• Title/Summary/Keyword: 기계적 장애

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Root Morphology of Norway Spruce (Picea abies [L.] Karst.) in the Differently Acidified Forest Soils (토양(土壤) 산성화(酸性化) 정도(程度)에 따른 독일가문비나무(Picea abies [L.] Karst.))

  • Lee, Do-Hyung
    • Journal of Korean Society of Forest Science
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    • v.89 no.5
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    • pp.677-684
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    • 2000
  • This study was conducted to investigate the relationship of development of root and soil condition and also to elucidate the difference between stands for mechanical and physical stability according to distribution of roots in the Norway Spruce (Picea abies [L.] Karst.) stands of 30 to 40 year of ages with different soil condition. In the root structure, remarkably different root pattern was shown among the three stands; Eberg$\ddot{o}$tzen stand showed large number f roots with much fine roots which deeply in vertical direction while Barbis stands had thicker root and small number of root than Eberg$\ddot{o}$tzen stand. The Weidenbrunnen stand showed differently half-vertical and plate root structure and the root developed not to be deeply compared to the other two stands. In the total number of root, Eberg$\ddot{o}$tzen stand had the most number of 74 and Barbis stand 33, Weidenbrunnen stand 57 respectively. Eberg$\ddot{o}$tzen stand had much more number of vertical root with 57 than the other two stand; Barbis 21 and Weidenbrunnen 36. In the total length of root, Weidenbrunnen stand showed to be longer than the other two stands and the length of horizontal root also showed longer. Regarding to the rates of horizontal root against vertical root, Eberg$\ddot{o}$tzen stand showed comparatively higher value as 1,2 than other two stands(0.5). In the total weight of root, Weidenbrunnen stand showed very high value compared with the other stands and ratio of vertical root against horizontal root was 0,16 which is very lower than the other two stands(0,4). The remarkable differences of root pattern of Norway spruce stands appeared in this study are through to be caused more by chemical property of soil such as acidity den the mechanical or physical factor of soil conditions.

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Development of the IRIS Collimator for the Portable Radiation Detector and Its Performance Evaluation Using the MCNP Code (IRIS형 방사선검출기 콜리메이터 제작 및 MCNP 코드를 이용한 성능평가)

  • Ji, Young-Yong;Chung, Kun Ho;Lee, Wanno;Choi, Sang-Do;Kim, Change-Jong;Kang, Mun Ja;Park, Sang Tae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.1
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    • pp.55-61
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    • 2015
  • When a radiation detector is applied to the measurement of the radioactivity of high-level of radioactive materials or the rapid response to the nuclear accident, several collimators with the different inner radii should be prepared according to the level of dose rate. This makes the in-situ measurement impractical, because of the heavy weight of the collimator. In this study, an IRIS collimator was developed so as to have a function of controlling the inner radius, with the same method used in optical camera, to vary the attenuation ratio of radiation. The shutter was made to have the double tungsten layers with different phase angles to prevent the radiation from penetrating owing to the mechanical tolerance. The performance evaluation through the MCNP code was conducted by calculating the attenuation ratio according to the inner radius of the collimator. The attenuation ratio was marked on the outer scale ring of the collimator. It is expected that when a radiation detector with the IRIS collimator is used for the in-situ measurement, it can change the attenuation ratio of the incident photon to the detector without replacing the collimator.

Development of an Intelligent Legged Walking Rehabilitation Robot (지능적 족형 보행 재활 보조 로봇의 개발)

  • Kim, Hyun;Kim, Jung-Yup
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.9
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    • pp.825-837
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    • 2017
  • This paper describes a novel type of a walking rehabilitation robot that applies robot technologies to crutches used by patients with walking difficulties in the lower body. The primary features of the developed robot are divided into three parts. First, the developed robot is worn on the patient's chest, as opposed to the conventional elbow crutch that is attached to the forearm; hence, it can effectively disperse the patient's weight throughout the width of the chest, and eliminate the concentrated load at the elbow. Furthermore, it allows free arm motion during walking. Second, the developed robot can recognize the walking intention of the patient from the magnitude and direction of the ground reactive forces. This is done using three-axis force sensors attached to the feet of the robot. Third, the robot can perform a stair walking function, which can change vertical movement trajectories in order to step up and down a single stair according to the floor height. Consequently, we experimentally showed that the developed robot can effectively perform walking rehabilitation assistance by perceiving the walking intention of the patient. Moreover we quantitatively verified muscle power assistance by measuring the electromyography (EMG) signals of the muscles of the lower limb.

A Pattern Recognition Method of Fatigue Crack Growth on Metal using Acoustic Emission (음향방출을 이용한 금속의 피로 균열성장 패턴인식 기법)

  • Lee, Soo-Ill;Lee, Jong-Seok;Min, Hwang-Ki;Park, Cheol-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.3
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    • pp.125-137
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    • 2009
  • Acoustic emission-based techniques are being used for the nondestructive inspection of mechanical systems used in service. For reliable fault monitoring related to the crack growth, it is important to identify the dynamical characteristics as well as transient crack-related signals. Widely used methods which are based on physical phenomena of the three damage stages for detecting the crack growth have a problem that crack-related acoustic emission activities overlap in time, therefore it is insufficient to estimate the exact crack growth time. The proposed pattern recognition method uses the dynamical characteristics of acoustic emission as inputs for minimizing false alarms and miss alarms and performs the temporal clustering to estimate the crack growth time accurately. Experimental results show that the proposed method is effective for practical use because of its robustness to changes of acoustic emission caused by changes of pressure levels.

Development of T2DM Prediction Model Using RNN (RNN을 이용한 제2형 당뇨병 예측모델 개발)

  • Jang, Jin-Su;Lee, Min-Jun;Lee, Tae-Ro
    • Journal of Digital Convergence
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    • v.17 no.8
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    • pp.249-255
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    • 2019
  • Type 2 diabetes mellitus(T2DM) is included in metabolic disorders characterized by hyperglycemia, which causes many complications, and requires long-term treatment resulting in massive medical expenses each year. There have been many studies to solve this problem, but the existing studies have not been accurate by learning and predicting the data at specific time point. Thus, this study proposed a model using RNN to increase the accuracy of prediction of T2DM. This work propose a T2DM prediction model based on Korean Genome and Epidemiology study(Ansan, Anseong Korea). We trained all of the data over time to create prediction model of diabetes. To verify the results of the prediction model, we compared the accuracy with the existing machine learning methods, LR, k-NN, and SVM. Proposed prediction model accuracy was 0.92 and the AUC was 0.92, which were higher than the other. Therefore predicting the onset of T2DM by using the proposed diabetes prediction model in this study, it could lead to healthier lifestyle and hyperglycemic control resulting in lower risk of diabetes by alerted diabetes occurrence.

Mortality rate undergoing anesthesia in Thoroughbred racehorses at Busan Race Park (부산경남경마공원 Thoroughbred 경주마의 마취중 치사율)

  • Yang, Jaehyuk;Park, Yong-Soo
    • Journal of Practical Agriculture & Fisheries Research
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    • v.17 no.1
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    • pp.125-132
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    • 2015
  • The report about equine anesthesias in Korea are very rare. This paper aimed at the mortality rate during anesthesia in Thoroughbred horses at Equine Hospital of Busan Race Park, KRA in South Korea from 2005 to 2010. Drugs used in anesthesia was IV injection of detomidine hydrochloride (0.01 mg/kg) or xylazine(0.5mg/kg) for sedation and premedication, Guaifenesin(50-100 mg/kg) for muscle relaxation, ketamine hydrochloride(2 mg/kg) for induction of anaesthesia and Inhalational isoflurane(1.3-1.5 %) to maintain anesthesia. Total number of anesthetic cases was 190, 150 of inhalational anesthesia and 40 of general anesthesia, repectively. The purpose of anesthesia was highest in the disorder of musculoskeletal system, followed by urogenital system and respiratory system Mortality case due to anesthesia was one during arthroscopic surgery for removal of osteochondral chip fragments. The time of anesthesia was 150 min, fatal sign was hypoxemia and the reason was improper machine operation of the anesthetist. In conclusion, the perianesthetic mortality rate during anesthesia in Thoroughbred horses at Busan Race Park was 0.52%(1 death per 190 anesthetics).

Clinical Characteristics and Prognosis of Elderly Patients Receiving Prolonged Mechanical Ventilation in the Medical Intensive Care Unit at a University Hospital (한 대학병원 내과계 중환자실에서 장기간 기계환기를 받은 노인 환자들의 특징 및 예후)

  • Han, Min Soo;Moon, Kyoung Min;Lee, Yang Deok;Cho, Yongseon;Na, Dong Jib
    • Tuberculosis and Respiratory Diseases
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    • v.64 no.6
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    • pp.445-450
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    • 2008
  • Background: As the number of older-aged people increases, the number of elderly patients who receive critical care services is expected to increase substantially. The objective of this study was to examine the clinical characteristics and outcomes of elderly patients who receive mechanical ventilation for more than 30 days in the medical intensive care unit (MICU) at a university hospital. Methods: We retrospectively examined forty-one elderly patients (${\geq}65$ years old) who were receiving mechanical ventilation, from April 2004 to March 2007, for periods exceeding 30 days at the MICU at Eulji University Hospital. Results: The MICU and hospitalmortality rate were 60.9% and 65.9%, respectively. The mean length of the ICU stay was 57.5 days and the mean duration of mechanical ventilation was 49.3 days. The most common reason for MICU admission was acute respiratory failure (73.2%), followed by sepsis (12.2%), neurological problems (9.8%), and gastrointestinal bleeding (4.9%). The Acute Physiology and Chronic Health Evaluation (APACHE) II scores were higher for the nonsurvivors than for the survivors (28.0 vs. 25.0, respectively, p=0.03). The nonsurvivors received more red blood cell (RBC) transfusions during their ICU stay than did the survivors (84.0% vs. 43.8%, respectively p=0.007). The factors associated with hospital death were the APACHE II score and if the patient had received a RBC transfusion. Conclusion: The APACHE II score and a RBC transfusion were predictors of increased hospital mortality for the elderly patients who were on prolonged mechanical ventilation. These predictors may assist physicians to make clinical decisions for this patient population.

The Changes of Cuff Pressure from Endotracheal Intubation for Long-term Mechanical Ventilation (장기간 기계호흡 환자에서 기관내 관의 기낭압의 변화)

  • Jung, Bock-Hyun;Park, Whan;Koh, Youn-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.52 no.2
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    • pp.156-165
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    • 2002
  • Background: A tracheal stenosis is caused by mucosal ischemic injury related to a high cuff pressure ($P_{cuff}$) of the endotracheal tube. In contrast, aspiration of the upper airway secretion and impaired gas exchange due to cuff leakage is related to a low $P_{cuff}$. To prevent these complications, the $P_{cuff}$ should be kept appropriately because the appropriate $P_{cuff}$ appears to change according to the patient's daily respiratory mechanics. However, the constant cuff volume($V_{cuff}$) has frequently been instilled to the cuff balloon on a daily basis to maintain the optimal $P_{cuff}$ instead of monitoring the $P_{cuff}$ directly at the patients' bedside. To address the necessity of continuous $P_{cuff}$ monitoring, the change in the $P_{cuff}$ was evaluated at various $V_{cuff}$ levels on a daily basis in patients with long-term mechanical ventilation. The utility of mercury column sphygmomanometer for the continuous monitoring $P_{cuff}$ was also investigated. Method: The change in $P_{cuff}$ according to the increase in $V_{cuff}$ was observed in 17 patients with prolonged endotracheal intubation for mechanical ventilation for 2 week or more. This maneuver measured the change in $P_{cuff}$ daily during the mechanical ventilation days. In addition, the $P_{cuff}$ measured by mercury column sphygmomanometer was compared with the $P_{cuff}$ measured by an automatic cuff pressure manager. Results : There were no statistically significant changes of $P_{cuff}$ during more than 14 days of intubation for mechanical ventilation. However the $V_{cuff}$ required to maintain the appropriate $P_{cuff}$ varied from 1.9 cc to 9.6 cc. In addition, the intra-individual variation of the $P_{cuff}$ was observed from 10 $cmH_2O$ to 46 $cmH_2O$ at constant 3 cc $V_{cuff}$. The $P_{cuff}$ measured by the bedside mercury column sphygmomanometer is well coincident with that measured by the automatic cuff pressure manager. Conclusion: Continuous monitoring and management of the $P_{cuff}$ to maintain the appropriate $P_{cuff}$ level in order to prevent cuff related problems during long-term mechanical ventilation is recommended. For this purpose, mercury column sphygmomanometer may replace the specific cuff pressure monitoring equipment.

The Findings of Pulmonary Function Test in Patients with Inhalation Injury (흡입화상 환자에서의 폐기능검사 소견)

  • Kim, Jong Yeop;Kim, Cheol Hong;Shin, Hyun Won;Chae, Young Je;Choi, Chul Young;Shin, Tae Rim;Park, Yong Bum;Lee, Jae Young;Bahn, Joon-Woo;Park, Sang Myeon;Kim, Dong-Gyu;Lee, Myung Goo;Hyun, In-Gyu;Jung, Ki-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.60 no.6
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    • pp.653-662
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    • 2006
  • Background: The changes in the pulmonary function observed in burn patients with an inhalation injury are probably the result of a combination of airway inflammation, chest wall and muscular abnormalities, and scar formation. In addition, it appears that prolonged ventilatory support and an episode of pneumonia contribute to the findings. This study investigated the changes in the pulmonary function in patients with inhalation injury at the early and late post-burn periods. Methods: From August 1, 2002, to August 30, 2005, surviving burn patients who had an inhalation injury were enrolled prospectively. An inhalation injury was identified by bronchoscopy within 48hours after admission. Spirometry was performed at the early phase during admission and the recovery phase after discharge, and the changes in the pulmonary function were compared. Results: 37 patients (M=28, F=9) with a total burn surface area (% TBSA), ranging from 0 to 18%, were included. The initial $PaO_2/$FiO_2$ratio and COHb were $286.4{\pm}129.6mmHg$ and $7.8{\pm}6.6%$. Nine cases (24.3%) underwent endotracheal intubation and 3 cases (8.1%) underwent mechanical ventilation. The initial X-ray findings revealed abnormalities in, 18 cases (48.6%) with 15 (83.3%) of these being completely resolved. However, 3 (16.7%) of these had residual sequela. The initial pulmonary function test, showed an obstructive pattern in 9 (24.3%) with 4 (44.4%) of these showing a positive bronchodilator response, A restrictive pattern was also observed in 9 (24.3%) patients. A lower DLco was observed in only 4 (17.4%) patients of which 23 had undergone DLco. In the follow-up study, an obstructive and restrictive pattern was observed in only one (2.7%) case each. All the decreased DLco returned to mormal. Conclusions: Most surviving burn patients with an inhalation injury but with a small burn size showed initial derangements in the pulmonary function test that was restored to a normal lung function during the follow up period.

Artificial Intelligence In Wheelchair: From Technology for Autonomy to Technology for Interdependence and Care (휠체어 탄 인공지능: 자율적 기술에서 상호의존과 돌봄의 기술로)

  • HA, Dae-Cheong
    • Journal of Science and Technology Studies
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    • v.19 no.2
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    • pp.169-206
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    • 2019
  • This article seeks to explore new relationships and ethics of human and technology by analyzing a cultural imaginary produced by artificial intelligence. Drawing on theoretical reflections of the Feminist Scientific and Technological Studies which understand science and technology as the matter of care(Puig de la Bellacas, 2011), this paper focuses on the fact that artificial intelligence and robots materialize cultural imaginary such as autonomy. This autonomy, defined as the capacity to adapt to a new environment through self-learning, is accepted as a way to conceptualize an authentic human or an ideal subject. However, this article argues that artificial intelligence is mediated by and dependent on invisible human labor and complex material devices, suggesting that such autonomy is close to fiction. The recent growth of the so-called 'assistant technology' shows that it is differentially visualizing the care work of both machines and humans. Technology and its cultural imaginary hide the care work of human workers and actively visualize the one of the machine. And they make autonomy and agency ideal humanness, leaving disabled bodies and dependency as unworthy. Artificial intelligence and its cultural imaginary negate the value of disabled bodies while idealizing abled-bodies, and result in eliminating the real relationship between man and technology as mutually dependent beings. In conclusion, the author argues that the technology we need is not the one to exclude the non-typical bodies and care work of others, but the one to include them as they are. This technology responsibly empathizes marginalized beings and encourages solidarity between fragile beings. Inspired by an art performance of artist Sue Austin, the author finally comes up with and suggests 'artificial intelligence in wheelchair' as an alternative figuration for the currently dominant 'autonomous artificial intelligence'.