• 제목/요약/키워드: symmetry key

검색결과 58건 처리시간 0.026초

유방의 해면양 혈관종의 절제 후 보형물을 이용한 즉시 재건 (Immediate Breast Reconstruction after Resection of Cavernous Hemangioma)

  • 김은기;이택종
    • Archives of Plastic Surgery
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    • 제33권5호
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    • pp.577-580
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    • 2006
  • Purpose: Hemangioma of the breast is an infrequent finding and usually encountered incidentally when checking for other disease. Most of hemangiomas of the breast are asymptomatic, not palpable perilobular type. Cavernous hemangioma of the breast is rare and only a few reports about this type of lesion are present. No example has been reported about reconstruction of the breast after resection of large cavernous hemangioma. Methods: We report here a case of immediate breast reconstruction using a Becker implant after subcutaneous mastectomy for a large cavernous hemangioma involving almost entire breast. Results: Symmetry is well maintained after 3 years without deformity or recurrence. Conclusion: The clinical prognosis of breast cavernous hemangioma is good after total excision and reconstruction.

Complementarity and nonlinear structural analysis of skeletal structures

  • Tin-Loi, F.
    • Structural Engineering and Mechanics
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    • 제5권5호
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    • pp.491-505
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    • 1997
  • This paper deals with the formulation and solution of a wide class of structures, in the presence of both geometric and material nonlinearities, as a particular mathematical programming problem. We first present key ideas for the nonholonomic (path dependent) rate formulation for a suitably discretized structural model before we develop its computationally advantageous stepwise holonomic (path independent) counterpart. A feature of the final mathematical programming problem, known as a nonlinear complementarity problem, is that the governing relations exhibit symmetry as a result of the introduction of so-called nonlinear "residuals". One advantage of this form is that it facilitates application of a particular iterative algorithm, in essence a predictor-corrector method, for the solution process. As an illustrative example, we specifically consider the simplest case of plane trusses and detail in particular the general methodology for establishing the static-kinematic relations in a dual format. Extension to other skeletal structures is conceptually transparent. Some numerical examples are presented to illustrate applicability of the procedure.

Effects of Material Anisotropy on Ultrasonic Beam Propagation: Diffraction and Beam Skew

  • Jeong, Hyun-Jo;Schmerr, W.
    • 비파괴검사학회지
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    • 제26권3호
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    • pp.198-205
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    • 2006
  • The necessity of nondestructively inspecting austenitic steels, fiber-reinforced composites, and other inherently anisotropic materials has stimulated considerable interest in developing beam models for anisotropic media. The properties of slowness surface playa key role in the beam models based on the paraxial approximation. In this paper, we apply a modular multi-Gaussian beam (MMGB) model to study the effects of material anisotropy on ultrasonic beam profile. It is shown that the anisotropic effects of beam skew and excess beam divergence enter into the MMGB model through parameters defining the slope and curvature of the slowness surface. The overall beam profile is found when the quasilongitudinal(qL) beam propagates in the symmetry plane of transversely isotropic austenitic steels. Simulation results are presented to illustrate the effects of these parameters on ultrasonic beam diffraction and beam skew. The MMGB calculations are also checked by comparing the anisotropy factor and beam skew angle with other analytical solutions.

AUV hull lines optimization with uncertainty parameters based on six sigma reliability design

  • Hou, Yuan hang;Liang, Xiao;Mu, Xu yang
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제10권4호
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    • pp.499-507
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    • 2018
  • Autonomous Underwater Vehicle (AUV), which are becoming more and more important in ocean exploitation tasks, needs energy conservation urgently when sailing the complex mission path in long time cruise. As hull lines optimization design becomes the key factor, which closely related with resistance, in AUV preliminary design stage, uncertainty parameters need to be considered seriously. In this research, Myring axial symmetry revolution body with parameterized expression is assumed as AUV hull lines, and its travelling resistance is obtained via modified DATCOM formula. The problems of AUV hull lines design for the minimum travelling resistance with uncertain parameters are studied. Based on reliability-based optimization design technology, Design For Six Sigma (DFSS) for high quality level is conducted, and is proved more reliability for the actual environment disturbance.

탄소/탄소 브레이크 디스크의 과도기 열탄성 해석과 3차원 응력해석 (Transient Thermoelastic Analysis and 3 Dimensional Stress Analysis of Carbon/Carbon Brake Disks)

  • 오세희;유재석;김천곤;홍창선;김광수
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2000년도 추계학술발표대회 논문집
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    • pp.147-152
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    • 2000
  • This paper presents the thermoelastic analysis and 3-D failure analysis of the carbon/carbon brake disk. The mechanical properties of the carbon/carbon brake disk were measured for both in-plane and out of plane directions. The mechanical properties were used as the input of the thermoelastic analysis and 3-D stress analysis for the brake disk. The gap between rotor clip and clip retainer was an important parameter in the loading transfer mechanism of the rotor. The change of gap was considered separating the mechanical deformation and thermal deformation. Because the rotor clip and clip retainers were not contacted, the clip retainers and rivets were excluded from the rotor analysis model. The disk was modeled by using the cyclic symmetry condition and the contact problem between the rotor disk and rotor clip was considered. From the results of the 3-D stress analysis, the stress concentration at the key hole of the brake disk was confirmed.

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확률모형과 수식정보를 이용한 와/과 병렬사구 범위결정 (Range Detection of Wa/Kwa Parallel Noun Phrase using a Probabilistic Model and Modification Information)

  • 최용석;신지애;최기선
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제35권2호
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    • pp.128-136
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    • 2008
  • 한국어 구문 분석의 초기 단계로서 병렬구조의 해석은 파싱의 효율을 높일 수 있다. 본 논문은 병렬구조 해석을 위한 비지도식 언어에 독립적인 확률 모델을 제안한다. 이 모델은 병렬구조의 대칭성과 상호교환성에 근거한다. 대칭성은 같은 구조가 반복된다는 것이고, 교환성은 좌우 구성요소를 교환해도 같은 의미를 지닌다는 것이다. 병렬구조는 일반적으로 대칭성을 따르지만, 수식어의 성질에 따라서 한쪽만을 수식하는 비대칭적인 구조가 출현하기도 한다. 비대칭 병렬구조 해석을 위해서 추가적으로 수식관계 통계정보를 사용한다. 제안된 모델을 본 논문에서는 "와/과" 조사로 이루어진 한국어의 명사구 병렬구조를 해석하는데 사용되는 것[1]을 중점으로 보여준다. 지도적 방식에 의한 모델을 포함한 다른 모델들에 비해 효율적임을 실험적으로 보여준다.

한국산 고란초과 식물의 포자 형태 (Spore morphology of Korean Polypodiaceae)

  • 임진아;김철환;곽민주;선병윤
    • 식물분류학회지
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    • 제36권1호
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    • pp.1-19
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    • 2006
  • 한국산 고란초과의 포자 형태를 광학 및 주사현미경으로 관찰하여 기재하고 속검색표를 작성하였다. 포자는 방사상칭의 삼지형인 주걱일엽을 제외하고는 모두 좌우상칭인 단지형이다, perispore는 모든 종에 존재하며 미역고사리속, 일엽초속, 밤일엽속, 주걱일엽속, 창고사리속 및 콩짜개덩굴속은 perispore와 exospore가 서로 유사하지만, 고란초속의 경우는 두터운 perispore에자상 돌기와 두상 돌기가 혼재하여 평활상의 exospore와 차이를 보인다. 석위속의 석위와 애기석위는 perispore와 exospore의 표면무늬가 서로 유사하지만 세뿔석위와 우단일엽은 perispore가 각각 난선상과 유두상 돌기를 가져서 exospore와는 크게 다르다. 그리고 exospore가 추문상의 무늬를 갖는 군은 미역고사리속과 주걱일엽속이며, 일엽초속은 불규칙한 유두상 돌기가 있는 난선상, 고란초속과 창고사리속은 평활상이지만 창고사리속의 경우, 드물게 유두상 돌기도 분포한다. 밤일엽은 미립상 혹은 소형의 유두상 돌기가 밀생하고 콩짜개덩굴은 복잡한 망상무늬를 갖는다. 한편 석위속은 분류군에 따라 유두상 돌기가 있거나 또는 평활상이다.

탄소/탄소 브레이크 디스크의 열탄성 해석과 3차원 응력해석 및 설계 (Thermo-Elastic Analysis, 3-Dimensional Stress Analysis and Design of Carbon/Carbon Brake Disk)

  • 오세희;유재석;김천곤;홍창선;김광수
    • Composites Research
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    • 제15권1호
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    • pp.41-52
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    • 2002
  • 이 논문에서는 탄소/탄소 브레이크 제동중 시스템의 거동을 열탄성 해석을 수행하여 살펴보았고. 파손에 안정적인 디스크의 형상을 찾기 위하여 다양한 형상에 대한 3차원 응력해석을 수행하였다. 탄소/탄소 복합재료의 기계적 물성치가 적층면방향과 두께방향으로 측정되었다. 측정긴 기계적 물성치는 열탄성 해석과 3차원 응력해석을 위한 입력으로 사용 되었다. 로터 클립과 클립 리테이너 사이의 간격은 회전판의 하중전달 미케니즘에 있어서 중요만 인자이다. 간격변화는 기계적 변형과 열 변형으로 분리하여 고려하였다. 클립과 리테이터는 서로 접촉이 발생하지 않았으므로 해석 모델에서 리테이너와 리벳은 제외되었다. 로터 디스크는 반복대칭조건을 사용하여 모델링되었고, 로터 디스크와 로터 클립, 로터 클립과 키 드럼사이의 2중 접촉문제가 고려되었다. 3차인 응력해석의 결과로부터 브레이크 디스크의 키 홀 부분에 응력집중현상이 발생하는 것을 확인하였다. 응력분포는 키 홀 부분에서 접촉면의 회전각과 곡률반경의 변화에 따라 연구 되었다.

Biometry of width between labial transitional line angles in anterior teeth: an observational study

  • Wen, Chao;Ye, Hongqiang;Chen, Hu;Zhou, Yongsheng;Huang, Mingming;Sun, Yuchun
    • The Journal of Advanced Prosthodontics
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    • 제14권1호
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    • pp.1-11
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    • 2022
  • PURPOSE. The maximum width between the mesial and distal labial transitional line angles, described as "esthetic width" herein, could significantly influence the visual perception of the teeth and smile. This study aimed to conduct biometric research on esthetic width and to explore whether regular distribution exists in the esthetic width of human teeth. MATERIALS AND METHODS. A total of 4,264 maxillary and mandibular anterior teeth were measured using the Geomagic studio software program. The proportions of maxillary to mandibular homonymous teeth and proportions between the adjacent teeth were calculated. Bilateral symmetry and the correlation between the esthetic and mesiodistal widths were both accounted for during the measurement procedures. RESULTS. The mean esthetic widths were 6.773 ± 0.518 mm and 4.329 ± 0.331 mm for maxillary and mandibular central incisors, respectively, 5.451 ± 0.487 mm and 5.008 ± 0.351 mm for maxillary and mandibular lateral incisors, respectively, and 3.340 ± 0.353 mm and 5.958 ± 0.415 mm for maxillary and mandibular canines, respectively. Except for the mandibular canines, no significant difference in esthetic width was found among homonymous teeth from the same jaw. A high linear correlation was found between the esthetic and mesiodistal widths of the same tooth, except for the maxillary canines. Esthetic width proportions among different tooth categories showed some regular patterns, which were similar to those of the mesiodistal width. CONCLUSION. Esthetic width is regularly distributed among the teeth in the Chinese population. This could provide an important reference for anterior dental restorations and dimension recovery in esthetic reconstruction of anterior teeth.

A Study on Cooperation between Kerberos system and Credit-Control Server

  • Choi, Bae-Young;Lim, Hyung-Jin;Chung, Tai-Myoung
    • 한국정보기술응용학회:학술대회논문집
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    • 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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    • pp.281-284
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    • 2005
  • Kerberos is system that offer authorization in internet and authentication service. Can speak that put each server between client and user in distributed environment and is security system of symmetry height encryption base that offer authentication base mutually. Kerberos authentication is based entirely on the knowledge of passwords that are stored on the Kerberos Server. A user proves her identity to the Kerberos Server by demonstrating Knowledge of the key. The fact that the Kerberos Server has access to the user's decrypted password is a rwsult of the fact that Kerberos does not use public key cryptogrphy. It is a serious disadvantage of the Kerbercs System. The Server must be physically secure to prevent an attacker from stealing the Kerberos Server and learning all of the user passwords. Kerberos was designend so that the server can be stateless. The Kerberos Server simply answers requests from users and issues tickets. This study focused on designing a SIP procy for interworking with AAA server with respect to user authentication and Kerberos System. Kerberos is security system of encryption base that offer certification function mutually between client application element and server application element in distributed network environment. Kerberos provides service necessary to control whether is going to approve also so that certain client may access to certain server. This paper does Credit-Control Server's function in AAA system of Diameter base so that can include Accounting information that is connected to Rating inside certification information message in Rating process with Kerberos system.

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