• 제목/요약/키워드: rotation period

검색결과 340건 처리시간 0.027초

Generalized One-Level Rotation Designs with Finite Rotation Groups Part I:Generatio of Designs

  • Park, You-Sung;Kim, Kee-Whan
    • Journal of the Korean Statistical Society
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    • 제29권1호
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    • pp.29-44
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    • 2000
  • In this paper, we consider one-level rotation designs with finite rotation groups such that the design satisfies two basic requirements: all rotation groups are included in any given survey period, and overlapping rates depend only on the time lag. First we present the necessary number of rotation groups and a rule for the length of time the sample units are to be in or out of the sample to satisfy the requirements. Second, an algorithm is presented to put rotation groups to proper positions in a panel in order to include all finite rotation groups for any survey period. Third, we define an one-level rotation pattern which is invariant in the survey period and has useful properties in practical sense.

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Effect of the Growth Period on Bioethanol Production from the Branches of Woody Crops Cultivated in Short-rotation Coppices

  • Jo, Jong-Soo;Jung, Ji Young;Yang, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • 제47권3호
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    • pp.360-370
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    • 2019
  • Woody crops cultivated in short-rotation coppices are attractive sources of lignocellulosic materials for bioethanol production, since they are some of the most abundant renewable resources. In this study, we evaluated the effects of the growth period on bioethanol production using short-rotation woody crops (Populus nigra ${\times}$ Populus maxiwiczii, Populus euramericana, Populus alba ${\times}$ Populus glandulosa, and Salix alba). The carbohydrate contents of 3-year-old and 12-year-old short-rotation woody crop branches were 62.1-68.5% and 64.0-67.1%, respectively. The chemical compositions of 3-year-old and 12-year-old short-rotation woody crop branches did not vary significantly depending upon the growth period. However, the 3-year-old short-rotation woody crop branches (glucose conversion: 26-40%) were hydrolyzed more easily than their 12-year-old counterparts (glucose conversion: 19-24%). Furthermore, following the fermentation of enzymatic hydrolysates from the crop branch samples (by Saccharomyces cerevisiae KCTC 7296) to ethanol, the ethanol concentration of short rotation coppice woody crops was found to be higher in the 3-year-old branch samples (~ 0.18 g/g dry matter) than in the 12-year-old branch samples (~ 0.14 g/g dry matter). These results suggest that immature wood (3-year-old branches) from short-rotation woody crops could be a promising feedstock for bioethanol production.

The Impact of Abdominal Drawing-in Maneuver and Tensor Fasciae Latae-iliotibial Band Self-stretching on Lumbopelvic Kinematics in Individuals With Lumbar Extension Rotation Syndrome

  • One-bin Lim;Oh-yun Kwon;Heon-seock Cynn;Chung-hwi Yi
    • 한국전문물리치료학회지
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    • 제31권1호
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    • pp.79-88
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    • 2024
  • Background: The abdominal drawing-in maneuver (ADIM), a method of lumbar stabilization training, is an effective neuromuscular intervention for lumbar instability associated with low back pain (LBP). Objects: The purpose of this study was to compare the effect of a 2-week period of the ADIM and tensor fasciae latae-iliotibial band (TFL-ITB) self-stretching on lumbopelvic rotation angle, lumbopelvic rotation movement onset, TFL-ITB length, and pain intensity during active prone hip lateral rotation. Methods: Twenty-two subjects with lumbar extension rotation syndrome accompanying shortened TFL-ITB (16 males and 6 females) were recruited for this study. The subjects were instructed how to perform ADIM training or ADIM training plus TFL-ITB self-stretching program at home for a 2-week period. A 3-dimensional ultrasonic motion analysis system was used to measure the lumbopelvic rotation angle and lumbopelvic rotation movement onset. An independent t-test was used to determine between-group differences for each outcome measure (lumbopelvic rotation angle, lumbopelvic rotation movement onset, TFL-ITB length, and pain intensity). Results: The results showed that ADIM training plus TFL-ITB self-stretching decreased the lumbopelvic rotation angle, delayed the lumbopelvic rotation movement onset, and elongated the TFL-ITB significantly more than did ADIM training alone. Pain intensity was lower in the ADIM training plus TFL-ITB self-stretching group than the ADIM training alone group; however, the difference was not significant. Conclusion: ADIM training plus TFL-ITB self-stretching performed for a 2-week period at home may be an effective treatment for modifying lumbopelvic motion and reducing LBP.

목표림(目標林)모델에 의한 최적윤벌기(最適輪伐期) 결정(決定)에 관한 연구(硏究) - 잣나무 임분(林分)을 중심으로 - (A Study on the Determination of the Optimal Rotation Period by Target Forest Model - Centered with Korean White Pine Stands -)

  • 우종춘
    • 한국산림과학회지
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    • 제83권2호
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    • pp.121-132
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    • 1994
  • 윤벌기(輪伐期)는 각 영급이 존재하는 삼림의 생산(生産)을 조절하기 위해서 설정된 삼림경영목표(森林經營目標)중 가장 중요한 인자중의 하나이다. 본 연구(硏究)에서는 특히 최적화(最適化)계산의 형태로 법정임(法正林)모델에서의 최적윤벌기(最適輪伐期)가 추정(推定)되었다. 그리고 법정림모델과의 연계하에 자연상태에서 여러가지 위험조건에 처해있는 현실임분(現實林分)에 더욱 접근시키기 위하여 목표임(目標林)모델이 간단작업급삼림(間斷作業級森林)모델(모델 1)과 연년보속작업급삼림(連年保續作業級森林)모델(모델 2)의 두가지로 나뉘어 전개되었으며 이 두 모델에 의해 최적윤벌기가 계산되었다. 동시에 법정림모델, 목표림모델 1, 2에 의해 추정된 최적윤벌기가 상호 비교되었다. 이때 강원대학교(江原大學校) 임과대학(林科大學) 부속(附屬) 연습림(演習林) 내(內) 잣나무임분이 최적윤벌기(最適輪伐期) 계산의 대상이 되었다.

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뇌졸중(腦卒中) 전조증상(前兆症狀)으로서의 현훈(眩暈)에 대한 설문조사분석(設問調査分析) (A Questionaire Analysis for the Vertigo as the prodrome of Stroke)

  • 고성규;용형순
    • 대한한방내과학회지
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    • 제21권1호
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    • pp.135-145
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    • 2000
  • Objective : This study has been made to analysis of clinical type of vertigo prodromic Cerebral Vascular Disease in stroke patients who admitted to sangji oriental hospital department of circulatoty internal medicine in the period from July. 1999 to October 1999. Methods : A Questionaire was done after explanationin details to patients and agreement of patients. The inquire was done as follows. Sex and age, risk factor of stroke, type of stroke, existence of vertigo last three years before stroke attack, the beginning age of vertigo and period of prevalence, frequency, continuance time of vertigo, predilection season and time, factor of causing vertigo, accompanying symptoms of vertigo, severity of vertigo. Result and Conclusion : The existence of Rotation sense(Rotation group and non-Rotation group) and the type of Stroke is no difference significantly but the Rotation vertigo group and non-Rotation vertigo group is difference significantly in distribution. The sixties in age of vertigo attack, previous vertigo before 3 year Stroke attack, irregular in predilection season of vertigo, have a high frequency significantly in distribution and previous period of vertigo has no significantly difference in distribution. One or two per a month in frequency of vertigo, below 5 minute in continuance time of vertigo, irregular in predilection time of vertigo, stand up and sit down in causing vertigo position have a high frequency significantly in distribution.

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Effects of the Instrument Pilates Exercise Based on the Schroth Exercise on the Cobb's Angle, Angle of Trunk Rotation and Low Back Pain in Patients with Idiopathic Scoliosis: A Single Subject Study

  • Song, Ki Yeon;Baek, Ki Hyun;Lim, Mi Soo;Lim, Hyoung-won
    • The Journal of Korean Physical Therapy
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    • 제33권2호
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    • pp.97-105
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    • 2021
  • Purpose: This study examined the effects of the application of Schroth exercise-based instrument Pilates exercise on the Cobb's angle, angle of trunk rotation, and low back pain of female patients with idiopathic scoliosis. Methods: Three patients with idiopathic scoliosis at a Cobb's angle of 20° or more participated in this study. Among the single-subject experimental research designs, a reversal (ABA) design was performed. In particular, Schroth exercise-based instrument, Pilates exercise, was performed for 10 weeks, consisting of five weeks between the baseline and intervention one period and five weeks between the intervention 1 and intervention 2 periods, and then followed up for five weeks. Results: After the Schroth exercise-based instrument, Pilates exercise, was applied, the Cobb's angle and the angle of trunk rotation decreased compared to the baseline in all subjects, and the follow-up period also showed a continuous decline. After Pilates exercise was performed, low back pain in subjects 1 and 2 was decreased in the intervention 1 period compared to the baseline. The level of low back pain in the intervention 2 period increased compared to the intervention 1 period, but a reduction was noted in the follow-up period. The low back pain in the subject was decreased in all intervention periods and the follow-up period. Conclusion: Schroth exercise-based Pilates exercise improves the Cobb's angle and the angle of trunk rotation for female patients with idiopathic scoliosis in their teens and 20s, and an effective intervention method is proposed for low back pain.

Effects of Tensor Fasciae Latae-Iliotibial Band Self-Stretching on Lumbopelvic Movement Patterns During Active Prone Hip Lateral Rotation in Subjects With Lumbar Extension Rotation Syndrome

  • Lim, One-Bin;Yi, Chung-Hwi;Kwon, Oh-Yun;Cynn, Heon-Seock
    • 한국전문물리치료학회지
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    • 제19권4호
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    • pp.61-69
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    • 2012
  • The purpose of this study was to identify the effects of tensor fasciae latae-iliotibial band (TFL-ITB) self-stretching exercise on the lumbopelvic movement patterns during active prone hip lateral rotation (HLR) in subjects with lumbar extension rotation syndrome accompanying TFL-ITB shortness. Eleven subjects (9 male and 2 female) were recruited for the two-week study. A three dimensional ultrasonic motion analysis system was used to measure the lumbopelvic movement patterns. The TFL-ITB length was measured using the modified Ober's test and was expressed as the hip horizontal adduction angle. The subjects were instructed how to perform TFL-ITB self-stretching exercise program at home. A paired t-test was performed to determine the significant difference in the angle of lumbopelvic rotation, movement onset time of lumbopelvic rotation, TFL-ITB length, and LBP intensity before and after the two-week period of performing the TFL-ITB self-stretching exercise. The results showed that after the intervention, the lumbopelvic rotation angle decreased significantly (p<.05), the movement onset time reduced significantly (p<.05), and LBP intensity decreased slightly but not significantly (p=.07). The hip horizontal adduction angle increased significantly (p<.05) after the intervention. These findings indicate that TFL-ITB stretching exercise increased TFL-ITB length, decreased lumbopelvic rotation angle, and delayed the movement onset time of lumbopelvic rotation after two-weeks. In conclusion, the TFL-ITB self-stretching exercise performed over a period of two weeks may be an effective approach for patients with lumbar extension rotation syndrome accompanying TFL-ITB shortness.

공무원 순환보직에 관한 연구 (A Study on Job Rotation in Civil Service)

  • 김광호
    • KDI Journal of Economic Policy
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    • 제30권2호
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    • pp.61-97
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    • 2008
  • 본 연구는 공무원의 전문성 축적을 저해하는 것으로 지속적으로 지적되는 순환보직의 실태를 파악하고 그 개선방안을 제시하는 것을 목적으로 한다. 우리나라 중앙부처 과장급 이상 공무원의 평균재직기간은 1년 남짓으로 매우 짧아 업무의 인수 인계에서 오는 비효율 및 업무공백, 전문성 축적기회의 감소, 책임성 저하, 정책의 일관성 및 연속성 결여 등 여러 문제를 낳으며, 특히 고도의 전문성을 요하는 대외 협상 분야에서 큰 국가적 손실을 낳는 것으로 파악된다. 이의 개선을 위해서는 전문성을 고려하는 보직이동, 전보범위의 축소, 전보제한기간의 강화 등의 조치가 필요하나, 근본적으로 현재와 같은 과도한 순환보직이 연공서열에 기초한 계급제에 기인하므로 장기적으로 공직분류제도를 계급제에서 직위분류제로 전환하고 실적주의적 요소를 강화해야 할 것이다.

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고분자 제습로터의 저온재생 성능시험 (Performance Test of Low Temperature Regeneration Polymeric Desiccant Rotor)

  • 이진교;이대영;오명도
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.629-632
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    • 2009
  • The polymeric desiccant rotor is made from the super absorbent polymer by ion modification. The moisture sorption capacity of the super desiccant polymer(SDP) is 4 to 5 times larger than those of common desiccant meterials such as silica gel or zeolite. It is also known that SDP can be regenerated even at the relatively low temperature. To fabricate the desiccant rotor, firstly the SDP was laminated by coating the SDP on polyethylene sheet. Then corrugated and rolled up into a rotor. The diameter, the depth, the dimensions of the corrugated channel, etc. were pre-determined from numerical simulation on the heat and mass transfer in the desiccant rotor. The dehumidification performance was tested in a climate chamber. The relevant tests were carried out at the process air inlet temperature of $32^{\circ}C$, the regeneration air inlet temperature of $60^{\circ}C$ and the inlet dew-point temperature of both the process air and the regeneration air of $18.5^{\circ}C$, when the rotation period is long, the moisture sorption is not effective. In the desiccant rotor developed in this study, the optimum rotation period is found about 350s at the regeneration temperature of $60^{\circ}C$. It was found from further experiments that the optimum rotation tends to decreases as the regeneration temperature increases. Meanwhile, the outlet temperature of the process air deceases monotonically as the rotation period increases.

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계단 오르고 내리기시 엉덩관절 내회전이 무릎관절 폄근과 엉덩관절 벌림근 근활성도에 미치는 영향 (Effects of Hip Internal Rotation on Knee Extensor and Hip Abductor Electromyographic Activity During Stair Up and Down)

  • 오재섭;권오윤;이충휘;전혜선
    • 한국전문물리치료학회지
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    • 제15권2호
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    • pp.54-63
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    • 2008
  • The purpose of this study was to examine the effect of the hip internal rotation on knee extensor and hip abductor electromyographic (EMG) activity during stair up and stair down mobility. Eighteen healthy subjects were recruited. All subjects performed stair up and down movements on a step of 30cm height while maintaining the hip in neutral (condition 1) and hip in internal rotation (condition 2). Surface EMG activity was recorded from five muscles (gluteus maximus, vastus lateralis (VL), vastus medialis oblique (VMO), posterior gluteus medius (Gmed), and tensor fascia latae (TFU)) and hip internal rotation angle was measured using a three dimensional motion analysis system The time period for stair up and down was normalized using the MatLab 6.5 program, and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities according to the hip rotation (neutral or internal rotation) during the entire time period of stair up and down in each phase were compared using a paired t-test. During the entire period of stair up, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). During the entire period of stair down, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). However, the EMG activities of the other muscles were not significantly different between the conditions (p>.05). These results suggest that the stair up and down maintaining hip internal rotation was could be a contributing factor on patellar lateral tracking.

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