass combined with pain. Radiologic finding showed lobulated enhancing and solid mass with calcification in the right parotid gland. Initially, total parotidectomy with supraomohyoid neck dissection was performed. Pathological findings showed capsulated whitish mass with hemorrhage and cystic degeneration. Immunohistochemically, CK7, CK5/6, p63 were positive and CEA was negative. The intra-operative frozen section diagnosis was mucoepidermoid carcinoma. The permanent diagnosis was changed to adenocarcinoma, NOS(not otherwise specified). Fourteen months later, the newly developed mass was noticed on the operation bed. The mass was clinically diagnosed as recurred adenocarcinoma. Revision parotidectomy was performed and pathological findings revealed that the tumor was newly developed sebaceous carcinoma. We report a case of carcinoma with sebaceous differentiation in parotid gland with a review of literature.

Prevalence of head louse infestation among primary schoolchildren in the Republic of Korea: nationwide observation of trends in 2011-2019

  • Seungwan Ryoo;Sooji Hong;Taehee Chang;Hyejoo Shin;Jae Young Park;Jeonggyu Lee;Eun-Hee Nah;Eun Hee Lee;Bong-Kwang Jung;Jong-Yil Chai
    • Parasites, Hosts and Diseases
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    • 제61권1호
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    • pp.53-59
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    • 2023
  • Head louse infestation is a significant public health problem across the world, particularly among preschool and primary schoolchildren. This study investigated the trends of head louse infestation in the Republic of Korea over a 9-year period (2011-2019), targeting primary schoolchildren in 3 areas of Seoul, 4 other large cities, and 9 provinces. A survey was administered annually by the health staff of each regional office (n= 16) of the Korea Association of Health Promotion (KAHP). The branch offices of KAHP examined a total of 51,508 primary schoolchildren, comprising 26,532 boys and 24,976 girls. Over the 9-year survey, a total of 1,107 (2.1%) schoolchildren tested positive for adults and/or nits of Pediculus humanus capitis. The prevalence was 2.8% (133/4,727) in 2011-2012 and gradually decreased to 0.8% (49/6,461) in 2019 (P< 0.05). Head lice were found more frequently in girls (3.0%; 746/24,976) than in boys (1.4%; 361/26,532) (P< 0.05). In terms of geographic localities, the highest infestation rate, 4.7% (average prevalence over 9 years), was observed in southern Seoul (Gangnam branch of KAHP), whereas the lowest infestation rate, 0.7%, was seen in Gyeongsang (north and south provinces) and western Seoul. Although the prevalence decreased significantly during the 9-year period, head louse infestation remains a health and hygiene issue among primary schoolchildren in the Republic of Korea. Regular surveys along with health education are needed to further improve children's hair hygiene.

후두전적출술 후 기공주변의 재발 (Stomal Recurrence after Total Laryngectomy - A Critical Analysis of Etiology and Therapeutic Problems­)

  • 최종욱;정광윤;오재훈;김용환;김병훈
    • 대한두경부종양학회지
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    • 제10권2호
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    • pp.152-156
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    • 1994
  • 최근 10년간 후두전적출술을 시행하였던 159례 중 기공주변 재발이 발생하였던 12례에 대하여 후향적으로 분석함으로써 다음과 같은 결과를 얻었다. 1) 기공주변의 재발은 1차 치료종결후 평균 8.23개월에 발견되었으며, 발생빈도는 7.55%이었다. 2) 추정 원인은 광범위한 원발병소로 인한 부적절한 절재연, 기관절개술후 근치수술의 지연, 불완전한 림프전이절의 처리 순이었다. 3) 7례는 항암화학요법(국소 또는 전신적)과 고식적 방사선요법을 시행하였으며, 5례는 구제수술을 시행한 후 고식적 방사선요법 및 항암화학요법을 시행하였으나 구제수술을 받은 제 1형 1례를 제외하고는 모두 사망하였으며, 평균 생존기간은 $7.32{\pm}5.61$개월 이었다. 이상의 성적에서 기공주변의 재발 가능성이 높은 고위험군에 대하여는 광범위한 절제 후 적극적인 추적관찰과 더불어 과감한 구제수술로 생존기간을 연장할 수 있을 것으로 생각되었다.

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두경부암 환자의 대체요법 이용 실태 (Complementary and Alternative Medicine in the Patients with Head and Neck Cancer)

  • 김광현;정은정;하정훈;권성근;성명훈
    • 대한두경부종양학회지
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    • 제21권1호
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    • pp.21-25
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    • 2005
  • Background and Objectives: The popularity of complementary and alternative medicine(CAM) has grown at an astonishing rate in recent years. Because patients are interested in CAM and want to use it, physicians also should be concerned about CAM and know about the current situation of its usage. In this study, we tried to determine the prevalence of CAM use in the patients with head and neck cancer and correlate with demographics and tumor characteristics. Materials and Methods: A total of 87 patients with head and neck cancer previously treated with surgery at Seoul National University Hospital from March through June, 2004 were enrolled in this study. The patients were completed, questionnaire about the use of CAM and demographic information. Tumor characteristics were obtained from the patient's medical records. Results: Of the 87 patients, 33 patients(37.9%) use at least one CAM. There was no statistically significant correlation between patient's data and prevalence of CAM use. Of those patients using CAM, 16(48.5%) of 33 were using 2 or more therapies. The majority of agents used by patients in this study are mushrooms such as Phellinus and Reishi, followed by dietary therapy. A majority(60.6%) of patients were introduced to alternative medicine by friends or family members. Conclusion: Considerable cancer patients use CAM. Head and neck oncologists should inform themselves about CAM to counsel and educate the patients. Further scientific investigations on promising CAM agents may help advance cancer treatment.

무선 센서 네트워크에서의 에너지 효율적인 클러스터 헤드 선출 알고리즘 (ECS : Energy efficient Cluster-head Selection algorithm in Wireless Sensor Network)

  • 최경진;윤명준;심인보;이재용
    • 한국통신학회논문지
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    • 제32권6B호
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    • pp.342-349
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    • 2007
  • 무선 센서 네트워크에서 클러스터링은 클러스터 헤드(cluster head) 노드가 클러스터 멤버 노드의 데이터를 병합(aggreation)하여 싱크(Sink)로 전송함으로써 노드 간 통신의 양을 줄이게 하고 클러스터 내부적으로는 TDMA 스케줄에 기반하여 클러스터 헤드가 클러스터 멤버 노드의 스케줄을 조정함으로써 노드의 슬립타임을 연장하게 한다. 제안하는 ECS(Energy efficient Cluster-head Selection) 알고리즘은 에너지가 제한되는 센서 네트워크의 수명 향상을 위하여 노드 자신의 요소(factor) 즉, 자신의 초기 에너지 및 현재 에너지, 클러스터 헤드에 의해 병합된 클러스터 내 노드들의 데이터가 싱크로 전송되는 각 라운드, 노드 자신이 클러스터 헤드로 선출(selection) 된 수를 이용하여 확률적인 방법으로 클러스터 헤드를 자가 선출한다.

농촌지역에서의 두부외상 환자의 임상경험 (Clinical Experience of Head-Injured Patients in the Rural Area)

  • 김일만
    • Journal of Korean Neurosurgical Society
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    • 제29권8호
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    • pp.1050-1054
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    • 2000
  • Objective : The incidence of head injury has been increasing in the rural area. The author investigated the clinical features and difficulties in care of the acute head-injured patients in this area. Method and Material : The authors performed a retrospective review of radiological data and clinical records in patients with mild to moderate head injury. Cause, type of craniocerebral injury, delayed intracranial lesions, complications, its relation to alcohol abuse, and outcome were analyzed. Results : In total of 68 cases, 20(29.4%) victims were associated with acute alcohol intoxication. Motor vehicle accident was the leading cause of head injury and the most common craniocerebral lesion was basilar skull fracture. Eight(11.8%) patients showed delayed radiological and clinical deterioration and 40(58.8%) were followed-up regularly after discharge. The subdural hygroma was commonly noted in the elderly and alcoholics. Causes of thirty events that resulted in an atypical and difficult neurosurgical practice were as follows : delayed admission, premature discharge against doctor's request, refusal of radiological studies and admission, misunderstanding of disease entity, and unreasonable desire of transfer to tertiary hospitals. Inaccurate initial diagnoses were made by emergency doctors in twenty patients. During the course of treatment, there were a few complications such as alcohol withdrawal, acute otitis media, cerebrospinal fistula, facial weakness, and posttraumatic seizure. Outcome was good in 60(88.2%) patients. Conclusion : Most of minor head trauma patients in this series have shown good results, but we have to consider some possible complications and delayed intracranial lesions in these patients that should be managed with special cautions with various kinds of treatment difficulties.

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