• Title/Summary/Keyword: two-mass system

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Argovian Cantonal School in Aarau and Albert Einstein I (칸톤학교 아라우와 아인슈타인 I)

  • Chung, Byung Hoon
    • Journal of The Korean Association For Science Education
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    • v.39 no.2
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    • pp.233-248
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    • 2019
  • This study shows that the Argovian Cantonal School in Aarau, Switzerland, which Albert Einstein attended from 1895 to 1896, had been closely related to the ideological education controversy in German Gymnasium throughout the 19th century. Due to this controversy, Einstein hardly received a formal science education in Bavaria. Despite the lack of formal education in Germany, he had a habit of self-studying from an early age and continued with this practice all through his life. He had a hard time at the authoritarian school in Munich, but at the democratic school in Aarau, where freedom and autonomy were secured, he was able to achieve emotional stability. For a long time, the city Aarau prevailed as a location of tolerance and multi-culturalism, without religious, regional, and national discrimination. This was possible due to the influence of external and unrestricted social mobility, as well as the Enlightenment from France. As a result, this small public school was able to acquire a mass of qualified human resources from outside of Switzerland. As a consequence of the controversy regarding the educational ideology, the Cantonal School adopted practical thoughts and the Enlightenment that fit the spirit of the times. The school consisted of two independent educational organizations: the Gymnasium, where the 'neuhumanistsch' education for the elite training was conducted, and the 'Gewerbeschule', where a more realistic education system was set up to suit the citizen life. In particular, after 1835, the Gymnasium changed gradually from the pure humanistic education to the 'utraquistisch' ways by introducing practical subjects such as natural history. Thereafter, the Cantonal School became an institution that was able to achieve a genuine humanity, academic, and civic life education. Einstein, who attended the 'technische Abteilung' of the 'Gewerbeschule,' considered this school as a role model of an institution that realized true democracy, and that left an unforgettable impression on him.

Biomechanical Analysis of Lower Limb on Stance during Golf Swing (골프 스윙 시 스탠스에 따른 하지의 역학적 분석)

  • Yoon, Se-Jin;Sul, Jeong-Dug;Woo, Byung-Hoon
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.2
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    • pp.532-542
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    • 2021
  • The purpose of this study was to investigate the body's strategy through kinematic variables of the lower extremities and ground reaction forces to maintain the club-head speed and ball accuracy despite the three stances during the golf swing. Ten male golfers who official handicap two were participate in the experiment. All subjects performed swing after maintaining the address posture according to stance conditions(square; SS, open: OS, closed: CS). Using a 3D motion analysis system and force plateform, the results were calculated with the 7-iron full swing each stance. In result, there was no difference in center of displacement, and left and right hip and knee joint angle displacement. Left ankle joint was largely plantar-flexed in OS, and right ankle joint was largely performed in CS from the address to the downswing. From address to take-back, right foot had a large left direction and the left foot had a right direction were greater in OS than in CS. Therefore, despite various stances, maintaining the same posture at impact is thought to have a positive effect on club head speed and ball direction.

LMU Design Optimization for the Float-Over Installation of Floating Offshore Platforms (부유식 해양구조물의 플로트오버 설치용 LMU 최적설계)

  • Kim, Hyun-Seok;Park, Byoungjae;Sung, Hong Gun;Lee, Kangsu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.1
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    • pp.43-50
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    • 2021
  • A Leg Mating Unit (LMU) is a device utilized during the float-over installation of offshore structures that include hyperelastic pads and mating part. The hyperelastic pads absorb the loads, whereas the mating part works as guidance between topside and supporting structures during the mating sequence of float-over installation. In this study, the design optimization of an LMU for the float-over installation of floating-type offshore structures is conducted to enhance the performance and to satisfy the requirements defined by classification society regulations. The initial dimensions of the LMU are referred to the dimensions of those used in fixed-type float-over installation because only the location and the number of LMUs are known. The two-parameter Mooney-Rivlin model is adopted to describe the hyperelastic pads under given material parameters. Geometric variables, such as the thickness, height, and width of members, as well as configuration variables, such as the angle and number of members, are defined as design variables and are parameterized. A sampling-based design sensitivity analysis based on latin hypercube sampling method is performed to filter the important design variables. The design optimization problem is formulated to minimize the total mass of the LMU under maximum von Mises stress and reaction force constraints.

The Effects of Forest Healing Anti-aging Program on Physical Health of the Elderly: A Pilot Study (산림치유 항노화 프로그램이 노인의 신체적 건강에 미치는 효과: 예비연구)

  • Baek, Ji-Eun;Shin, Ho-jin;Kim, Sung-Hyeon;Kim, Jae Yeon;Park, Sujin;Sung, Si-Yoon;Cho, Hwi-young;Hahm, Suk-Chan;Lee, Min-Goo
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.2
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    • pp.81-90
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    • 2021
  • PURPOSE: Aging causes a decrease in muscle mass and a change in posture, which reduces motor function and makes it difficult to perform daily activities independently. As these factors are closely related to the deterioration of the quality of life, it is very important to prevent and manage negative changes in the musculoskeletal system. Forest healing is a nature therapy course that maintains and promotes health using various environmental factors in a forest. The purpose of this study was to identify the effects of the forest healing anti-aging programs on the physical health of the elderly. METHODS: Ten elderly people participated in this study, as part of a forest healing anti-aging program for two days. Functional fitness, muscle strength, gait function, and balance were evaluated before and after the program. RESULTS: The number of arm curls, chair stands, and steps in a 2-min walk significantly increased (p < .05). 8-feet up & go time was significantly decreased (p < .05). Biceps brachii, quadriceps femoris, and calf muscle strength were significantly increased (p < .05). Gait velocity and cadence were significantly increased (p < .05). Step length, stride length, step time, swing time, stance time, and cycle time were significantly decreased (p < .05). Reaching distance in the lateral directions was significantly increased (p < .05). CONCLUSION: The forest healing anti-aging program improves the physical health of the elderly.

Comparison of the Modified Brostrom Repair Technique with and without Augmentation Using Suture Tape for Chronic Ankle Instability (만성 족관절 불안정성을 가진 환자군에서 변형 브로스트롬 술식과 봉합 테이프를 추가한 술식 간의 결과 비교)

  • Gwak, Heui-Chul;Jung, Soo-Hwan;Kim, Jung-Han;Park, Dae-Hyun;Choo, Hye-Jung;Kim, Dae-Yoo
    • Journal of Korean Foot and Ankle Society
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    • v.26 no.1
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    • pp.40-47
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    • 2022
  • Purpose: The modified Broström repair (BR) technique has yielded good outcomes in patients with chronic ankle instability. This study compared clinical and radiological outcomes between two groups of patients who underwent modified BR or lateral ligament augmentation using suture tapes (ST). Materials and Methods: Seventy-seven patients (ST group [n=47], BR group [n=30]; body mass index <26.61 kg/m2; mean age, 30.7±11.0 years [range, 17~39 years]; mean follow-up, 34.0±12.0 months [range, 24~59 months]) were retrospectively reviewed between January 2014 and July 2017. The Foot and Ankle Outcome Score (FAOS), American Orthopedic Foot and Ankle Score (AOFAS), Foot and Ankle Ability Measure (FAAM), visual analogue scale (VAS) score, and Sefton grading system were used for clinical assessment. The talar tilt angle and anterior talar translation were measured using the Telos stress device (Telos GmbH, Marburg, Germany) at 150 N for radiological evaluation. Results: FAOS, AOFAS, FAAM, and VAS scores improved in both groups at final follow-up (ST, 91.1±5.2, 93±2, 88.1±4.5, 1.5±0.7 vs. BR, 91.3±5.4, 93±3, 83.3±4.8, 1.2±0.7, respectively; p=0.854, 0.971, <0.001, 0.04, respectively). According to the FAOS, mean sports activity scores for the ST and BR groups at the final follow-up were 90.3±3.2 and 76.6±4.2, respectively, reflecting superior outcomes in the ST group (p<0.001). Sefton grading revealed satisfactory functional outcomes (ST, 91.5% vs. BR, 90.0%). There was significant improvement in the talar tilt angle and anterior talar translation in both the ST and BR groups (7.6°±1.2°, 10.5±1.8 mm vs. 4.9°±1.1°, 7.9±1.5 mm, respectively; p<0.001). Conclusion: The ST group demonstrated comparable clinical but better improvement in mechanical stability and FAOS sports scores than the BR group.

Effect of Temperature Conditions and Chemical Treatments on Seed Germination of Pseudolysimachion kiusianum var. diamantiacum (Nakai) T.Yamaz. (봉래꼬리풀의 종자 발아에 미치는 온도 조건과 화학적 처리의 영향)

  • Dong-Hak Kim;Young-Eun Kim;Seungju Jo;Jong-Won Lee;Sang-Jun Kim
    • Korean Journal of Plant Resources
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    • v.36 no.4
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    • pp.381-389
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    • 2023
  • The germination characteristics of Pseudolysimachion kiusianum var. diamantiacum (Nakai) T.Yamaz., a rare and endemic plant designated by the Korea Forest Service, were investigated according to light conditions, temperature, and pretreatment. As a result of the germination experiment according to light conditions, it was determined that P. kiusianum is a photoblastic seed that does not germinate at all in dark conditions. The optimum germination temperature of the seeds was found to be 20-25℃, considering the final germination rate and germination time. Three growth regulators (IAA, GA3, kinetin) and two inorganic salts (KNO3, KCl) were pretreated to improve the germination rate of P. kiusianum seeds. The growth regulators IAA and kinetin had no significant effect on improving the germination rate of P. kiusianum seeds. On the other hand, GA3 significantly increased the final germination percentage and germination rate regardless of the concentration, especially the treatment of more than 500 mg·L-1 at 20℃ was more than 4 times more effective than the untreated. The inorganic salts KNO3 and KCl had no significant effect on the seeds of P. kiusianum at low concentrations, but at higher concentrations (40 mM and 300 mM, respectively), they improved the germination rate and germination age by 2 times compared to the untreated. The results of this study will be useful for the mass propagation of P. kiusianum, which has the potential to be utilized as a native plant for restoration.

Clinical Efficacy of Real-Time Sonoelastography for the Follow-Up of Congenital Sternocleidomastoid Muscle Torticollis (선천성 근육성 사경의 추적검사에서 실시간 탄성초음파 검사의 임상적 유용성)

  • Mi ri Jeong;In Sook Lee;Yong Beom Shin;You Seon Song;Sekyoung Park;Jong Woon Song;Jin Il Moon
    • Journal of the Korean Society of Radiology
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    • v.81 no.1
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    • pp.176-189
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    • 2020
  • Purpose To evaluate the clinical efficacy of real-time sonoelastography (RTS) for the follow-up of congenital muscular torticollis, based on measurements of muscle elasticity. Materials and Methods Thirty-four infants (23 male, 11 female) with congenital sternocleidomastoid (SCM) muscle torticollis underwent ultrasonography and elastography between November 2012 and December 2014. We evaluated the thickness, morphology (mass-like, fusiform, or overall thickened shape), and echogenicity of the SCM muscle on grayscale images and color patterns (homogeneous blue, mixed green < 50% and ≥ 50%, and green to red) on elastography. Strain ratios were measured using Q-lab software. A clinician classified the degree of neck rotation and side flexion deficits using a 5-point grade system based on angles of neck rotation and side flexion. Correlations between the ultrasonography and clinical findings were evaluated by statistical analysis. Results Twenty-two infants had right and 12 had left SCM torticollis, respectively. Linear regression analysis showed that involved/contralateral SCM thickness differences, morphology, elasticity color scores, and strain ratios of the affected SCM muscles were significantly correlated with neck rotation and side flexion deficit scores (p < 0.05). The elasticity color score of the affected SCM muscle was the most significant factor. Conclusion RTS might provide a reliable means for evaluating and monitoring congenital muscular torticollis.

Optimum Design of Soil Nailing Excavation Wall System Using Genetic Algorithm and Neural Network Theory (유전자 알고리즘 및 인공신경망 이론을 이용한 쏘일네일링 굴착벽체 시스템의 최적설계)

  • 김홍택;황정순;박성원;유한규
    • Journal of the Korean Geotechnical Society
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    • v.15 no.4
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    • pp.113-132
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    • 1999
  • Recently in Korea, application of the soil nailing is gradually extended to the sites of excavations and slopes having various ground conditions and field characteristics. Design of the soil nailing is generally carried out in two steps, The First step is to examine the minimum safety factor against a sliding of the reinforced nailed-soil mass based on the limit equilibrium approach, and the second step is to check the maximum displacement expected to occur at facing using the numerical analysis technique. However, design parameters related to the soil nailing system are so various that a reliable design method considering interrelationships between these design parameters is continuously necessary. Additionally, taking into account the anisotropic characteristics of in-situ grounds, disturbances in collecting the soil samples and errors in measurements, a systematic analysis of the field measurement data as well as a rational technique of the optimum design is required to improve with respect to economical efficiency. As a part of these purposes, in the present study, a procedure for the optimum design of a soil nailing excavation wall system is proposed. Focusing on a minimization of the expenses in construction, the optimum design procedure is formulated based on the genetic algorithm. Neural network theory is further adopted in predicting the maximum horizontal displacement at a shotcrete facing. Using the proposed procedure, various effects of relevant design parameters are also analyzed. Finally, an optimized design section is compared with the existing design section at the excavation site being constructed, in order to verify a validity of the proposed procedure.

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Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation (부분유방방사선치료(Accelerated Partial Breast Irradiation) 환자의 장액종(Seroma) 체적 변화에 대한 연구)

  • Kim, Dae Ho;Son, Sang Jun;Mun, Jun Ki;Seo, Seok Jin;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.28 no.1
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    • pp.65-75
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    • 2016
  • Purpose : By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Materials and Methods : Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. Results : The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. Conclusion : As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

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Usefulness of Three-Dimensional Maximal Intensity Projection (MIP) Reconstruction Image in Breast MRI (유방자기공명영상에서 3 차원 최대 강도 투사 재건 영상의 유용성)

  • Kim, Hyun-Sung;Kang, Bong-Joo;Kim, Sung-Hun;Choi, Jae-Jeong;Lee, Ji-Hye
    • Investigative Magnetic Resonance Imaging
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    • v.13 no.2
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    • pp.183-189
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    • 2009
  • Purpose : To evaluate the usefulness of three-dimensional (3D) maximal intensity projection (MIP) reconstruction method in breast MRI. Materials and Methods : Total 54 breasts of consecutive 27 patients were examined by breast MRI. Breast MRI was performed using GE Signa Excite Twin speed (GE medical system, Wisconsin, USA) 1.5T. We obtained routine breast MR images including axial T2WI, T1WI, sagittal T1FS, dynamic contrast-enhanced T1FS, and subtraction images. 3D MIP reconstruction images were obtained as follows; subtraction images were obtained using TIPS and early stage of contrast-enhanced TIPS images. And then 3D MIP images were obtained using the subtraction images through advantage workstation (GE Medical system). We detected and analyzed the lesions in the 3D MIP and routine MRI images according to ACR $BIRADS^{(R)}$ MRI lexicon. And then we compared the findings of 3D MIP and those of routine breast MR images and evaluated whether 3D MIP had additional information comparing to routine MR images. Results : 3D MIP images detect the 43 of 56 masses found on routine MR images (76.8%). In non-mass like enhancement, 3D MIP detected 17 of 20 lesions (85 %). And there were one hundred sixty nine foci at 3D MIP images and one hundred nine foci at routine MR images. 3D MIP images detected 14 of 23 category 3 lesions (60.9%), 11 of 16 category 4 lesions (68.87%), 28 of 28 Category 5 lesions (100%). In analyzing the enhancing lesions at 3D MIP images, assessment categories of the lesions were correlated as the results at routine MR images (p-value < 0.0001). 3D MIP detected additional two daughter nodules that were descriped foci at routine MR images and additional one nodule that was not detected at routine MR images. Conclusion : 3D MIP image has some limitations but is useful as additional image of routine breast MR Images.

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