• Title/Summary/Keyword: TT

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TT&C Antenna Design for LEO Satellite (저궤도 위성용 TT&C 안테나의 설계)

  • Lee, Kwang-Jae;Woo, Duk-Jae;Lee, Taek-Kyung;Lee, Jae-Wook;Lee, Woo-Kyung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.6
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    • pp.642-650
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    • 2010
  • In this paper, we study a TT&C link to obtain a required specifications of TT&C(Telemetry Tracking and Command system) antenna for an LEO(Low Earth Orbit) satellite. The premised mission orbit is the sun-synchronized and circular orbit and it performs earth-space observations. We design minimum TT&C link-budget to obtain required antenna beamwidth and gain. The proposed turnstile antenna provides wide beamwidth and circular polarization. We suggested the attaching position that shows the most effective results by confirming the variation of antenna performance when the proposed antenna is adapted to satellite's various positions. Also we proved the proposed antenna's ability while it is performing the mission through the orbit simulation based on the electrical performance of the proposed turnstile antenna.

A Prospective Study on the Changes of Serum 3,5,3'-Triiodothyronine Levels after Cardiopulmonary bypass in Pediatric Age (소아환자에서 개심술후 혈중 3,5,3'- 삼옥소타이로닌 [triiodothyronine] 농도 변화에 관한 연구)

  • Kim, Yeong-Tae;No, Jun-Ryang
    • Journal of Chest Surgery
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    • v.25 no.11
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    • pp.1209-1217
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    • 1992
  • Triiodothyronine[T3] is an important regulator of the tissue metabolism, and may have potential use as an inotropic agent. The change of serum T3 level was studied in the pediatric age patients after cardiopulmonary by pass. Thyroid function was tested pre-operatively in 33 patients and total triiodothyronine[TT3] levels were serially measured during and after cardiopulmonary bypass[CPB]. After correction of dilutional effect, effects of various factors on the TT3 levels were analyzed. Abrupt fall of TT3 level was demonstrated at 15 minutes after CPB[80.1$\pm$5.9ng/dL] from the initial level of 133.6$\pm$5.3ng/dL, with some recovery at 6 hours[115.4$\pm$6.7ng/dL]. After then, gradual decrease occured reaching to the level of 77.2$\pm$4.2ng /dL at 24 hours. These falls of the TT3 after CPB were statistically significant. [p<0.01 ANOVA] Statistically significant correlation were found between the degree of hemodilution and TT3 concentration at 15 and 30 minutes after CPB[p<0.05]. But, other factors were analyzed to have no effect on TT3 levels. As the degree of the hemodilution increases, TT3 decreased less. This observation probably supports the fact that decrease of TT3 during CPB may be a result of sequestration of T3 into peripheral tissue. Although it was not statistically significant[p=0.08], the fall of TT3 was greater in the group to which plasmanate was added, than those not added. This finding seemed to be due to the increase of albumin and other thyroid-hormone-binding-proteins in the serum. Increase of these binding proteins might potentiate the sequestration of T3 into the liver and the kidney from serum, and as a consequence, decrese the serum TT3 level further.

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Use of the Talk Test for Comparison of Exercise Intensity between Aerobic Activities with Treadmill and Bicycle

  • Kwon, Yonghyun;Chang, Jong Sung
    • The Journal of Korean Physical Therapy
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    • v.32 no.2
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    • pp.132-136
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    • 2020
  • Purpose: The talk test (TT) is an alternative, self-reported method for prescribing and guiding exercise training in both healthy adults and patients with cardiovascular and pulmonary diseases. This study examined whether the TT is a valid tool for evaluating the exercise intensity during two different types of aerobic activity on a treadmill or stationary bicycle in a healthy population. Methods: A total of ten subjects (six males and four females) who had no medical history related to musculoskeletal, cardiovascular, and pulmonary disorders were enrolled in this study. They were evaluated using the TT, which consisted of three-level of difficulties demanding cardiac loads while performing aerobic activities on a treadmill and bicycle ergometer across two consecutive days in a counterbalanced manner. During the activities, the psychophysiological response markers were collected in terms of the heart rate, oxygen saturation, rating of perceived exertion, and metabolic equivalents. Results: Statistical analyses revealed a significant difference in the between-subject variance regarding the TT level effect (p<0.05). On the other hand, no significant findings were detected on the between-group variance(p>0.05) and the TT level×group interaction (p>0.05). The independent t-test indicated no significant differences in heart rate, oxygen saturation, rating of perceived exertion, and metabolic equivalents at any levels of the TT in the two groups. The TT showed a strong correlation with the rating of perceived exertion. Conclusion: This study showed that the TT is a valid and alternative tool for evaluating the aerobic exercise intensity in a healthy population. In addition, differences in the psychophysiological response markers between two aerobic activities, treadmill and bicycle ergometer, were detected in the same exercise intensity scaled with the TT. The TT can be used to evaluate and prescribe the exercise intensity of aerobic activity in cardiovascular and pulmonary physical therapy.

Effectiveness and characteristics of technology transfer consortia in public R&D sector: The case of Korean TT consortia (공공연구부문에서의 기술이전컨소시엄의 효과와 특성 연구: 공공기술이전컨소시엄 사례를 중심으로)

  • Park, Jong-Bok;Ryu, Tae-Kyu
    • Journal of Korea Technology Innovation Society
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    • v.10 no.2
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    • pp.284-309
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    • 2007
  • Technology transfer (TT) consortium is an affiliation of two or more public research institutions (PRIs) that participate in a common technology transfer activity or pool their resources together, with the objective of facilitating technology transfer. Based on empirical analysis of five regional TT consortia (2002-2006) operating in Korea, this paper suggests their effectiveness by employing a TT performance index (TTPI) and identifies possible characteristics involved, such as motivations, facilitators, barriers, and challenges. TTPI devised in the paper is a new composite TT performance index to measure how much the TT performance of a PH changed in a designated year compared to a base year. All the performance indicators of TTPI are well-structured based on the unique TT process that is prevalent in Korea. Further, TTPI can bring different size and focus of PRIs to the same scale for comparison by double-normalizing. The paper tests the effectiveness of TT consortium for the escalation of TT performances in member PRIs by highlighting the differences of TTPI's between 2005 and 2001. As a result, the paper found that the escalation of TTPI for member PRIs was greater than that for non-member PRIs. As for the characteristics of TT consortia, their respective factors obtained by TT expert survey were computed with proportion tests of differences (Z tests) to compare two perspectives between intramural and extramural groups. One of key findings is that there is general homogeneity in stakeholder perspectives regarding motivations, facilitators, barriers, and challenges. Some notable responses are as follow; the most probable motivation to join TT consortium is to share or exchange TT competences for enhanced performance. Second, the most probable facilitator is professional capability of consortium-hired personnel. Third, the foremost probable barriers to effective TT consortium are frequent change of consortium director and passive participation of member PRIs. Lastly, both publicizing TT consortia and developing performance metrics are the most important for the improvement of TT consortia. The understanding of the characteristics of TT consortia increases the likelihood of accelerated success, because TT consortia path from formation to termination encompasses many concepts, processes, principles, and factors. Finally, an analysis of the survey data combined with expert interview and observation data led the authors to derive five conditions as being critical to viable TT consortia in Korea at early stage of technology transfer systems. These conditions include policy infrastructure, proactive participation, excellent professionals, personal motivation, and teaming mechanisms. It is expected that the Korean evidence is a starting point to develop and refine the theory of TT consortia and for additional studies in other countries.

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Touch TT: Scene Text Extractor Using Touchscreen Interface

  • Jung, Je-Hyun;Lee, Seong-Hun;Cho, Min-Su;Kim, Jin-Hyung
    • ETRI Journal
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    • v.33 no.1
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    • pp.78-88
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    • 2011
  • In this paper, we present the Touch Text exTractor (Touch TT), an interactive text segmentation tool for the extraction of scene text from camera-based images. Touch TT provides a natural interface for a user to simply indicate the location of text regions with a simple touchline. Touch TT then automatically estimates the text color and roughly locates the text regions. By inferring text characteristics from the estimated text color and text region, Touch TT can extract text components. Touch TT can also handle partially drawn lines which cover only a small section of text area. The proposed system achieves reasonable accuracy for text extraction from moderately difficult examples from the ICDAR 2003 database and our own database.

Mo 첨가 및 TT 열처리에 따른 합금 690의 부식 특성

  • 전유택;박용수;김영식
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05a
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    • pp.790-795
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    • 1995
  • 합금 600의 대체 재료인 합금 690의 부식 저항성 향상을 위해 스테인리스강 등에서 내식성을 현저히 개선시켜 주는 합금 원소로 알려져 있는 Mo을 첨가하여 TT 열처리를 한 후 부식 특성과 TEM관찰을 행하여 미세 조직의 영향에 대하여 고찰하고자 하였다. TT 처리 시간이 길어짐에 따라 보다 많은 석출물들이 입계에 생성되었으며, Mo을 첨가함에 따라 입계에 탄화물 석출이 지연되었다. 양극 분극 시험, 침지시험, EPR 시험, Huey 시험 결과 소둔재에 비해 TT 처리재의 경우 내식성의 저하는 업었으며 오히려 개선되는 특성을 보였다. 또한 Mo의 함량이 증가함에 따라 탄화물 석출에 걸리는 시간이 길어져 3%의 Mo이 첨가된 합금 690 M2의 경우 예민화 현상은 15시간 TT 처리에서 관찰되었다. 응력 부식 균열 시험 결과 소둔재에 비해 TT 처리재의 응력 부식 균열 저항성이 증가하였으며 Mo의 함량이 증가함에 따라 대체적으로 응력 부식 균열 저항성도 개선되었다.

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두께감소 판형 홀다운스프링 집합체의 탄성강성도 해석

  • 송기남;이진석;서정민;서금석;장흥순
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11b
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    • pp.487-493
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    • 1996
  • 판(leaf)의 너비가 일정하고 두께가 균일하게 감소하는 두께감소 홀다운스프링집합체(Tapered-Thickness Holddown spring Assembly ; TT-HDS)에서 단순 보 이론과 Castigliano의 정리를 이용하여 TT-HDS의 탄성강성도를 해석적으로 구할 수 있도록 종래에 유도되었던 탄성강성도 평가식을 수정하고 확장하였으며 TT-HDS의 기하학적 설계자료를 이용하여 탄성강성도를 평가하였다. 아울러 ANSYS code 의 접촉요소를 이용하여 TT-HDS을 유한요소 모델링하여 탄성강성도를 수치적으로 평가하였다. 평가 결과 전단력 및 축력이 TT-HDS의 탄성강성도에 미치는 영향은 약 0.09∼0.16%정도로서 TT-HDS의 탄성강성도는 주로 굽힘모우멘트에 의해 지배되고 있음이 확인되었다. 또한 접촉요소로 유한요소 모델링하여 평가한 결과는 확장된 평가식으로 평가한 탄성강성도와 매우 잘 일치하고 있음을 발견하였다.

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Effect of leg weight shifting on muscle activation of the trunk and lower extremity during trunk flexion and extension performance

  • Shim, Suyoung;Chung, Yijung
    • Physical Therapy Rehabilitation Science
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    • v.7 no.1
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    • pp.41-47
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    • 2018
  • Objective: To investigate the effect of performing three different toe touch (TT) task condition on the activities of four different muscles using surface electromyography (sEMG) in healthy young adults. Design: Cross-sectional study. Methods: A total of 20 healthy young adults (6 males, 14 females) voluntarily participated in this study. All subject randomly performed three different TT task conditions as follows: general toe-touch (GTT) task, one side toe touch (TT) task during weight bearing, and one side foward toe touch (FTT) task during weight bearing. The muscle activities of erector spinae (ES), gluteus maximus (GM), hamstring (HAM), tibialis anterior (TA) muscles during the TT task were measured using sEMG. Subject performed each of the three conditions three time in random order and mean values were obtained. Results: With the trunk flexion period, the TT and FTT showed significantly greater muscle activity in the GM, HAM and TA compared to the GTT task (p<0.05). The TT position showed significantly greater HAM muscle activity than the GTT position. The dominant and nondominant ES muscle activity was significantly greater in the FTT compared to the GTT position (p<0.05). The dominant GM, HAM, and TA was significantly greater in the TT and FTT compared to the GTT position (p<0.05). Although the dominant ES was significantly greater in the TT and FTT compared to the GTT position (p<0.05), the dominant GM muscle activity was signifcantly greater in the TT compared with the GTT position (p<0.05). Conclusions: These findings may be applicable within the clinical field for selective trunk and lower extremity muscle activation and basic biomechanics purpose.

A Study on the CDMA-based TT&C Design and Experiment Concept

  • Lee, Ho-Jin;Mo, Hee-Sook
    • 제어로봇시스템학회:학술대회논문집
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    • 1999.10a
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    • pp.37-40
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    • 1999
  • ETRI has successfully completed and delivered to KARI the KOMPSAT Mission Control System. This system was designed to work in the conventional TT&C modulation scheme with the pre-assigned frequencies. As a way to accelerate in catching up with future TT&C technology evolutions, a preliminary study needs to be carried out to prepare for the development of a spread spectrum applicable to TT&C. A brief study was carried out to review some points to be considered in designing and implementing spread spectrum schemes to the ground TT&C system intended for a LEO spacecraft. Also a simulation and link design revisit was performed to see the operational and technical benefits with the KOMPSAT TT&C parameters. An experiment concept is proposed to test as many functions at a time once the prototype is developed. In this configuration, a ground-model TT&C transponder is connected via LAN to the ETRI-developed KOMPSAT S/W simulator and linked to the KOMPSAT TM/TC processing s/w via spread spectrum signals through a GEO satellite bent-pipe link. A satellite data relay link simulation could be carried out in this configuration.

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Factors Affecting Tibial Tuberosity-Trochlear Groove Distance in Recurrent Patellar Dislocation

  • Prakash, Jatin;Seon, Jong-Keun;Ahn, Hyeon-Woon;Cho, Kyu-Jin;Im, Chae-Jin;Song, Eun Kyoo
    • Clinics in Orthopedic Surgery
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    • v.10 no.4
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    • pp.420-426
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    • 2018
  • Background: The tibial tuberosity-trochlear groove (TT-TG) distance is used to determine the necessity of tibial tubercle osteotomy. We conducted this study to determine the extent to which each of the tibial tuberosity lateralization, trochlear groove medialization, and knee rotation angle affects the TT-TG distance in both normal and patella dislocated patients and thereby scrutinize the rationale for tuberosity transfer based on the TT-TG distance. Methods: Retrospective analysis of rotational profile computed tomography was done for patella dislocated and control group patients. Femoral anteversion, tibial torsion, knee rotation angle, tuberosity lateralization, and trochlear groove medialization were assessed in all patients. Relationship of these parameters with the TT-TG distance was investigated to evaluate their effects on the TT-TG distance. Results: We observed that the patellar dislocation group, compared to the control group, had increased TT-TG distance (mean, 19.05 mm vs. 9.02 mm) and greater tuberosity lateralization (mean, 64.1% vs. 60.7%) and tibial external rotation in relation to the femur (mean, $7.9^{\circ}$ vs. $-0.81^{\circ}$). Conclusions: Tuberosity lateralization and knee rotation were factors affecting patellar dislocation. These factors should be considered in addition to the TT-TG distance to determine the need for tibial tubercle osteotomy in patients with patellar dislocation.