• 제목/요약/키워드: critical current ratio

검색결과 174건 처리시간 0.027초

부동 소수점 DSP를 이용한 MPEG-4 HVXC 인코더 및 디코더의 실시간 구현 (Real-time Implementation of MPEG-4 HVXC Encoder and Decoder on Floating Point DSP)

  • 강경옥;나훈;홍진우;정대권
    • 한국음향학회지
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    • 제19권4호
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    • pp.37-44
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    • 2000
  • 본 논문에서는 인터넷 폰, 디지털 이동통신 등과 같이 낮은 비트율이 요구되는 분야에 사용될 수 있는 MPEG-4 오디오의 HVXC(Harmonic Vector eXcitation Coding) 알고리즘을 부동 소수점 DSP인 TMS320C6701에 실시간 구현한 내용을 기술한다. 실시간 동작을 위한 하드웨어 구조를 채택하였으며, 소프트웨어 최적화의 경우 연산 시간이 많이 소요되는 함수 루틴에 대한 C 언어 및 어셈블리 언어 레벨의 최적화를 수행하였다. 또한, DSP의 내부 프로그램 메모리의 프로그램 캐쉬로의 활용, DSP의 내부 데이터 메모리의 영역의 중첩 활용 및 background DMA 방식을 이용한 최적화를 수행하였다. 최적화 결과 2kbps및 4kbps의 비트율에서 압축 및 복원을 실시간으로 수행할 수 있으며, 인코더의 경우 2kbps의 경우에는 최적화 전에 비해 약 96% 정도로 수행시간을 단축하였다. 또한, 비공식 주관품질 평가에 의하면 2kbps의 비트율에서 약 MOS 2.45를 얻었다.

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질산염 무기금속 화합물의 분무열분해법에 의한 High-$J_c$ YBCO 박막 제조 (Preparation of High $J_c$ YBCO Films on LAO by Spray Pyrolysis Process Using Nitrate Precursors)

  • 홍석관;김재근;김호진;조한우;유석구;안지현;주진호;이희균;홍계원
    • Progress in Superconductivity
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    • 제8권1호
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    • pp.71-74
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    • 2006
  • High $J_c$ over 1 $MA/cm^2$ YBCO film has been successfully prepared using nitrate precursors by spray pyrolysis method. Aerosol drolpets generated using a concentric spray nozzle were directly sprayed on a $LaAlO_3$(100) single crystal substrate. The cation ratio of precursor solution was Y:Ba:Cu=1:2.65:1.35. The distance between nozzle and substrate was 15 cm. Deposition temperature was ranging from $750^{\circ}C\;to\;800^{\circ}C$. Deposition pressure was 100 Torr, and oxygen partial pressure was varied from 10 Torr to 50 Torr. The microstructure, phase formation, texture development and superconducting properties of deposited films were largely changed with oxygen partial pressure. Deposited films showed a texture with(001) planes parallel to substrate plane. High quality film was obtained when film was deposited at $760^{\circ}C$ with an oxygen partial pressure of 30 Torr. The critical current density($J_c$) of the YBCO film was 1.75 $MA/cm^2$ at 77 K and self-field.

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소아 안면골 골절의 임상 분석; 10년 동안 201례의 경험 (Clinical Analysis of Pediatric Facial Bone Fracture; 10-years Experiences in 201 Cases)

  • 오민;김영수;윤효헌;최준
    • Archives of Plastic Surgery
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    • 제32권1호
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    • pp.55-59
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    • 2005
  • The proper management of the pediatric facial bone fracture is critical in the facial bone development. This study characterizes the surgically treated patient population suffering from facial bone fractures by the use of current data from a large series consisting of 201 cases. The data was gathered through a retrospective chart review of patients surgically treated for facial bone fractures at the department of plastic and reconstructive surgery, Sanggye Paik hospital, Inje university medical center, collected over 10-years period from January, 1993 to December, 2002. Data regarding patient demographics(age, sex), seasonal distribution, location of fractures, and the causes of injury with admission periods, were collected. In total, there were 201cases of pediatric facial bone fractures. Male patients outnumbered female patients by a 5.48: 1 ratio and were found to engage in a wider range of behaviors that resulted in facial bone fractures. Physical violence was the leading cause of pediatric facial bone fractures(27.9%), followed by sports-related mechanisms (22.9%) and falling down(17.9%). The most prevalent age group was 11-15 years-old(71.1%) and there was a 14.3% prevalence in March. Among the location of fractures, the nasal bone was the most prevalent, accounting for 82.3% of injuries, followed by the orbit(9.95%), and the mandible fractures(7.5%). Most patients(59.7%) were treated within 6-9 days after trauma and the mean hospitalization period was 8-11 days. We should follow up the surgically treated patients, and they will be further evaluated about postoperative sequele and effect on the facial bone development. These studies demonstrate differences in the demographics and clinical presentation that, if applied to patients, will enable a more accurate diagnosis and proper management.

Indicators and Qualitative Assessment of Lung Cancer Management by Health Insurance Review and Assessment Service (HIRA) of Korea in 2015

  • Yeo, Chang Dong;Lee, Myoung Kyu;Lee, Seung Hyeun;Kim, Eun Young;Lee, Ik Jae;Park, Heae Surng;Chang, Yoon Soo
    • Tuberculosis and Respiratory Diseases
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    • 제81권1호
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    • pp.19-28
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    • 2018
  • Cancer is the leading cause of death in the Republic of Korea and cancer death accounts for 27.8% of the total deaths, which is not only a social issue but also a concern for the public. Among the cancer death rates, lung cancer mortality account for 34 deaths per 100,000 populations, making it the number one cancer death rate. In a preliminary report on cancer death in 2012, the lung cancer mortality ratio showed the regional variation indicating that there were differences in the qualitative level and the structure among the medical care benefit agency and in the assessment of the treatment process. Therefore, the Health Insurance Review and Assessment Service (HIRA) had begun evaluation of the assessment of lung cancer treatment since 2014 to improve the quality of lung cancer care through evaluation and feeds back the results of lung cancer care process. In this report, authors described the current Indicators for the lung cancer adequacy assessment proposed by HIRA and results of the evaluation reported in 2017.

몬테카를로 광선추적법을 이용한 태양로의 열유속 해석 (Heat-Flux Analysis of Solar Furnace Using the Monte Carlo Ray-Tracing Method)

  • 이현진;김종규;이상남;강용혁
    • 대한기계학회논문집B
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    • 제35권10호
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    • pp.989-996
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    • 2011
  • 태양의 집광 열유속을 이해하는 것은 태양에너지를 이용하는 시스템의 해석과 설계에 중요하다. 본 연구는 우수한 유연성과 확장성을 가진 몬테카를로 광선추적법에 기반하면서 태양주연감광과 반사판 표면 기울기 에러를 고려하는 알고리듬 개발과 이를 통한 태양 열유속 해석에 초점을 맞추고 있다. 검증을 위해 한국에너지기술연구원 태양로에서 측정된 열유속과 비교했을 때, 모델링 결과가 측정 에러 범위인 10% 이내에서 잘 일치하였다. 개발된 모델을 통해 태양로의 집광 성능을 2 mrad 의 추적 정밀도에 최대로 도달 가능한 집광비가 4400 sun 으로 평가하였다. 열유속의 측정 위치에 따른 변화와 수광각에 따른 분포를 통해 화학반응기나 보조집광기 설계에 필요한 상세한 정보를 제공하였다.

Analysis of composite girders with hybrid GFRP hat-shape sections and concrete slab

  • Alizadeh, Elham;Dehestani, Mehdi
    • Structural Engineering and Mechanics
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    • 제54권6호
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    • pp.1135-1152
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    • 2015
  • Most of current bridge decks are made of reinforced concrete and often deteriorate at a relatively rapid rate in operational environments. The quick deterioration of the deck often impacts other critical components of the bridge. Another disadvantage of the concrete deck is its high weight in long-span bridges. Therefore, it is essential to examine new materials and innovative designs using hybrid system consisting conventional materials such as concrete and steel with FRP plates which is also known as composite deck. Since these decks are relatively new, so it would be useful to evaluate their performances in more details. The present study is dedicated to Hat-Shape composite girder with concrete slab. The structural performance of girder was evaluated with nonlinear finite element method by using ABAQUS and numerical results have been compared with experimental results of other researches. After ensuring the validity of numerical modeling of composite deck, parametric studies have been conducted; such as investigating the effects of constituent properties by changing the compressive strength of concrete slab and Elasticity modulus of GFRP materials. The efficacy of the GFRP box girders has been studied by changing GFRP material to steel and aluminum. In addition, the effect of Cross-Sectional Configuration has been evaluated. It was found that the behavior of this type of composite girders can be studied with numerical methods without carrying out costly experiments. The material properties can be modified to improve ultimate load capacity of the composite girder. strength-to-weight ratio of the girder increased by changing the GFRP material to aluminum and ultimate load capacity enhanced by deformation of composite girder cross-section.

Automatic False-Alarm Labeling for Sensor Data

  • Adi, Taufik Nur;Bae, Hyerim;Wahid, Nur Ahmad
    • 한국컴퓨터정보학회논문지
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    • 제24권2호
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    • pp.139-147
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    • 2019
  • A false alarm, which is an incorrect report of an emergency, could trigger an unnecessary action. The predictive maintenance framework developed in our previous work has a feature whereby a machine alarm is triggered based on sensor data evaluation. The sensor data evaluator performs three essential evaluation steps. First, it evaluates each sensor data value based on its threshold (lower and upper bound) and labels the data value as "alarm" when the threshold is exceeded. Second, it calculates the duration of the occurrence of the alarm. Finally, in the third step, a domain expert is required to assess the results from the previous two steps and to determine, thereby, whether the alarm is true or false. There are drawbacks of the current evaluation method. It suffers from a high false-alarm ratio, and moreover, given the vast amount of sensor data to be assessed by the domain expert, the process of evaluation is prolonged and inefficient. In this paper, we propose a method for automatic false-alarm labeling that mimics how the domain expert determines false alarms. The domain expert determines false alarms by evaluating two critical factors, specifically the duration of alarm occurrence and identification of anomalies before or while the alarm occurs. In our proposed method, Hierarchical Temporal Memory (HTM) is utilized to detect anomalies. It is an unsupervised approach that is suitable to our main data characteristic, which is the lack of an example of the normal form of sensor data. The result shows that the technique is effective for automatic labeling of false alarms in sensor data.

Development of a Korean Diet Score (KDS) and its application assessing adherence to Korean healthy diet based on the Korean Food Guide Wheels

  • Lee, Myoungsook;Chae, Soo Wan;Cha, Youn-Soo;Cho, Mi Sook;Oh, Hea Young;Kim, Mi Kyung
    • Nutrition Research and Practice
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    • 제7권1호
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    • pp.49-58
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    • 2013
  • The most critical point in the assessment of adherence to dietary guidelines is the development of a practical definition for adherence, such as a dietary pattern score. The purpose of this study was to develop the Korean Diet Score (KDS) based on the Korean Food Balance Wheel and to examine the association of KDS with various lifestyle characteristics and biochemical factors. The dietary data of 5,320 subjects from the 4th Korean National Health and Nutritional Examination Survey were used for the final analysis. The food guide was composed of six food group categories; 'grain dishes', 'fish and meat dishes', 'vegetable dishes', 'fruits', 'milk' and 'oils and sugars'. Based on the recommended serving numbers for each group, the scores measuring adherence to this food guide were calculated from the dietary information from the 24-hour dietary recall questionnaire, and then its correlation with various characteristics was assessed. KDS was significantly associated with several clinical, lifestyle and socioeconomic factors as well as diagnosed disease history. The higher quintile group of KDS showed a significantly lower level in fasting blood glucose, systolic blood pressure, triglycerides, current smoking and drinking as well as higher leisure time activity, house income and education. Furthermore, the KDS quintile group of women was inversely associated with hypertension, osteoporosis and diabetes. A higher KDS quintile was characterized with a higher intake of several critical nutrients, such as Ca, Fe and vitamins as well as a desirable nutrition balance such as the ratio of macronutrients. Our results demonstrate that KDS is a beneficial tool in assessing the adherence to a healthy diet based on the Korean dietary guidelines. We suggest that KDS could be a useful indicator for evaluating the dietary balance of the Korean population.

Genetic diversity evolution in the Mexican Charolais cattle population

  • Rios-Utrera, Angel;Montano-Bermudez, Moises;Vega-Murillo, Vicente Eliezer;Martinez-Velazquez, Guillermo;Baeza-Rodriguez, Juan Jose;Roman-Ponce, Sergio Ivan
    • Animal Bioscience
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    • 제34권7호
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    • pp.1116-1122
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    • 2021
  • Objective: The aim was to characterize the genetic diversity evolution of the registered Mexican Charolais cattle population by pedigree analysis. Methods: Data consisted of 331,390 pedigree records of animals born from 1934 to 2018. Average complete generation equivalent, generation interval, effective population size (Ne), and effective numbers of founders (fe), ancestors (fa), and founder genomes (Ng) were calculated for seven five-year periods. The inbreeding coefficient was calculated per year of birth, from 1984 to 2018, whereas the gene contribution of the most influential ancestors was calculated for the latter period. Results: Average complete generation equivalent consistently increased across periods, from 4.76, for the first period (1984 through 1988), to 7.86, for the last period (2014 through 2018). The inbreeding coefficient showed a relative steadiness across the last seventeen years, oscillating from 0.0110 to 0.0145. During the last period, the average generation interval for the father-offspring pathways was nearly 1 yr. longer than that of the mother-offspring pathways. The effective population size increased steadily since 1984 (105.0) and until 2013 (237.1), but showed a minor decline from 2013 to 2018 (233.2). The population displayed an increase in the fa since 1984 and until 2008; however, showed a small decrease during the last decade. The effective number of founder genomes increased from 1984 to 2003, but revealed loss of genetic variability during the last fifteen years (from 136.4 to 127.7). The fa:fe ratio suggests that the genetic diversity loss was partially caused by formation of genetic bottlenecks in the pedigree; in addition, the Ng:fa ratio indicates loss of founder alleles due to genetic drift. The most influential ancestor explained 1.8% of the total genetic variability in the progeny born from 2014 to 2018. Conclusion: Inbreeding, Ne, fa, and Ng are rather beyond critical levels; therefore, the current genetic status of the population is not at risk.

일개 권역응급의료센터에서의 중증 외상환자의 전원 현황과 문제점 (Current State and Problem of the Transfer of Severely Injured Patients in One Regional Emergency Medical Center)

  • 이원철;조충현;정경원;민영기;최상천;김기운;안정환;정용식;황선애;김지영;이국종;정윤석
    • Journal of Trauma and Injury
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    • 제23권1호
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    • pp.6-15
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    • 2010
  • Purpose: Trauma is one of the leading causes of death, especially among young people. Life-threatening conditions are very common in multiple-traumatized patients due to concurrent multi-organ injuries. Treating such severely injured patients is time critical. However, in Korea, the transfer of severely injured patients is not uncommon due to the lack of a mature trauma care system. In developed countries, the preventable trauma death rate is very low, but the rate is still very high in Korea. This study's objective was to demonstrate the current serious state in which severely injured patients have to be transferred from a Regional Emergency Medical Center even though it actually serves as a trauma center. Methods: Ajou University Medical Center is a tertiary hospital that serves as a trauma center in Gyeonggido. The medical records at Ajou University Medical Center for a 1-year period from January 1, 2008, to December 31, 2008, were retrospectively reviewed. A severely injured patient was defined as a patient who showed more than 15 point on the ISS (injury severity score) scale. We investigated the clinical characteristics of such patients and the causes of transfer. Results: Out of 81,718 patients who visited the Regional Emergency Medical Center, 19,731 (24.1%) were injured patients. Among them, 108 severely-injured patients were transferred from one Regional Emergency Medical Center to other hospitals. The male-to-female ratio was about 3.5:1, and the mean ISS was 23.08. The most common mechanism of injury was traffic accidents (41.7%). A major cause of transfer was the shortage of intensive care units (44.4%); another was for emergent operation (27.8%). Most of the hospitals that received the severely-injured patients were secondary hospitals (86.1%). Conclusion: Although the Regional Emergency Medical Center played a role as a trauma center, actually, severely-injured patients had to be transferred to other hospitals for several reasons. Most reasons were related with the deficiencies in the trauma care system. If a mature trauma care system is well-organized, the numbers of transfer of severely injured patients will be reduced significantly.