• 전자통신동향분석
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• 제37권4호
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• pp.28-35
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• 2022

To solve the challenge of waste plastics, this study investigated the related technologies and company trends along the plastic life cycle, and primarily describes ICT technologies to improve efficiency in the process of sorting and sorting waste plastics. Waste plastic discharge caused by the explosive increase in parcel traffic because of COVID-19 is also growing exponentially. Hence, waste treatment is emerging as a social challenge. Most of the domestic waste classification depends on the manual process according to the waste pollution level. The plastic material classification approach using the spectroscopy approach reveals a high error in the contaminated waste plastic classification, but if the Artificial Intelligence-based image classification technology is employed together, the classification precision can be enhanced because of the type of waste plastic product and the contaminated part can be differentiated.

• International Journal of Computer Science & Network Security
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• 제24권6호
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• pp.89-98
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• 2024

Due to the increase in population and consequently the increase in the production of plastic waste, recovery of this part of the waste is an undeniable necessity. On the other hand, the recycling of plastic waste, if it is placed in a systematic process and controlled, can be effective in creating jobs and maintaining environmental health. Waste collection in many large cities has become a major problem due to lack of proper planning with increasing waste from population accumulation and changing consumption patterns. Today, waste management is no longer limited to waste collection, but waste collection is one of the important areas of its management, i.e. training, segregation, collection, recycling and processing. In this study, a systematic method based on machine vision for sorting plastic bottles in different colors for recycling purposes will be proposed. In this method, image classification and segmentation techniques were presented to improve the performance of plastic bottle classification. Evaluation of the proposed method and comparison with previous works showed the proper performance of this method.

• 한국정밀공학회지
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• 제19권6호
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• pp.29-34
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• 2002

This paper presents formation of ejector-pin hollowness in injection molding. Injection molding process is widely used in production of plastic part for good dimensional accuracy and high productivity. However, the injection molding leaves ejector-pin hollowness on pal, which causes bad part surface and quality. Dimensions and profiles of ejector-pin hollowness are measured for formation or ejector-pin hollowness. The formation of ejector-pin hollowness is traced with dimensions and profiles of ejector-pin hollowness. The compression force and moment cause ejector-pin to form hollowness on part surface.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1772-1777
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• 2007

This paper provides plastic limit loads of pipes with constant-depth, circumferential part-through surface cracks under combined pressure and bending. A key issue is to postulate discontinuous hoop stress distributions in the net-section. Validity of the proposed limit load solutions is checked against the results from three-dimensional (3-D) finite element (FE) limit analyses using elastic-perfectly plastic material behavior.

• 한국분말재료학회지
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• 제3권2호
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• pp.104-111
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• 1996

In order to obtain homogeneous and high quality products in powder compaction forging process, it is very important to control stress, strain, density and density distributions. Therefore, it is necessary to understand quantitatively the elasto-plastic deformation and densification behaviors of porous metals and metal powders. In this study, elasto-plastic finite element method using Lee-Kim's pressure dependent porous material yield function has been used for the analysis of three dimensional indenting process. The analysis predicts deformed geometry, stress, strain and density distribution and load. The calculated load is in good agreement with experimental one. The calculated results do not show axisymmetric distributions because of the edge effect. The core part which is in contact with the indentor and the outer diagonal edge part are in compressive stress states and the middle part is in tensile stress state. As a results, it can be concluded that three dimensional analysis is more realistic than axisymmetric assumption approach.

• Archives of Reconstructive Microsurgery
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• 제10권1호
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• pp.44-48
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• 2001

The pedicled fillet flap concept has been successfully applied in both the upper and lower extremities for the treatment of difficult wounds. However, in case of complete extremity amputation in eletrical burn patient, the transfer of pedicled flaps from the amputated part is not possible. In such instances, we have designed total arm musculocutaneous free-fillet flaps from the amputated limb to provide wound coverage, when replantation of the amputated part was contraindicated. now we present such a case. This technique allows immediate wound coverage without the morbidity of an additional donor site. The flap provides the ideal combination of large surface area, muscle bulk, and long vascular pedicle. It can be dissected rapidly to minimize ischemic time and could therefore be applicable to traumatic forequarter amputations.

• 한국실내디자인학회논문집
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• 제29호
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• pp.35-42
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• 2001

As a part of Avant-Garde movement centered in Russia before and after the Revolution in 1917, Russian Constructivism was born as most experimental and avant-garde modernity artistic movement. Russian Constructivism played a significant part in relative to Avant-Garde in the beginning of twentieth century and has contributed to a series of artistic movement, it deserves a status befitting its contribution to modem abstract art. Noticing the fact that Constructivist approaches are being attempted in modern architecture with the new rise of Constructivist design theory and increased interest in Constructivism, this thesis explores the design elements characterizing Constructivism in art and architecture To be specific, it suggests the relation of Plastic paradigm in formalistic, elemental and technical aspects and categories into Plastic characteristics. Thereby, the thesis aims to categorize the elements in terms of contradicting two trends of pure plastic and scientific expressions, and to analyze comparatively the related Plastic trends represented in modern space design. The thesis recolonizes that attempts to break out from stereotypes of Constructivism to reinvent itself constantly have contributed to an unconventional forms and new aesthetic standards and have a great impact on idealistic forms in many genres.

• Archives of Plastic Surgery
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• 제38권6호
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• pp.883-885
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• 2011

Purpose: Nevus sebaceus is a congenital hamartomatous lesion, typically involving head and neck. Various benign and malignant neoplasms can develop in association with nevus sebaceus. We report a case of simultaneous occurrence of squamous cell carcinoma and basal cell carcinoma in nevus sebaceus. Methods: A 73-year-old man presented with erythematous to black verrucous nodules on the right subauricular area. The upper part was accompanied with inflammation and ulceration, and no specific findings suspicious for malignant degeneration were found in the lower part preoperatively. The mass was totally excised and the defect was directly closed. Lymph nodes were not involved on concomitant neck dissection. Results: Histopathologic examination confirmed the presence of squamous cell carcinoma in the upper part and basal cell carcinoma in the lower part of a nevus sebaceus. Negative margins were achieved on resection. No clinical problems were found during the 3-month follow-up period. Conclusion: We experienced a rare case of simultaneous occurrence of squamous cell carcinoma and basal cell carcinoma within the same nevus sebaceus. Because patients with nevus sebaceus have risk of malignant changes, surgical excision and work-up for recurrence and metastasis should be considered in suspicious cases. And even in a totally asymptomatic case, the possibility of occult secondary cancer should be informed before surgery in aged patients.

• Archives of Plastic Surgery
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• 제50권1호
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• pp.130-140
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• 2023

Microsurgery, which deservedly sits on top of the reconstruction ladder, has been a boon to plastic surgery. It is because of this marvelous tool that plastic surgeons the world over have been able to tackle many reconstructive dilemmas, which were once considered to be an improbability. Microsurgery-aided revolutions have rendered a new meaning to all forms of reconstruction-whether it is postoncological, posttraumatic, or postlymphedema reconstruction. As the most advanced reconstructive medium at our disposal that has broadened the horizons of plastic surgery exponentially, it is but obvious that many budding plastic surgeons are drawn toward this subspecialty. In lieu of the aforementioned facts, it is necessary to sensitize all such aspiring surgeons about the various intricacies concerning the field of microsurgery. This article with its focus on the six desirable microsurgical attributes of "Clarity, Curiosity, Perseverance, Passion, An Open Mindset and Action," is meant to be a modest attempt on part of the authors to share their microsurgical insights, procured through their respective journeys, with budding aspirants, hoping to sensitize as well as motivate them for the challenging path that lies ahead.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.309-312
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• 2010

Purpose: An osteoma is one of the common benign tumors that penetrate the nasal portion, paranasal and frontal sinus. This tumor is mostly found by radiation test accidentally, however in rare cases; it can be found to be touched or with its symptoms as the tumor grows. We report this case since we found and healed the benign tumor which was affecting orbit and the both sides of fronal sinus. Methods: A 19 year old female patient visited to our hospital due to the mass on her forehead. The symptoms began 3 years ago but no special symptom was found except for touchable mass. She was diagnosed as the osteoma of superior orbital parts and both sides of frontal sinus using X-ray and CT scanning. The size of osteoma was $5{\times}2.5{\times}3.5\;cm$ and indicated the patterns penetrated to the right side of orbital region. The osteoma excision was conducted with coronal incision and wide area of defect part in frontal sinus and superior orbital part were reconstructed by cranial bone graft and resorbable fixation plates. Results: The patient recovered without any postoperative infections or complications and symptoms. Dysaesthesia was found on her frontal area but improved in 1 month after the surgery. Conclusion: The occurrences of osteoma in frontal sinus are rare and can be treated with conservative methods if there are no infections and symptoms. We report this case since we found the benign tumor, which was affecting orbit and the both sides of fronal sinus and healed it with coronal resectomy without any complications.