• Title/Summary/Keyword: 환기저하

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Transformer Based Deep Learning Techniques for HVAC System Anomaly Detection (HVAC 시스템의 이상 탐지를 위한 Transformer 기반 딥러닝 기법)

  • Changjoon Park;Junhwi Park;Namjung Kim;Jaehyun Lee;Jeonghwan Gwak
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2024.01a
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    • pp.47-48
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    • 2024
  • Heating, Ventilating, and Air Conditioning(HVAC) 시스템은 난방(Heating), 환기(Ventilating), 공기조화(Air Conditioning)를 제공하는 공조시스템으로, 실내 환경의 온도, 습도 조절 및 지속적인 순환 및 여과를 통해 실내 공기 질을 개선한다. 이러한 HVAC 시스템에 이상이 생기는 경우 공기 여과율이 낮아지며, COVID-19와 같은 법정 감염병 예방에 취약해진다. 또한 장비의 과부하를 유발하여, 시스템의 효율성 저하 및 에너지 낭비를 불러올 수 있다. 따라서 본 논문에서는 HVAC 시스템의 이상 탐지 및 조기 조치를 위한 Transformer 기반 이상 탐지 기법의 적용을 제안한다. Transformer는 기존 시계열 데이터 처리를 위한 기법인 Recurrent Neural Network(RNN)기반 모델의 구조적 한계점을 극복함에 따라 Long Term Dependency 문제를 해결하고, 병렬처리를 통해 효율적인 Feature 추출이 가능하다. Transformer 모델이 HVAC 시스템의 이상 탐지에서 RNN 기반의 비교군 모델보다 약 1.31%의 향상을 보이며, Transformer 모델을 통한 HVAC의 이상 탐지에 효율적임을 확인하였다.

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Oxygen Desaturation during Nutritive Sucking in Premature Infants with Bronchopulmonary Dysplasia : Its Effect on Feeding and Growth until 4 Months of Corrected Age (기관지폐 형성이상 미숙아의 젖병수유 시 저산소증: 생후 4개월까지 수유상태 및 성장에 미치는 영향)

  • Lim, Chang-Hwan;Lee, Joo-Young;Lee, Hyun-Seung;Lee, Jung-Hyun;Kim, So-Young;Sung, In-Kyung;Chun, Chung-Sik
    • Neonatal Medicine
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    • v.15 no.2
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    • pp.134-141
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    • 2008
  • Purpose : This study examined the occurrence of oxygen desaturation events during nutritive sucking in premature infants with bronchopulmonary dysplasia (BPD) and its effects on feeding and growth outcomes until 4 months of corrected age (CA). Methods : Thirty-four premature infants with BPD free from major cardiac, gastrointestinal, respiratory anomalies were included. By reviewing medical records, clinical characteristics, feeding conditions at 36 weeks of postmenstrual age (PMA), we focused on oxygen desaturation, and short-term outcomes in 14 infants with no or mild desaturation (group A) and in 20 infants with moderate or severe desaturation (group B). Results : Group B had lower birth weight and shorter gestational age at birth, longer duration of hospitalization, was discharged at higher weeks of PMA, and needed ventilatory assist and oxygen supplementation longer than group A (P<0.05). Group B started nutritive sucking later, with a greater decrease in $SpO_2$ during sucking, being more indicative of feeding problems at 40 weeks of PMA, but not at 4 months of CA. Percent of infant needing oxygen supplementation and percent of infants with growth failure were not different between groups at 40 weeks of PMA and 4 months of CA. Body weight and growth velocity differences noted at 40 weeks of PMA became insignificant at 4 months of CA. Conclusion : The severity of desaturation during nutritive sucking in premature infants with BPD influenced the infant's feeding and growth at 40 weeks of PMA. However, it disappeared at 4 months of CA.

Usability Test and Investigation of Improvements of the ECDIS (ECDIS의 사용성 평가 및 개선사항 분석)

  • Lee, Bo-Kyeong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.2
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    • pp.146-156
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    • 2018
  • The ship's chart system was changed from the use of paper chart to the ENC (Electronic Navigational Chart) using ECDIS (Electronic Chart Display and Information System). The introduction of ENC in ships is necessary for ship automation and for the digitalizing of data and integration of information, but unexpected various problems have occurred and are posing a great threat to safe navigation in the transitional period when the new system has been applied to the sea. In this paper, to assess whether ECDIS contributes to the safety of navigation for its intended purposes as new navigation equipment, a usability test of ECDIS was conducted on masters and crew who have used ECDIS on ocean-going vessels. The result was verified with a paired sample T-test, and it was significantly analyzed with the effectiveness of a simplified task; cost efficiency was decreased since ECDIS was used. By analyzing 'MSC.1/Circ.1503 ECDIS - Guidance for good practice', we found that the effects of the maintenance of ECDIS software, operating anomalies identified within ECDIS, differences between raster chart display system (RCDS) and ECDIS, and matters of identification were compounded by the overlapping information on the safety of ships. The anomalies were also grouped according to their characteristics, and we proposed suitable improvements accordingly. The reason for the reduction in efficiency in the usability test was that the problems with ECDIS were intended to be solved only with the careful use of navigational officers who did not have systematic solutions. To solve these problems, the maintenance of software, the improvement of ECDIS anomalies, the reliable ENC issuance including the global oceans, and S-mode development are a priority.

Video-Assisted Thoracic Surgery Under Epidural Anesthesia -in High-Risk Group (경막외마취하에 비디오 흉강경수술 - 고위험군에서)

  • Lee, Song-Am;Kim, Kwang-Taik;Kim, Il-Hyeon;Park, Sung-Min;Baek, Man-Jong;Sun, Kyung;Kim, Hyoung-Mook;Lee, In-Sung
    • Journal of Chest Surgery
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    • v.32 no.8
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    • pp.732-738
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    • 1999
  • Background: Video-assisted thoracoscopic surgery has become a standard therapy for several diseases such as pneumothorax, hyperhidrosis, mediastinal mass, and so on. These methods usually required single-lung ventilation with double-lumen endobronchial tube to collapse the lung under general anesthesia. However, risks of general anesthesia itself and single-lung ventilation must be considered in high-risk patients. Material and method: Between December 1997 and July 1998, eight high-risk patients (6: empyema, 1: intractable pleural effusion, 1: idiopathic pulmonary fibrosis) with underlying pulmonary disease and poor general condition were treated by video-assisted thoracoscopic surgerys under epidural anesthesia and spontaneous breathing. Result: Video-assisted thoracoscopic surgerys were successfully per formed in 7 patients. Conversion to general anesthesia was required in 1 patient because of decrease in spontaneous breathing. But, conversion to open decortication was not required. In two patients with chronic empyema, one patient required thoracoplasty as a second procedure and one patient required re-video-assisted thoracoscopic procedure due to a recurrence. The mean operative time was 31.8$\pm$15.2 minutes. No significant postoperative respiratory com plication was encountered. Conclusion: Video-assisted thoracoscopic surgerys can be per formed safely under epidural anesthesia for the treatment of empyema and diagnosis of pulmonary abnormalities in high-risk patients.

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A Study on Reducing Method for Stack Effect in High-rise Building (고층 건축물 연돌효과 저감 방법에 대한 연구)

  • Kim, Jin Soo
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.66-66
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    • 2011
  • 중위도 이북의 건물에서 고층건물의 혹한기 연돌효과는 건물의 여러 가지 기능에 큰 영향을 미치며, 승강기 승강로는 화재시 차압 때문에 연기의 주된 전파통로가 된다. 외피의 밀폐성능을 높여 건물 내부의 연도효과를 줄일 수 있으나, 외피의 밀폐기능은 비상시 피난을 위해 피난경로를 개방하는 순간 일시에 무력화된다. 또한 건물 외피의 밀폐성능이 우수할수록 연돌효과 그 자체로써 건물외피에 미치는 구조적 영향이 커진다. 고층부의 연돌효과는 외피를 밖으로 밀어내는 작용이므로 풍하측에서는 마이너스 풍압에 더하여 건물 외피에 부담을 증가시킨다. 그러므로 고층건물에 발생하는 혹한기 연돌효과의 영향을 정리하자면 다음과 같다. ${\bullet}$ 건물 외벽 및 창문에 미치는 구조적 영향 ${\bullet}$ 제연 시스템의 기능 저해 ${\bullet}$ 승강기 문 개폐 장애와 소음 등 설비 기능의 부정적 영향 ${\bullet}$ 공조기능 장애 ${\bullet}$ 화재시 승강기 승강로 등 수직 샤프트를 통한 연기 전파 혹한기 건물 안팎의 온도차가 40K일 때 높이 600m인 초고층 건물 최상층에 발생하는 연돌효과에 의한 차압은 풍속으로 환산할 때 32m/s에 달한다. 그러므로 초고층 건물 설계시에는 최상층의 풍하측에 설계상의 예상 최대풍속에다 이러한 환산풍속을 더한 고속 풍력이 창문을 밖으로 밀어내는 것으로 보아야 한다. 또한 공조 및 환기시스템에서는 이러한 차압을 고려하지 않으면 고층부에서 환기 성능이 무력화될 수 있다. 다음과 같은 방법들을 이용하여 고층건물의 연돌효과를 효과적으로 줄일 수 있다. 1) 계단실의 연돌효과 저감 방법 계단실에 발생하는 연돌효과에 의한 차압은 계단실에 상승기류를 발생시킨다. 이러한 차압과 상승기류는 계단실 상하부를 개방하면 자연적으로 평형을 이루게 되므로 별도의 제어가 필요 없게 된다. 또한 화재감지기와 연동하여 상하부 외벽의 개구부를 열어두게 되면 피난상황에 따라 문이 여닫힘으로써 발생하는 압력상태의 변화를 고려할 필요가 없게 된다. 2) 승강기 승강로의 연돌효과 승강로의 상하부에 대규모 개구를 두면 대규모의 외기가 도입되어 상승 유동 후 배출되므로 승강로 내부 온도 저하로 연돌효과가 저감되고, 승강로로 유입된 연기는 대규모의 외기에 희석되어 농도가 낮아지고 대부분 외부로 배출된다. 3) 샤프트 복합효과를 이용하는 방법 거실 평면적에 비해 승강기나 계단이 아주 많고 누설틈새 등 개구의 면적 합계가 크면 샤프트들이 서로 복합효과를 이루어 연돌효과에 의한 차압이 줄어든다. 연돌효과 제어용 샤프트를 하나 더 보조적으로 설치함으로써, 보조샤프트에 의해 발생하는 차압으로 거실을 가압 혹은 감압하여 문제가 되는 차압을 어느 정도 상쇄할 수 있다.

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Blood Gas Analysis of Respiratory Depression during Sevoflurane Inhalation Induction for General Anesthesia in the Disabled Patients (장애 환자의 전신 마취를 위한 세보플루란 흡입 유도 시 발생한 호흡 저하의 혈액 가스 분석)

  • Yoon, Taewan;Kim, Seungoh
    • Journal of the korean academy of Pediatric Dentistry
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    • v.45 no.4
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    • pp.508-513
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    • 2018
  • Tidal volume by sevoflurane in small amounts is stable due to the increase in the breathing rate. But alveolus ventilation decreases due to sevoflurane as the degree of sedation increases; this ultimately causes $PaCO_2$ to rise. The occurrence of suppression of breath increases the risk of severe hypoxia and hypercapnia in deeply sedated patients with disabilities. Sevoflurane inhalation anesthesia has a number of risks and may have unexpected problems with hemodynamic changes depending on the underlying state of the body. This study was conducted to examine the stability of internal acid-base system caused by respiratory depression occurring when patients with disabilities are induced by sevoflurane. Anesthetic induction was carried out by placing a mask on top of the patient's face and through voluntary breathing with 4 vol% of sevoflurane, 4 L/min of nitrous oxide, and 4 L/min of oxygen. After the patient's loss of consciousness and muscle relaxation, IV line was inserted by an expert and intravenous blood gas was analyzed by extracting blood from vein. In a deeply sedated state, the average amount of pH of the entire patients was measured as $7.36{\pm}0.06$. The average amount of $PvCO_2$ of the entire patients was measured as $48.8{\pm}8.50mmHg$. The average amount of $HCO_3{^-}$ of the entire patients was measured as $27.2{\pm}3.0mmol/L$. In conclusion, in dental treatment of patients with disabilities, the internal acid base response to inhalation sedation using sevoflurane is relatively stable.

Behavioral Variant Frontotemporal Dementia Phenocopy Syndrome (행동증상 아형 전측두엽 치매 표현형모사 증후군)

  • Cheon, Jin Sook
    • Korean Journal of Psychosomatic Medicine
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    • v.25 no.1
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    • pp.3-11
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    • 2017
  • Objectives : The aim of this study was to draw attention toward so called 'behavioral variant frontotemporal dementia(bvFTD) phenocopy syndrome', which is difficult to discriminate with the primary psychiatric disorders, showing poor response to conventional therapeutic drugs, leading to higher risk to misdiagnoses and legal problems. Furthermore, the author insisted that our interest and study on them must be continued. Methods : English articles published during 2000 thru 2016 had been searched by internet with the combination of words such as 'frontotemporal', 'phenocopy' and 'behavioral', and reviewed. Besides, two clinical vignettes were described. Results : Precise diagnosis is important because patients' behavioral symptoms can influence on their families and community. However, disease-modifying treatment for bvFTD are not developed until now, and recent therapeutic drugs are only good for specific symptoms, while deterioration progresses in spite of proper psychiatric management. The possible bvFTD patients are not progressed into probable bvFTD clinically, showing no decline of cogntive and social function, no decrease of activity function, longer survival time, and normal neuroimaging for several years. Conclusions : Rather than expected, there are much more patients having clinical symptoms, course and diagnostic findings including neuroimaging, which are atypical to classical frontotemporal dementia and primary psychiatric disorders. If our knowledge and discriminating ability is improved, discovery rate of that cases will be increased. However, the identity of these atypical features are not clarified until now, it must be further actively investigated.

Risk Factors of Primary Lung Cancer and Spirometry (원발성 폐암의 위험인자와 폐활량 측정)

  • Rhee, Yang-Keun;Hwang, Keum-Man;Lee, Yong-Chul
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.6
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    • pp.646-652
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    • 1993
  • Background: Lung cancer and chronic obstructive lung disease often coexist in the same person who are elderly and cigarette smoking. There are several reports that the presence of chronic obstructive pulmonary disease constitutes an independent risk factor for the development of lung cancer. Moreover, the association between mucus hypersecrtion and lung cacer has been reported. Method: In 72 cases with primary lung cancer which were confirmed histopathologically at Chonbuk University Hospital from August 1986 to July 1991, We evaluated the relationship between spirometry and lung cancer characteristics. Results: Six cases(8.3%) showed normal lung function, 16(22.2%) cases showed pure restrictive lung disease, 46(63.9%) cases showed moderated obstructive lung disease and 4(5.6%) cases showed severe obstructive lung disease. $FEV_1$(%) was lower in central type than in peripheral type, lower in advanced non-small cell cancer and lower in subjects with phlegm. $FEV_1$/FVC(%) was higher in small cell cancer than in squamous cell cancer and higher in patients without previous pulmonary disease than with previous pulmonary disease. But there was no statistically significant difference in lung function according to histologic types and smoking history. Lung cancers with $FEV_1$/FVC less than 75% consisted of 35 cases of squamous cell cancer, 7 of small cell cancer(14%), 5 of adenocarcinoma(10%), 2 of large-cell carcinoma and 1 of unclassified carcinoma. Squamous cell carcinoma occured more in patients with $FEV_1$/FVC<75% than with $FEV_1$/FVC$\geq$75%(p<0.05). Conclusion: It was suggest that low $FEV_1$/FVC, as reflection of obstructive lung disease, may be at greater risk for squamous cell carcinoma in cigarette smoker.

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Cultural characteristics of new oyster mushroom variety "Cheongsan" (느타리 신품종 "청산"의 재배 특성)

  • Lee, Kwang-Jae;Park, Young-Hak;Cho, Byung-Ju;Lee, Byung-Ryong;Joo, Jin-Ho;Park, Dong-Sik;Kim, Kyoung-Hee
    • Journal of Mushroom
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    • v.5 no.1
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    • pp.21-24
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    • 2007
  • A new variety of oyster mushroom 'Choengsan' was developed with crossing between monokaryotic strains derived from Suhan and Wonhyoung #3. It was developed by Agriproduct Processing Experiment Station, Gangwon Agricultural Research & Extension Services in 2006. The optimum temperature of mycelial growth was around $27{\sim}28^{\circ}C$ and that of fruiting body was $14{\sim}17^{\circ}C$. The color of pileus was dark-gray color. The period of primordial occurrence was about 20 days in bed cultivation using cotton waste and the yields were $38kg/3.3m^2$.

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The Influences of Immune Function and Respiratory System on Aerobic Exercise by Exposed Acute Hypobaric Hypoxic Environment. (급성 저압.저산소 노출에서의 유산소성 운동이 면역기능 및 호흡기계에 미치는 영향)

  • Lee, Dong-Jun
    • Journal of Life Science
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    • v.19 no.6
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    • pp.825-831
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    • 2009
  • The purpose of this study was to investigate the influences of immune function and respiratory system on aerobic exercise of 75 %HRmax intensity in an exposed acute hypobaric hypoxic environment. The subjects were 20 male college students, 10 of which were soccer players (19.6${\pm}$0.8 yr, BMI 22.3${\pm}$1.0, V02max 56.5${\pm}$4.8 mljkgjmin) and 10 general students (22.2${\pm}$2.3 yr, BMI 22.7${\pm}$2.1, $VO_{2max}$ 50.5${\pm}$6.6 ml/kg/min). Items of measurement after exercise on level and high altitude were $O_{2}$, $CO_{2}$, ventilation (VE), respiratory frequency, respiratory quotient, RBC, MCV, MCH, MCHC, Hb, Hct, reticulocyte, WBC, neutrophil, lymphocyte, monocyte, basophil, and immunoglobulin (IgA, IgD, IgG, IgM). As the result of the verifying hypothesis, these results may suggest three new findings: first, to produce hypoxic ventilatory depression not only at level land but also at 3,000 m high altitude during 30 minute aerobics exercise of 75 %HRmax intensity, second to be more excellent for soccer players in adaptation and sensibility on response of respiratory system at high altitude, and third, to change each other by regular exercise habits or altitude in the monocyte.