• 제목/요약/키워드: symmetry and asymmetry

검색결과 167건 처리시간 0.046초

What Determines the Laterality of the Chronic Subdural Hematoma?

  • Kim, Byoung-Gu;Lee, Kyeong-Seok;Shim, Jae-Jun;Yoon, Seok-Mann;Doh, Jae-Won;Bae, Hack-Gun
    • Journal of Korean Neurosurgical Society
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    • 제47권6호
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    • pp.424-427
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    • 2010
  • Objective : Chronic subdural hematomas (CSDH) are more common on the left hemisphere than on the right. We verified this left predilection of CSDH and tried to explain the reason for this discrepancy. Methods : We investigated the laterality of CSDH in 182 patients who were treated from January 2005 to December 2009. We examined the symmetry of the cranium and the location of the lesion. Results : CSDH was more common on the left-side. The cranium was symmetric in 63 patients, asymmetric in 119 patients. The asymmetric crania were flat on the right-side in 77 patients, on the left-side in 42 patients. The density of the CSDHs was hypodense in 29 patients, isodense 132 patients, and the others in 21 patients. Bilateral hematomas were more common in the hypodense group. In the right flat crania, the hematoma was more commonly located on the opposite side of the flat side. While in the left flat crania, the hematoma was more common on the same side. Conclusion : CSDHs occurred more frequently on the left side. The anatomical asymmetry of the cranium influences the left predilection of CSDH.

$^{60}Co$ 치료장치의 선원 구동상의 문제점 (Trouble in Source Driving System of a $^{60}Co$ Teletherapy Unit)

  • 강위생
    • Journal of Radiation Protection and Research
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    • 제11권1호
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    • pp.65-69
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    • 1986
  • Picker C-9 $^{60}Co$원격치료장치에 의한 선량분포의 비대칭을 물팬톰에 의한 측정으로부터 발견하고 비대칭적인 선량분포의 원인이 선원의 비정상적인 'ON' 위치였음을 확인하였다. 선원이 비정상적인 위치에서 정지하게 된 원인이 선원을 'OFF'위치로 되돌리는 태엽의 일부 인접면이 접촉하게되어 마찰의 발생과 증대였음을 확인하였다. 태엽에 윤활유를 쳤을 때 선량분포의 대칭성이 다소 호전되었지만 근본적인 해결책은 태엽을 교체하는 것이다. 예방대책으로는 주기적인 선량분포의 측정에 의한 확인과 보수유지계획에 의한 관리가 수행되어야 할 것이다.

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Electron Accumulation in LaAlO3/SrTiO3 Interfaces by the Broken Symmetry of Crystal Field

  • 최희채;박하얀;정용재
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.452-452
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    • 2011
  • Using ab initio calculations, we reveal the origins of the extraordinarily increased electric conductivity of the LaAlO3/SrTiO3 interface. In both of the two (LaAlO3)m/ SrTiO3 heterojunction models (m=3, 5), the oxygen atoms in the cells were displaced toward the n-type interface and the Ti-centered octahedron structure was compressed along the [001] direction by the atomic reconstructions at the (LaAlO3)m/(SrTiO3)4 interfaces. As a result, the 3dxy orbital of the Ti atom was preferentially occupied due to the lowered energy state of the 3dxy orbital, which arises from the crystal field asymmetry. We reason that the extra electrons occupy the 3dxy orbital are accumulated at the interface by the displacement of the oxygen atoms. This accumulation contributes to the conductivity of the n-type interface. In addition, through a comparison of the atomic displacements and charge accumulation amounts between the two thickness models (m=3, 5), the thickness-dependency of the conductivity can be explained.

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일측성 구순열비변형에서 다공성 폴리에틸렌 판을 이용한 상악골이상구증대술 (Augmentation of Pyriform Margin Using Porous High-Density Polyethylene Sheet In Unilateral Cleft Lip Nasal Deformity)

  • 한기환;김진한;최태현;김준형;손대구
    • Archives of Plastic Surgery
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    • 제35권4호
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    • pp.431-438
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    • 2008
  • Purpose: The common deformity after the correction of unilateral cleft lip nasal deformity is nasal asymmetry, and it is caused by the hypoplasia of the pyriform aperture. To correct this, many procedures have been applied, but still many problems are present. Authors performed the inlay and onlay insertion of porous high density polyethylene sheet(1 mm thickness $Medpor{(R)}$ sheet) in the hypoplastic pyriform margin of cleft side and obtained satisfactory results. Methods: 11 cases were performed and the mean follow up period was 15.1 months. Their mean age was 23.6 years. Under general anesthesia, bilateral pyriform margin was exposed. $Medpor{(R)}$ sheets in "match stick" like shaped were inlay inserted, and kidney shaped were onlay inserted fixating with two 6 mm titanium screws. After the surgery, the results was evaluated by photogrammetric analysis. On the basal view, the distance from the subalare and labiale superius' to the transverse baseline connecting the both cheilions was measured from the cleft side and the non-cleft side. Then, the postoperative symmetry was assessed by obtaining the cleft side against the non-cleft side as proportion index, defined as lateral and medial upper lip contour index. Results: There were 2 infections. The cause was because the inserted implant was too long and thus protruded to the base of nasal cavity. The lateral upper lip contour index was from 95.49 to 103.27, and medial upper lip contour index was from 90.92 to 100.49, it was statistically increased, and thus the symmetry was improved. However clinically mild depression remained at nostril floor. Conclusion: Authors performed porous high density polyethylene sheet inlay and onlay insertion for the hypoplasia of the pyriform margin in unilateral cleft lip nasal deformity. It was found that depressed pyriform margin and upper lip were corrected effectively except for the nostril floor, for which an additional soft tissue augmentation would be necessary. The inlay insertion has risk of protrusion, thus the guideline of the use of artificial prosthesis should be observed strictly.

파킨슨병 환자의 상지 스윙의 비대칭과 청각신호에 따른 보행 시 진폭에 미치는 영향 (Arm Swing Asymmetry and Effect of Auditory Cues on Amplitude in the Patients with Parkinson's Disease)

  • 손호희;김은정
    • 한국산학기술학회논문지
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    • 제14권1호
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    • pp.344-350
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    • 2013
  • 본 연구의 목적은 파킨슨병 환자의 청각 신호에 따른 보행 시, 상지 스윙의 비대칭과 진폭에 미치는 영향을 알아보기 위함이다. 연구의 대상자는 초기 파킨슨병으로 진단받은 14명의 환자로, 청각 신호(빠른 속도, 일반적인 속도, 느린 속도)를 무작위 순서로 제공하여 보행을 실시하였다. 청각 신호 속도는 전자 메트로놈을 이용하여 대상자의 자연스러운 보행 속도보다 ${\pm}20%$ 속도를 적용하였다. 각각의 속도에 따른 청각 신호를 적용한 보행을 실시하는 동안, 동작분석기를 사용하여 보행 시 상지 스윙의 운동학적 변수를 비교 분석하였다. 정상 속도의 보행 시 파킨슨병 환자의 양측 상지 스윙 진폭의 비교에서는 더 많은 영향을 받은 쪽(MAS)의 상지 스윙 진폭에서 유의한 감소가 나타났다(p<.05). 청각 신호 속도에 따른 보행 시의 비교에서는 빠른 속도의 청각 신호를 적용한 보행 시 상지 스윙의 유의한 증가가 나타났다(p<.05). 본 연구의 결과를 통해 파킨슨 환자의 보행 시 양측 상지 스윙의 비대칭을 확인할 수 있었으며 또한 보행 시 빠른 청각 신호를 적용하는 경우, 파킨슨병 환자의 상지 스윙을 증가시켜 자연스러운 보행양상을 유도할 수 있으므로 중재 시 필요에 따라 적절한 속도의 청각 신호를 적용하여 보행훈련에 적용할 수 있을 것으로 생각된다.

Effects of Isometric Exercise on Muscle Activity and Body Balance Ability in Asymmetrical Walkers

  • Young Ae, KWON;Mun Young, HEO;Jeong Weon, KIM;Hwang Woon, MOON
    • Journal of Sport and Applied Science
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    • 제7권1호
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    • pp.21-29
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    • 2023
  • Purpose: This study was to investigate the effects of isometric exercise on muscle activity and body balance ability in asymmetrical walkers. Research design, data, and methodology: Twenty gait asymmetry people were divided to unilateral exercise group (UG, n=10) and bilateral exercise group (BG, n=10). UG were performed unilateral exercise for 60 minutes, three times a week, and 16 weeks, and BG were performed one side and then the other side alternately for 60 minutes, three times a week, and 16 weeks. Muscle activity and body balance ability were measured before, after 4 and 16 weeks isometric exercise. Moreover, SI (symmetry index; SI) was calculated from the measured value of SL (step length). Statistical analyses were conducted using one-way ANOVA and two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Scheffe. Results: In the muscle activity, ST decreased significantly in short step length(S-SL) and BG of LS compared to before isometric exercise(p<.05), and GCM decreased significantly in BG of S-SL(p<.05). As for body balance ability, the mSEBT-A difference between L-SL and S-SL was decreased significantly in UG(p<.05). And the respective total scores of L-SL and S-SL, mSEBT-PM and mSEBT-PL were increased significantly in BG(p<.05). Conclusions: As a result, in this study above, it was confirmed that isometric exercise improved muscle activity and body balance ability in asymmetrical walkers.

Opportunistic Relay Selection for Joint Decode-and-Forward Based Two-Way Relaying with Network Coding

  • Ji, Xiaodong;Zheng, Baoyu;Zou, Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권9호
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    • pp.1513-1527
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    • 2011
  • This paper investigates the capacity rate problems for a joint decode-and-forward (JDF) based two-way relaying with network coding. We first characterize the achievable rate region for a conventional three-node network scenario along with the calculation of the corresponding maximal sum-rate. Then, for the goal of maximizing the system sum-rate, opportunistic relay selection is examined for multi-relay networks. As a result, a novel strategy for the implementation of relay selection is proposed, which depends on the instantaneous channel state and allows a single best relay to help the two-way information exchange. The JDF scheme and the scheme using relay selection are analyzed in terms of outage probability, after which the corresponding exact expressions are developed over Rayleigh fading channels. For the purpose of comparison, outage probabilities of the amplify-and-forward (AF) scheme and those of the scheme using relay selection are also derived. Finally, simulation experiments are done and performance comparisons are conducted. The results verify that the proposed strategy is an appropriate method for the implementation of relay selection and can achieve significant performance gains in terms of outage probability regardless of the symmetry or asymmetry of the channels. Compared with the AF scheme and the scheme using relay selection, the conventional JDF scheme and that using relay selection perform well at low signal-to-noise ratios (SNRs).

현대 구조적 패션디자인에 나타난 구조미의 표현방식에 대한 연구 - 산티아고 칼라뜨라바의 건축특성을 중심으로 - (A study on expression methods for structural aesthetics in modern fashion design - Focus on the architectural characteristics of Santiago Calatrava -)

  • 이연지;엄소희
    • 복식문화연구
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    • 제23권5호
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    • pp.737-754
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    • 2015
  • The structural aesthetics of architecture are becoming an inspirational source for many fashion designers and have been reborn in structural fashion. This study planned to analyze the method of expression of structural aesthetics expressed in modern structural fashion design and the construction method to maximize such an effect on the basis of the construction characteristic of Santiago Calatrava as the representative architect of the structural aesthetic. According to the study, the structural aesthetics expressed in modern structural fashion design are as follows: 1) The symbolical formative aesthetic expressed by symbolical inference and analyzation; 2) the dynamic beauty of physic expressed by visual emphasis and dynamics; and 3) the asymmetric beauty of symmetry expressed by metastasis toward the boundary between balance and imbalance. In addition, to maximize structural aesthetics, we used repetition and a progressive technique based on rhythm, asymmetry, and incision-based variances, such as balance, polygon flux, and inference, and analyzation-based distortion as the structuring principle. The following expression methods for maximizing structural aesthetics were found: 1) symbolical and structural exaggeration of appearance; 2) detail technique expansion and material property diversification; and 3) the three-dimensional transformation of structure and shell expression. Structural fashion design was found to have maximized structural aesthetics by using such expression methods to secure artistic esthetics, destroy existing shapes and patterns, and create unique shapes.

Objective photographic assessments and comparisons of immediate bilateral breast reconstruction using deep inferior epigastric perforator flaps and implants

  • Han, Hyun Ho;Choi, Jin Mi;Eom, Jin Sup
    • Archives of Plastic Surgery
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    • 제48권5호
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    • pp.473-482
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    • 2021
  • Background The increasing number of bilateral breast cancer patients has been accompanied by a growing need for bilateral mastectomy with immediate reconstruction. However, little research has investigated the complications and aesthetic outcomes related to bilateral reconstruction. Therefore, we analyzed retrospective data comparing the outcomes of bilateral reconstruction using deep inferior epigastric perforator (DIEP) flaps or implants. Methods This study included 52 patients (24 DIEP group and 28 implant group) who underwent bilateral mastectomy with immediate reconstruction between 2010 and 2020. Patient demographics, surgical characteristics, and complications were recorded. The difference between the left and right position of the nipple-areolar complex with respect to the sternal notch point at the clavicle was measured, and breast symmetry was evaluated. Results The average weight of breasts reconstructed with DIEP flaps (417.43±152.50 g) was higher than that of breasts with implants. The hospitalization period and operation time were significantly longer in the DIEP group. Early complications were significantly more common in the implant group (36.53%) than in the DIEP group. The angles between the nipples and the horizontal line were 1.09°±0.71° and 1.75°±1.45° in the DIEP and implant groups, respectively. Conclusions Although the surgical burden is lower, breast reconstruction using implants requires greater attention with respect to implant positioning, asymmetry, and complications than DIEP flap reconstruction. DIEP flap reconstruction has a prolonged operation time and a high risk of flap failure, but yields excellent cosmetic results and does not require intensive follow-up. Patients should be consulted to determine the most suitable option for them.

정복 시기가 지난 안면골 골절의 수술적 교정 (Delayed Reduction of Facial Bone Fractures)

  • 이규섭;박재범;송승한;오상하;강낙헌
    • 대한두개안면성형외과학회지
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    • 제14권2호
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    • pp.119-123
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    • 2013
  • Except for special situations, it is generally agreed that best results in the treatment of facial fractures is expected if reduction is done within the first 2 or 3 weeks after injury. We reduced facial bone fractures at 4 to 7 weeks after trauma. A 44-year-old female patient underwent open reduction for her right zygomaticomaxillary complex fracture at 7 weeks after injury. A 59-year-old female patient underwent surgery for the right mandible body and left parasymphysis fractures at 4 weeks after injury. Using traditional approaches, granulation tissue and callus were removed from the fracture sites, and malunited fracture lines were separated by a small osteotome. We reduced the displaced fractured zygoma and mandible to their normal anatomical positions and fixed them using titanium plates. No complications such as asymmetry, malunion, malocclusion, or trismus were seen. Unfavorable asymmetric facial contours were corrected, and we obtained good occlusion with favorable bony alignment. The functional and aesthetic outcomes were satisfactory. Through removal the callus and limited osteotomy, a successful approach to the previously fractured line was possible, and an exact correction with symmetry was obtained. This method can be a good option for obtaining good mobility and clinical results in treating delayed facial bone fractures.