• Title/Summary/Keyword: cause of defects

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A Study on Software Fault Analysis and Management Method using Defect Tracking System (결함 추적 시스템에 의한 소프트웨어 결함 분석 및 관리기법 연구)

  • Joon, Moon-Young;Yul, Rhew-Sung
    • The KIPS Transactions:PartD
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    • v.15D no.3
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    • pp.321-326
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    • 2008
  • The software defects that are not found in the course of a project frequently appear during the conduct of the maintenance procedure after the complete development of the software. As the frequency of surfacing of defects during the maintenance procedure increases, the cost likewise increases, and the quality and customer reliability decreases. The defect rate will go down only if cause analysis and process improvement are constantly performed. This study embodies the defect tracking system (DTS) by considering the Pareto principle: that most defects are repetitions of defects that have previously occurred. Based on the records of previously occurring defects found during the conduct of a maintenance procedure, DTS tracks the causes of the software defects and provides the developer, operator, and maintenance engineer with the basic data for the improvement of the software concerned so that the defect will no longer be manifested or repeated. The basic function of DTS is to analyze the defect type, provide the measurement index for it, and aggregate the program defect type. Doing these will pave the way for the full correction of all the defects of a software as it will enable the defect correction team to check the measured defect type. When DTS was applied in the software configuration management system of the W company, around 65% of all its software defects were corrected.

Development of Digital-Image-Correlation Technique for Detecting Internal Defects in Simulated Specimens of Wind Turbine Blades (풍력 블레이드 모의 시편의 내부 결함 검출을 위한 이미지 상관법 기술 개발)

  • Hong, Kyung Min;Park, Nak Gyu
    • Korean Journal of Optics and Photonics
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    • v.31 no.5
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    • pp.205-212
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    • 2020
  • In the performance of a wind turbine system, the blades play a vital role. However, they are susceptible to damage arising from complex and irregular loading (which may even cause catastrophic collapse), and they are expensive to maintain. Therefore, it is very important both to find defects after blade manufacturing is completed and to find damage after the blade is used for a certain period of time. This study provides a new perspective for the detection of internal defects in glass-fiber- and carbon-fiber-reinforced panels, which are used as the main materials in wind turbine blades. A gap or fracture between fiber-reinforced materials, which may occur during blade manufacturing or operation, is simulated by drilling a hole 5 mm in diameter in the middle layer of the laminated material. Then, a digital-image-correlation (DIC) method is used to detect internal defects in the blade. Tensile load is applied to the fabricated specimen using a tensile tester, and the generated changes are recorded and analyzed with the DIC system. In the glass-fiber-reinforced laminated specimen, internal defects were detected from a strain value of 5% until the end of the experiment, while in the case of the carbon-fiber-reinforced laminated specimen, internal defects were detected from 1% onward. It was proved using the DIC system that the defect was detected as a certain level of strain difference developed around the internal defects, according to the material properties.

The Usability of Various Flaps for Hindfoot Reconstruction (다양한 피판술을 이용한 후족부 연부조직의 결손)

  • Lee, Jung-Hwan;Lee, Jong-Wook;Koh, Jang-Hyu;Seo, Dong-Kook;Choi, Jai-Koo;Oh, Suk-Jun;Jang, Young-Chul
    • Archives of Plastic Surgery
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    • v.37 no.2
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    • pp.129-136
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    • 2010
  • Purpose: Anatomically, the foot is provided with insufficient blood supply and is relatively vulnerable to venous congestion compared to other parts of the body. Soft tissue defects are more difficult to manage and palliative treatments can cause hyperkeratosis or ulcer formation, which subsequently requires repeated surgeries. For weight bearing area such as the heel, not only is it important to provide wound coverage but also to restore the protective senses. In these cases, application of flaps for hind foot reconstruction is widely recognized as an effective treatment. In this study, we report the cases of soft tissue reconstruction for which various types of flaps were used to produce good results in both functional and cosmetic aspects. Methods: Data from 37 cases of hind foot operation utilizing flaps performed between from June 2000 to June 2008 were analyzed. Results: Burn related factors were the most common cause of defects, accounting for 19 cases. In addition, chronic ulceration was responsible for 8 cases and so forth. Types of flaps used for the operations, listed in descending order are radial forearm free flap (18), medial plantar island flap (6), rotation flap (5), sural island flap (3), anterolateral thigh free flap (2), lattisimus dorsi muscular flap (2), and contra lateral medial plantar free flap (1). 37 cases were successful, but 8 cases required skin graft due to partial necrosis in small areas. Conclusion : Hind foot reconstruction surgeries that utilize flaps are advantageous in protecting the internal structure, restoring functions, and achieving proper contour aesthetically. Generally, medial plantar skin is preferred because of the anatomical characteristics of the foot (e.g. fibrous septa, soft tissue for cushion). However alternative methods must be applied for defects larger than medial plantar skin and cases in which injuries exist in the flap donor / recipient site (scars in the vicinity of the wound, combined vascular injury). We used various types of flaps including radial forearm neurosensory free flap in order to reconstruct hind foot defects, and report good results in both functional and cosmetic aspects.

Clinical Evaluation of 70 Cases of Ventricular Septal Defect in Korea (심실 중격결손증에 대한 임상적 고찰 [70예])

  • 조규석
    • Journal of Chest Surgery
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    • v.11 no.1
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    • pp.46-57
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    • 1978
  • Ventricular septal defect was the most common congenital Heart disease admitted to the Severance Hospital from December, 1963 to June 30. 1977. A total of 1,811 cardiac patients received cardiac catheterization in the CardiacCenter of Yonsei University Medical College. Out of the 1,811 cardiac patients, 791 cases had congenital heart disease and of these 172 cases had ventricular septal defect. This amounted to 21.7% of all those with congenital heart disease. Seventy cases of ventricular septal defect operated on in the chest surgery department are presented. Of these 70 cases of ventricular septal defect, 54 cases were male and 16 cases were female. Their ages ranged from 4/12 months to 32 years. The ratio of systolic pressure of the main pulmonary to systemic artery [Pp/Ps] for 29 of the 59 isolated ventricular septal defects was below 45 percent. Pp/Ps ratio for 19 of the 59 isolated ventricular septal defects was 75 percent. The patients were mostly below fifteen years of age. Out of 64 cases, there were 36 cases of type II defects, 20 cases of type I, 4 cases of type III , 2 cases of type IV, one case of both type II and one case of left ventricular right atrial communication. The anomalies associated with ventricular septal defect were 13 in all; 4 cases of aortic insufficiency, 3 cases of ruptured aneurysm of the sortie sinus of valsalva, 2 cases of ruptured aneurysm of the sortie sinus of valsalva with aortic insufficiency, 2 cases of patent ductus arteriosus, one case of ruptured aneurysm of the aortic sinus of valsalva with atrial septal defect [secundum type] and one case of atrial septal defect [secundum type]. Overall mortality was 8.6 percent. The mortality in pulmonary artery banding was 37.5 percent. The causes of mortality were in one case congestive heart failure, in one case asphyxia and in one case respiratory insufficiency. Tile mortality in ventricular septal defect associated with pulmonary hypertension was 7.1 percent. The cause of mortality was in one case low cardiac output syndrome. There was no mortality in the ventricular septal defects without pulmonary hypertension and mortality in the ventricular septal defect. In ventricular septal defect associated with combined anomalies, the causes mortality were in one case respiratory insufficiency and in one case congestive heart failure.

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Sural Artery Flap for the Treatment of Soft Tissue Defects around Knee Joint (비복 동맥 피판을 이용한 슬관절 주위의 연부 조직 결손의 치료)

  • Bae, Kee Jeong;Lee, Young Ho;Kim, Min Bom;Lee, Hyuk Jin;Kwon, Ji Eun;Baek, Goo Hyun
    • Archives of Reconstructive Microsurgery
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    • v.21 no.2
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    • pp.143-148
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    • 2012
  • Purpose: This report presents the authors' experience of twelve patients with sural artery flap for soft tissue defects around the knee joint. Materials and Methods: The patients' age ranged from 25 to 80 years; seven of the patients were male and five were female. The cause of soft-tissue defects involved wide excision for malignant soft tissue tumor, tumor prosthesis related infection, infection after total knee arthroplasty and chronic osteomyelitis. Postoperative range of motion was checked. The sensibility of flap was evaluated by Semmes-Weinstein monofilaments and two-point discrimination. Results: All flaps survived and provided satisfactory coverage of the defect. There was no complication except one delayed skin graft incorporation at donor site. Seven knee joints which had been stiff previously gained average 58 degrees of ROM postoperatively. All flaps retained sensibility and showed no significant increase in sensory thresholds comparing with contralateral side. Conclusion: Sural artery flap not only shows high survival rate and broad coverage ability, but also offers improvement in range of motion and preservation of sensation. We speculate that sural artery flap is valuable for the reconstruction of the soft tissue defects around knee joint.

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Usefulness of V-Y Advancement Flap for Defects after Skin Tumor Excision

  • Kwon, Ki Hyun;Lee, Dong Gwan;Koo, Su Han;Jo, Myoung Soo;Shin, Heakyeong;Seul, Jung Hyun
    • Archives of Plastic Surgery
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    • v.39 no.6
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    • pp.619-625
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    • 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.

Subunit Principle of Vulvar Reconstruction: Algorithm and Outcomes

  • Tan, Bien-Keem;Kang, Gavin Chun-Wui;Tay, Eng Hseon;Por, Yong Chen
    • Archives of Plastic Surgery
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    • v.41 no.4
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    • pp.379-386
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    • 2014
  • Background Vulvar defects result chiefly from oncologic resection of vulvar tumors. Reconstruction of vulvar defects restores form and function for the purpose of coitus, micturition, and defecation. Many surgical options exist for vulvar reconstruction. The purpose of this article is to present our experience with vulvar reconstruction. Methods From 2007 to 2013, 43 women presented to us with vulvar defects for reconstruction. Their mean age at the time of reconstruction was 61.1 years. The most common cause of vulvar defect was from resection of vulvar carcinoma and extramammary Paget's disease of the vulva. Method s of reconstruction ranged from primary closure to skin grafting to the use of pedicled flaps. Results The main complications were that of long term hypertrophic and/or unaesthetic scarring of the donor site in 4 patients. Twenty-two patients (51%) were able to resume sexual intercourse. There were no complications of flap loss, wound dehiscence, and urethral stenosis. Conclusions We present a subunit algorithmic approach to vulvar reconstruction based on defect location within the vulva, dimension of the defect, and patient age and comorbidity. The gracilis and gluteal fold flaps are particularly versatile and aesthetically suited for reconstruction of a variety of vulvar defects. From an aesthetic viewpoint the gluteal fold flap was superior because of the well-concealed donor scar. We advocate the routine use of these 2 flaps for vulvar reconstruction.

Treatment of Multiple Gingival Recessions Using Vestibular Incision Subperiosteal Tunnel Access with Platelet-rich Fibrin: Two Cases Reports

  • Sung-Min Hwang;Jo-Young Suh
    • Journal of Korean Dental Science
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    • v.16 no.2
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    • pp.218-226
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    • 2023
  • Treatment of multiple gingival recession defects is usually more challenging than that of single gingival recession. Various techniques for the treatment of multiple gingival recession have been established. Recently, vestibular incision subperiosteal tunnel access (VISTA) technique has been considered to exhibit high predictive ability. Connective tissue graft (CTG) has also been considered a gold standard technique owing to its high predictability of root coverage. However, this technique requires a suitable donor site and has clinical disadvantages, such as additional pain. Thus, in this case presentation, platelet-rich fibrin (PRF) was used as an alternative material for CTG along with VISTA. We herein report cases of two patients with Miller's class I and III multiple gingival recession defects, respectively. These patients underwent VISTA along with the use of a PRF membrane. They were followed up for 12 months postoperatively, and their clinical parameters, including probing depth, depth of gingival recession, clinical attachment level, and width of attached gingiva at baseline and at 2, 6, and 12 months postoperatively, were assessed. The patient with class 1 recession defects exhibited a significant amount of root coverage, which remained stable during the follow-up period. Whereas the patient with class 3 recession defects had lesser amount of coverage compared to class 1 patient. The partial coverage observed may be attributed to not only anatomical factors but also the technique-sensitive nature of the procedure. Considering these results, the use of VISTA along with PRF is a viable option for treating gingival recession, as it does not cause discomfort to patients. However, various factors need to be considered during the surgical procedure.

Gametophytic Abortion in Heterozygotes but Not in Homozygotes: Implied Chromosome Rearrangement during T-DNA Insertion at the ASF1 Locus in Arabidopsis

  • Min, Yunsook;Frost, Jennifer M.;Choi, Yeonhee
    • Molecules and Cells
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    • v.43 no.5
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    • pp.448-458
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    • 2020
  • T-DNA insertional mutations in Arabidopsis genes have conferred huge benefits to the research community, greatly facilitating gene function analyses. However, the insertion process can cause chromosomal rearrangements. Here, we show an example of a likely rearrangement following T-DNA insertion in the Anti-Silencing Function 1B (ASF1B) gene locus on Arabidopsis chromosome 5, so that the phenotype was not relevant to the gene of interest, ASF1B. ASF1 is a histone H3/H4 chaperone involved in chromatin remodeling in the sporophyte and during reproduction. Plants that were homozygous for mutant alleles asf1a or asf1b were developmentally normal. However, following self-fertilization of double heterozygotes (ASF1A/asf1a ASF1B/asf1b, hereafter AaBb), defects were visible in both male and female gametes. Half of the AaBb and aaBb ovules displayed arrested embryo sacs with functional megaspore identity. Similarly, half of the AaBb and aaBb pollen grains showed centromere defects, resulting in pollen abortion at the bi-cellular stage of the male gametophyte. However, inheritance of the mutant allele in a given gamete did not solely determine the abortion phenotype. Introducing functional ASF1B failed to rescue the AaBb- and aaBb-mediated abortion, suggesting that heterozygosity in the ASF1B gene causes gametophytic defects, rather than the loss of ASF1. The presence of reproductive defects in heterozygous mutants but not in homozygotes, and the characteristic all-or-nothing pollen viability within tetrads, were both indicative of commonly-observed T-DNA-mediated translocation activity for this allele. Our observations reinforce the importance of complementation tests in assigning gene function using reverse genetics.

Assessment of Defect Risks in Apartment Projects based on the Defect Classification Framework (공동주택 하자분류체계 기반 하자위험 평가)

  • Jang, Ho-Myun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.61-68
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    • 2018
  • In general, defects cause a lot of maintenance costs and serious damage to various stakeholders, such as the owners, contractors or occupants of apartments. For this reason, a systematic and efficient defect management method is needed to minimize defect disputes. This paper derives a defect classification framework and proposes a defect risk assessment model for different types of defects. For this purpose, 6,000 defect items are allocated to the defect classification framework; these items are associated with 34 apartment projects over ten years old. As a result of this analysis, it was confirmed that the defect risks are concentrated in the areas of RC and finishing work. Based on these results, it is necessary to prevent the major risks of defects according to their priority. Based on this research, it is judged that further research to develop a method of managing the risks of defects may be necessary.