• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.216-216
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• 2012

The purpose of this work is to investigate a back surface field (BSF) on variety wafer resistivity for industrial crystalline silicon solar cells. As pointed out in this manuscript, doping a crucible grown Cz Si ingot with Ga offers a sure way of eliminating the light induced degradation (LID) because the LID defect is composed of B and O complex. However, the low segregation coefficient of Ga in Si causes a much wider resistivity variation along the Ga doped Cz Si ingot. Because of the resistivity variation the Cz Si wafer from different locations has different performance as know. In the light of B doped wafer, we made wider resistivity in Si ingot; we investigated the how resistivities work on the solar cells performance as a BSF quality.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.435-437
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• 1998

In this productive system, it needs to control the each axis motion harmoniously to perform accurately for the manufacturing, transporting and printing. Independent Axis Control usually used for this objection. However, if Independent Axis Control mismatched the parameter of each axis system or in the case of free curve tracking or the case of high speed control, there would be big contour error so that cannot achieve control objection. As a result, there is Contour Control method suggested to supply for this defect. This paper carried modeling of biaxial system and implemented Independent Axis Control & Contouring Control on straight line, circular, and coner path by simulation and experiment. If feedrate increased, contour error growed. In consequence, according to this factor, we introduced contouring controller, so we could find the fact that contour error was reduced more than that of independent axis control about each path.

• Journal of International Society for Simulation Surgery
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• v.2 no.2
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• pp.90-93
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• 2015

The fibula free flap has now become the most reliable and frequently used option for mandible reconstruction. Recently, three dimensional images and printing technologies are applied to mandibular reconstruction. We introduce our recent experience of mandibular reconstruction using three dimensionally planned fibula free flap in a patient with gunshot injury. The defect was virtually reconstructed with three-dimensional image. Because bone fragments are dislocated from original position, relocation was necessary. Fragments are virtually relocated to original position using mirror image of unaffected right side of the mandible. A medical rapid prototyping (MRP) model and cutting guide was made with 3D printer. Titanium reconstruction plate was adapted to the MRP model manually. 7 cm-sized fibula bone flap was designed on left lower leg. After dissection, proximal and distal margin of fibula flap was osteotomized by using three dimensional cutting guide. Segmentation was also done as planned. The fibula bone flap was attached to the inner side of the prebent reconstruction plate and fixed with screws. Postoperative evaluation was done by comparison between preoperative planning and surgical outcome. Although dislocated condyle is still not in ideal position, we can see that reconstruction was done as planned.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.1
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• pp.33-39
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• 2022

As 3D printer-related patents expire and major technologies are disclosed, the price of 3D printers is dropping, creating an environment where you can easily find the product you want. In particular, the cheapest FDM (Fused Deposition Modeling) 3D printer is being used in various fields. The FDM method can be manufactured without collapsing of the shape only by attaching a support under certain conditions when outputting the shape. When printing a shape without a support, the irregular surface that occurs at a certain angle is a defect in the product, but it is considered that it can be used as another fun factor in terms of arts and crafts. In this paper, to obtain such an irregular surface, factors that can affect the output were controlled and only the output angle was tested as a displacement factor. As a result of the experiment, it was possible to obtain an irregular surface without the filament flowing down when printing at an angle of 62° to 70° from the vertical. Also, artificially irregular surfaces were applied to craft products.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.5
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• pp.353-357
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• 2020

Fractures of the orbital floor and walls are among the most frequent maxillofacial fractures. Virtual three-dimensional (3D) planning and use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in orbital reconstruction surgery. The presented case was a victim of a terrorist attack involving improvised explosive devices. This 58-year-old female suffered severe wounds caused by a single piece of metal from a bomb, shattering the left orbital floor and lateral orbital wall. Due to remaining hypotropia of the left eye compared to the right eye, late orbital floor reconstruction was carried out with a personalised 3D printed titanium implant. We concluded that this technique with PSI appears to be a viable method to correct complex orbital floor defects. Our research group noted good aesthetic and functional results one year after surgery. Due to the complexity of the surgery for a major bony defect of the orbital floor, it is important that the surgery be executed by experienced surgeons in the field of maxillofacial traumatology.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.28.1-28.4
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• 2020

Background: This clinical case presented a novel method of segmental mandible reconstruction using 3D-printed titanium implant with pre-mounted dental implants that was planned to rehabilitate occlusion. Case presentation: A 53-year-old male who suffered osteoradionecrosis due to the radiation after squamous cell carcinoma resection. The 3D-printed titanium implant with pre-mounted dental implant fixtures was simulated and fabricated with selective laser melting method. The implant was successfully inserted, and the discontinuous mandible defect was rehabilitated without postoperative infection or foreign body reaction during follow-ups, until a year. Conclusions: The 3D-printed titanium implant would be the one of the suitable treatment modalities for mandible reconstruction considering all the aspect of mandibular functions.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.706-713
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• 2021

Objective: To evaluate the impact of surgical simulation training using a three-dimensional (3D)-printed model of tetralogy of Fallot (TOF) on surgical skill development. Materials and Methods: A life-size congenital heart disease model was printed using a Stratasys Object500 Connex2 printer from preoperative electrocardiography-gated CT scans of a 6-month-old patient with TOF with complex pulmonary stenosis. Eleven cardiothoracic surgeons independently evaluated the suitability of four 3D-printed models using composite Tango 27, 40, 50, and 60 in terms of palpation, resistance, extensibility, gap, cut-through ability, and reusability of. Among these, Tango 27 was selected as the final model. Six attendees (two junior cardiothoracic surgery residents, two senior residents, and two clinical fellows) independently performed simulation surgeries three times each. Surgical proficiency was evaluated by an experienced cardiothoracic surgeon on a 1-10 scale for each of the 10 surgical procedures. The times required for each surgical procedure were also measured. Results: In the simulation surgeries, six surgeons required a median of 34.4 (range 32.5-43.5) and 21.4 (17.9-192.7) minutes to apply the ventricular septal defect (VSD) and right ventricular outflow tract (RVOT) patches, respectively, on their first simulation surgery. These times had significantly reduced to 17.3 (16.2-29.5) and 13.6 (10.3-30.0) minutes, respectively, in the third simulation surgery (p = 0.03 and p = 0.01, respectively). The decreases in the median patch appliance time among the six surgeons were 16.2 (range 13.6-17.7) and 8.0 (1.8-170.3) minutes for the VSD and RVOT patches, respectively. Summing the scores for the 10 procedures showed that the attendees scored an average of 28.58 ± 7.89 points on the first simulation surgery and improved their average score to 67.33 ± 15.10 on the third simulation surgery (p = 0.008). Conclusion: Inexperienced cardiothoracic surgeons improved their performance in terms of surgical proficiency and operation time during the experience of three simulation surgeries using a 3D-printed TOF model using Tango 27 composite.

• The Korean Journal of Nuclear Medicine
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• v.3 no.2
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• pp.55-63
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• 1969

In the past few years, scintigraphy has become increasingly important in clinical practice, and the use of a color-printing technique has permited a more accurate interpretation of the scan image. Our liver color scintigrams consist of 51 hepatomas, 35 liver cirrhosis, 22 liver abscessis, 10 hepatitis and other 13 cases of the liver diseases which were clinically arid pathologically diagnosed at Sevarance Hospital, Yonsei Univ., since Feb. 1969 through Sept. 1969. These scintigrams have been analized in terms of various pathologic morphology, such as size, shape, margin of the liver, distribution of radioactivity, and shape of the space occupying lesions. The results are as follows: 1. Enlargement of the liver was the most common finding in the diseased livers. The Rt. lobe enlargement was particularly prominent in the liver abscess. 2. Irregular distribution of radioactivity in the liver (so called mottling) was present in 78% of hepatoma, while it was seen only in 31% of liver abscesses. 3. Liver cirrhosis tends to show perihilar accumulation of the isotope (57%). 4. The deformity of the lower most angle of the Rt. lobe, and the Lt. lateral margin of the Lt. lobe was also impressive throughout the cases ($74{\sim}95%$ of all diseased livers). 5. The frequency of visualization of the spleen was influenced by the size of space occupying lesions and the amount of functioning liver. 6. Differentiation between the liver abscess and hepatoma seems to be possible on scintigram, when shape and margin of defect and patterns of distribution of radioactivity in the remaining liver are clearly demonstrated.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.257-263
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• 2018

The purpose of this study is to develop an automatic inspection system for a part of the differential drive gear into the transmission. This technology will make using the microvision automatic test equipment and automatic test equipment microlaser. This is that the operator intends to make the defect rate 0 in the inspection stage of the product which has been carelessly processed. The equipment developed in this research project will be applied to many areas. Packaging companies, nut bolt processing company, precisely supplier for printing on top of the semiconductor, SMT, etc. The company wants to sell the vision inspection equipment for various applications. If the defective rate of 0 is achieved through this research project, it is also possible to secure a stable supply from the parent company, and to lay the foundations for exporting based on product reliability. When the automatic inspection system is applied to domestic automobile parts processing companies, the reliability of automobiles in Korea will be greatly increased.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.43.1-43.5
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• 2019

Background: Reconstructive surgery is often required for tumors of the oral and maxillofacial region, irrespective of whether they are benign or malignant, the area involved, and the tumor size. Recently, three-dimensional (3D) models are increasingly used in reconstructive surgery. However, these models have rarely been adapted for the fabrication of custom-made reconstruction materials. In this report, we present a case of maxillary reconstruction using a laboratory-engineered, custom-made mesh plate from a 3D model. Case presentation: The patient was a 56-year-old female, who had undergone maxillary resection in 2011 for intraoral squamous cell carcinoma that presented as a swelling of the anterior maxillary gingiva. Five years later, there was no recurrence of the malignant tumor and a maxillary reconstruction was planned. Computed tomography (CT) revealed a large bony defect in the dental-alveolar area of the anterior maxilla. Using the CT data, a 3D model of the maxilla was prepared, and the site of reconstruction determined. A custom-made mesh plate was fabricated using the 3D model (Okada Medical Supply, Tokyo, Japan). We performed the reconstruction using the custom-made titanium mesh plate and the particulate cancellous bone and marrow graft from her iliac bone. We employed the tunneling flap technique without alveolar crest incision, to prevent surgical wound dehiscence, mesh exposure, and alveolar bone loss. Ten months later, three dental implants were inserted in the graft. Before the final crown setting, we performed a gingivoplasty with palate mucosal graft. The patient has expressed total satisfaction with both the functional and esthetic outcomes of the procedure. Conclusion: We have successfully performed a maxillary and dental reconstruction using a custom-made, pre-bent titanium mesh plate.