• Archives of Reconstructive Microsurgery
• /
• 제9권2호
• /
• pp.172-178
• /
• 2000

With esthetic concern in the reconstruction of skin and soft tissue defects of face, the use of local flap has been the method of choice. However, when there is extensive tissue loss in the face, local flaps do not provide satisfactory results. The amazing development of microsurgical technique has decreased the percentage of free flap failure, thus making free flap use in reconstruction of facial soft tissue defects. Many free flaps has been applied for reconstruction of face defects. Especially, the radial forearm flap has numerous advantages with which facial reconstruction is made possible. But, its disadvantages are ; the sacrifice of one major artery supplying the hand and donor site complications. In order to circumvent these disadvantages, we employed posterior interosseous artery(PIA) forearm free flap for the reconstruction of the face defects. The posterior interosseous forearm island flap was first described by Zancolli and Angrigiani(1985). Currently, the PIA island flap and free flap have been used for hand reconstructions. The disadvantages of the PIA flap are ; the small caliber of the pedicle, different locations of the perforating branches, and the proximity of the motor branch of the radial nerve. But, its advantages lies in preserving the major artery of the hand, minimal donor site morbidity, and fairly well matched skin texture and color, and that the flap volume is sufficient, not too bulky with convenient handling. By using this flap, we performed 1 case of tumor resection and 1 case of traumatic defect. From our experiences we conclude that it is one of many useful methods in the reconstruction of the skin and soft tissue defects of the face. We also have discussed advantages and some limitations of various free flaps for reconstruction of the face.

• Journal of Information Processing Systems
• /
• 제8권3호
• /
• pp.483-494
• /
• 2012

Many recent events, such as terrorist attacks, exposed defects in most sophisticated security systems. Therefore, it is necessary to improve security data systems based on the body or behavioral characteristics, often called biometrics. Together with the growing interest in the development of human and computer interface and biometric identification, human face recognition has become an active research area. Face recognition appears to offer several advantages over other biometric methods. Nowadays, Principal Component Analysis (PCA) has been widely adopted for the face recognition algorithm. Yet still, PCA has limitations such as poor discriminatory power and large computational load. This paper proposes a novel algorithm for face recognition using a mid band frequency component of partial information which is used for PCA representation. Because the human face has even symmetry, half of a face is sufficient for face recognition. This partial information saves storage and computation time. In comparison with the traditional use of PCA, the proposed method gives better recognition accuracy and discriminatory power. Furthermore, the proposed method reduces the computational load and storage significantly.

• Archives of Plastic Surgery
• /
• 제39권6호
• /
• pp.619-625
• /
• 2012

Background After skin tumor excision on the face, extremities, or trunk, the choice of treatment for a skin defect is highly variable. Many surgeons prefer to use a local flap rather than a skin graft or free flap for small- or moderately-sized circular defects. We have used unilateral or bilateral V-Y advancement flaps, especially on the face. Here we evaluated the functional and aesthetic results of this technique. Methods All of the patients were pathologically diagnosed with squamous cell carcinoma (SCC), basal cell carcinoma (BCC), or malignant melanoma or premalignant lesion (Bowen's disease). Thirty-two patients underwent V-Y advancement flap repair (11 unilateral and 21 bilateral) from January 2007 to June 2011. We analyzed the patients' age and satisfaction, and location and size of defect. The patients were followed up for 6 months or more. Results There were 22 women and 10 men. The ages ranged from 47 to 93 years with a mean age of 66 years. The causes were SCC in 15 cases, BCC in 13 cases, malignant melanoma in 1 case, Bowen's disease in 2 cases, and another cause in 1 case. The tumor locations were the face in 28 patients, and the scalp, upper limb, and flank each in one patient. All of the flaps survived and the aesthetic results were good. Postoperative recovery was usually rapid, and no complication or tumor recurrence was observed. Conclusions The V-Y advancement flap is often used not only for facial circular defects but also for defects of the trunk and extremities. Its advantages are less scarring and superior aesthetic results as compared with other local flap methods, because of less scarification of adjacent tissue and because it is an easy surgical technique.

• 제어로봇시스템학회논문지
• /
• 제4권6호
• /
• pp.795-801
• /
• 1998

In this paper, we propose a machine vision algorithm for inspecting inserts which are used for milling and turning operations. Major defects of the inserts are breakage and crack on insert surfaces. Among the defects, breakages on the face of the inserts can be detected through three stages of the algorithm developed in this paper. In the first stage, a multi-layer perceptron is used to recognize the inserts being inspected. Edge detection of the insert image is performed in the second stage. Finally, in the third stage breakages on the insert face are identified using Hough transform. The overall algorithm is tested on real specimens and the results show that the algorithm works fairly well.

• 대한의사협회지
• /
• 제61권12호
• /
• pp.724-731
• /
• 2018

Our faces can express a remarkable range of subtle emotions and silent messages. Because the face is so essential for complex social interactions that are part of our everyday lives, aesthetic repair and restoration of function are an important tasks that we must not take lightly. Soft-tissue defects occur in trauma patients and require thorough evaluation, planning, and surgical treatment to achieve optimal functional and aesthetic outcomes, while minimizing the risk of complications. Recognizing the full nature of the injury and developing a logical treatment plan help determine whether there will be future aesthetic or functional deformities. Proper classification of the wound enables appropriate treatment, and helps predict the postoperative appearance and function. Comprehensive care of trauma patients requires a diverse breadth of skills, beginning with an initial evaluation, followed by resuscitation. Traditionally, facial defects have been managed with closure or grafting, and prosthetic obturators. Sometimes, however, large defects cannot be closed using simple methods. Such cases, which involve exposure of critical structures, bone, joint spaces, and neurovascular structures, requires more complex treatment. We reviewed and classified causes of significant trauma resulting in facial injuries that were reconstructed by microsurgical techniques without simple sutures or coverage with partial flaps. A local flap is a good choice for reconstruction, but large defects are hard to cover with a local flap alone. Early microsurgical reconstruction of a large facial defect is an excellent choice for aesthetic and functional outcomes.

• 한국결정성장학회지
• /
• 제24권5호
• /
• pp.196-201
• /
• 2014

화학적 습식 에칭을 통해 AlN와 GaN의 결함 및 표면 특성을 분석했다. 화학적 습식 에칭은 단결정의 결함을 선택적으로 에칭하기 때문에 결정의 품질을 평가하는 좋은 방법으로 주목 받고 있다. AlN와 GaN의 단결정은 NaOH/KOH 용융액을 이용하여 에칭을 했으며, 에칭 후 표면 특성을 알아보기 위해 주사전자현미경(SEM)과 원자힘 현미경(AFM)을 촬영했다. 에치 핏의 깊이를 측정하여 표면에 따른 에칭 속도를 계산했다. 그 결과 AlN와 GaN 표면에는 두 개의 다른 형태에 에치 핏이 형성 되었다. (0001)면의 metal-face(Al, Ga)는 육각 추를 뒤집어 놓은 형태를 갖는 반면 N-face는 육각형 형태의 소구 모양(hillock structure)을 하고 있었다. 에칭 속도는 N-face가 metal-face(Al, Ga)보다 각 각 약 109배(AlN)와 5배 정도 빨랐다. 에칭이 진행되는 동안 에치 핏은 일정한 크기로 증가하다 서로 이웃한 에치 핏들과 합쳐지는 것으로 보여졌다. 또한 AlN와 GaN의 에칭 공정을 화학적 메커니즘을 통해 알아 보았는데, 수산화 이온($OH^-$)과 질소의 dangling bond에 영향을 받아 metal-face(Al, Ga)와 N-face가 선택적으로 에칭되는 것으로 추론되었다.

• 한국세라믹학회지
• /
• 제27권4호
• /
• pp.447-456
• /
• 1990

ZnWO4 single crystals were grown by Czochralski method. And the orientation of grown crystals were determined by Laue back reflection, and the crystals were siliced at (100), (010), (001) face before polishing. The morphologys and distribution of etch pits on each face were observed by optical microscopy. In the present study, we understood that dislocation distributjioon rely on shape of solid-liquid interface, and secondary phase acts on the dislocation source. We also observed dislocation trace(etch pits) of (100) slip plane on (010) cleavage plane.

• 한국조경학회지
• /
• 제29권2호
• /
• pp.61-67
• /
• 2001

The purpose of this thesis was to provide the basic data for landscape architecture of apartment constructions and to minimize the users´ and builder´ loss in terms of finance and landscape due to defects in planting. After a review of literature related to defects of planting work, the researcher investigated the defects in planting of landscape plants on the basis of data from the drawing and defect-repair construction of 50 civil apartment complexes in Daegu and Kyongbook are from 1994 to 1998. The defect-ratio was analysed in terms of the species, shapes, and sizes of trees. It provides matters for consideration in terms of the design of the landscape planting on the apartment unit. It also provided the future directions for landscape architecture in apartment constructions with regard to the selection of the planting trees, etc., given statistics on defect occurrence. The causes of defect of the landscape planting trees were not studied accurately in this study due to the board range of researched area, the differences of the planting ground environment, the management ability, and the parameters of judging planting defects. It is recommended that those areas should be researched in the future.

• 대한두개안면성형외과학회지
• /
• 제11권1호
• /
• pp.13-18
• /
• 2010

Purpose: Nasal defect can be caused by excision of tumor, trauma, inflammation from foreign body reaction. Nose is located in the middle of face and protruded, reconstruction should be done in harmony with size, shape, color, and textures. We report various methods of nasal reconstruction using local flaps. Methods: From March 1998 to July 2008, 36 patients were operated to reconstruct the nasal defects. Causes of the nasal defects were tumor (18 cases), trauma (11 cases), inflammation from foreign body reaction (5 cases) and congenital malformation (2 cases). The sites of the defects were ala (22 cases), nasal tip (8 cases) and dorsum (6 cases). The thickness of the defects was skin only (5 cases), dermis and cartilagenous layer (7 cases) and full-thickness (24 cases). According to the sites and thickness of the defects, various local flaps were used. Most of alar defects were covered by nasolabial flaps or bilobed flaps and the majority of dorsal and tip defects were covered by paramedian forehead flaps. Small defects below $0.25 cm^2$ were covered with composite graft or full-thickness skin graft. Results: The follow-up period was 14 months. Partial flap necrosis was observed in a case, and one case of infection was reported, it was improved by wound revision and antibiotics. Nasal reconstruction with various local flaps could provide satisfactory results in terms of color and texture match. Conclusion: The important factors of nasal reconstruction are the shape of reconstructed nose, color, and texture. Nasolabial flap is appropriate method for alar or columellar reconstruction and nasolabial island flap is suitable for tip defect. The defect located lateral wall could be reconstructed with bilobed flap for natural color and texture. Skin graft should be considered when the defect could not afford to be covered by adjacent local flap. And entire nasal defect or large defect could be reconstructed by paramedian forehead flap.

• 대한두개안면성형외과학회지
• /
• 제22권4호
• /
• pp.183-192
• /
• 2021

Background: The purse-string suture (PSS) is a simple and rapid wound closure method that results in minimal scarring. It has been used to treat circular or oval skin defects caused by tumor excision or trauma. However, due to obscurity, it is not widely used, especially for the head and neck. This study aimed to modify the PSS to obtain predictable and acceptable results. Methods: A total of 45 sites in 39 patients with various types of skin and soft tissue defects in the head and neck were treated with PSS. We used PDS II (2-0 to 5-0), which is an absorbable suture. Minimal dissection of the subcutaneous layer was performed. The suture knot was hidden by placing it in the dissection layer. Depending on the characteristics of the skin and soft tissue defects, additional surgical interventions such as side-to-side advancement sutures, double PSS, or split-thickness skin graft were applied. Results: All wounds healed completely without any serious complications. Large defects up to 45 mm in diameter were successfully reconstructed using only PSS. Postoperative radiating folds were almost flattened after approximately 1-2 months. Conclusion: PSS is simple, rapid, and relatively free from surgical design. Owing to the circumferential advancement of the surrounding tissue, PSS always results in a smaller scar than the initial lesion and less distortion of the body structures around the wound in the completely healed defect. If the operator can predict the process of healing and immediate radiating folds, PSS could be a favorable option for round skin defects in the head and neck.