• Title/Summary/Keyword: 3-dimensional manufacturing process

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Stacked Pad Area Away Package Modules for a Radio Frequency Transceiver Circuit (RF 송수신 회로의 적층형 PAA 패키지 모듈)

  • Jee, Yong;Nam, Sang-Woo;Hong, Seok-Yong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.10
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    • pp.687-698
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    • 2001
  • This paper presents a three dimensional stacked pad area away (PAA) package configuration as an implementation method of radio frequency (RF) circuits. 224MHz RF circuits of intelligence traffic system(ITS) were constructed with the stacked PAA RF pakage configuration. In the process of manufacturing the stacked PAA RF pakage, RF circuits were partitioned to subareas following their function and operating frequency. Each area of circuits separated to each subunits. The operating characteristics of RF PAA package module and the electrical properties of each subunits were examined. The measurement of electrical parameters for solder balls which were interconnects for stacked PAA RF packages showed that the parasitic capacitance and inductance were 30fF and 120pH, respectively, which might be negligible in PAA RF packaging system. HP 4396B network/spectrum analyzer revealed that the amplification gain of a receiver and transmitter at 224 MHz was 22dB and 27dB, respectively. The gain was 3dB lower than designed values. The difference was probably generated from fabrication process of the circuits by employing commercial standard

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Comparative Study on Mechanical Properties and Dimensional Stability of Staypak and Wood-Polymer Composites from Populus alba × P. Glandulosa wood (현사시나무로 제조(製造)된 열압축목재(熱壓縮木材)와 목재(木材)-고분자(高分子) 복합체(複合體) 재질(材質)의 비교연구(比較硏究))

  • Pak, Sang-Bum;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.13 no.2
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    • pp.14-34
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    • 1985
  • One of the techniques for altering the properties of wood that has received considerable attention in the last twenty years is the formation of a wood-polymer composite (WPC) by irradiation and heat-catalyst polymerization of a monomer incorporated into the wood matrix. Wood-polymer composites are the new products having the superior mechanical and physical properties and the combinated characteristics of wood and plastic. The purpose of this experiment was to obtain the basic data for the improvement of wooden materials by manufacturing WPC and Staypak. The species examined was Hyunsasi-Namoo (Populus alba ${\times}$ P. glandulosa) which had not been utilized yet. Methylmethacrylate (MMA) as monomer, benzoyl peroxide (BPO) as initiator and methyl alcohol as bulking agent were used. The monomer containing BPO was impregnated into wood pieces by the dipping and the vacuum process for 2 hours. After impregnation, the treated samples were polymerized on the hot press with pressure and heat-catalyst methods. The results obtained were summarized as follows 1. The monomer loading into wood by the dipping process was 12.13 percent and 29.99 percent by the vacuum. The polymer loading into wood by the dipping process was 6.79 percent and 15.44 percent by the vacuum. 2. Comparing with Staypak, antishrink efficiency (ASE) of WPC was 12.5 to 13.6 percent on the radial direction and 14.70 to 18.63 percent on the tangential. Antiswelling efficiency (AE) was 14.40 to 17.22 percent on the radial direction and 17.18 to 42.1 8 to 42.14 percent on the tangential. Reduction in water absorptivity (RWA) was 8.19 to 15.5 percent. As a whole, the vacuum process was better than the dipping. 3. The specific gravity of control, Staypak and WPC were 0.44, 0.66 and 0.61 to 0.62, respectively. 4. In the bending strength test, the strength in case that the load direction is on the radial surface was greater than that which the load direction is on the tangential. 5. Increasing rate of stress at proportional limit in compression perpendicular to grain was 72.26 percent in case of WPC by the dipping process, 78.93 percent by the vacuum and 99.09 percent in case of Staypak.

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Study on an Electrostatic Deflector for Ultra-miniaturized Microcolumn to Realize sub-10 nm Ultra-High Resolution and Wide Field of View (10 nm 이하 초고해상도와 광폭 관측시야를 구현하기 위한 극초소형 마이크로컬럼용 정전형 디플렉터 연구)

  • Lee, Hyung Woo;Lee, Young Bok;Oh, Tae-Sik
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.4
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    • pp.29-37
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    • 2021
  • A 7 nm technology node using extreme ultraviolet lithography with a wavelength of 13.5 nm has been recently developed and applied to the semiconductor manufacturing process. Furthermore, the development of sub-3 nm technology nodes continues to be required. In this study, design factors of an electrostatic deflector for an ultra-miniaturized microcolumn system that can realize an electron wavelength of below 1.23 nm with an acceleration voltage of above 1 eV were investigated using a three-dimensional simulator. Particularly, the optimal design of the electrostatic octupole floating deflector was derived by optimizing the design elements and improving the driving method of the 1 keV low energy ultra-miniaturized microcolumn deflector. As a result, the entire wide field of view greater than 330 ㎛ at a working distance of 4 mm was realized with an ultra-high-resolution electron beam spot smaller than 10 nm. The results of this study are expected to be a basis technology for realizing a wafer-scale multi-array microcolumn system, which is expected to innovatively improve the throughput per unit time, which is the biggest drawback of electron beam lithography.

Colloidal Optics and Photonics: Photonic Crystals, Plasmonics, and Metamaterials

  • Jaewon Lee;Seungwoo Lee
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.608-637
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    • 2023
  • The initial motivation in colloid science and engineering was driven by the fact that colloids can serve as excellent models to study atomic and molecular behavior at the mesoscale or microscale. The thermal behaviors of actual atoms and molecules are similar to those of colloids at the mesoscale or microscale, with the primary distinction being the slower dynamics of the latter. While atoms and molecules are challenging to observe directly in situ, colloidal motions can be easily monitored in situ using simple and versatile optical microscopic imaging. This foundational approach in colloid research persisted until the 1980s, and began to be extensively implemented in optics and photonics research in the 1990s. This shift in research direction was brought by an interplay of several factors. In 1987, Yablonovitch and John modernized the concept of photonic crystals (initially conceptualized by Lord Rayleigh in 1887). Around this time, mesoscale dielectric colloids, which were predominantly in a suspended state, began to be self-assembled into three-dimensional (3D) crystals. For photonic crystals operating at optical frequencies (visible to near-infrared), mesoscale crystal units are needed. At that time, no manufacturing process could achieve this, except through colloidal self-assembly. This convergence of the thirst for advances in optics and photonics and the interest in the expanding field of colloids led to a significant shift in the research paradigm of colloids. Initially limited to polymers and ceramics, colloidal elements subsequently expanded to include semiconductors, metals, and DNA after the year 2000. As a result, the application of colloids extended beyond dielectric-based photonic crystals to encompass plasmonics, metamaterials, and metasurfaces, shaping the present field of colloidal optics and photonics. In this review we aim to introduce the research trajectory of colloidal optics and photonics over the past three decades; To elucidate the utility of colloids in photonic crystals, plasmonics, and metamaterials; And to present the challenges that must be overcome and potential research prospects for the future.

Image Processing Technology for Analyzing the Heating State of Carbon Fiber Surface Heating Element (탄소섬유 면상발열체의 발열 상태 분석을 위한 영상처리 기술)

  • Cho, Joon-Ho;Hwang, Hyung-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.683-688
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    • 2018
  • In this study, we analyzed the heat generation state of a flat heating element by using image processing technology in conjunction with carbon fiber. The flat heating element is manufactured by chopping the carbon fiber to a small size and bonding it again using a dispersing agent. The solution of carbon fiber, bound together using the dispersant, is then filtered onto the nonwoven fabric. The last step is to obtain flat carbon fibers in the form of nonwoven fabrics for the purpose of drying the filtered carbon fibers. In the flat heating element, electricity may be applied to the carbon fiber on the surface produced in this manner. In this study, the flat heating element was analyzed by four methods. The analysis of the heat generation characteristics and heating rate of the flat heating element confirmed that the fabricated sheet heating element corresponds to a normal army. The analysis of the insulation coating and flat heating element module, which can be used for actual product manufacturing, involves two dimensional image analysis using image processing technology. The thermal image analysis of the flat heating element is a programming technique that not only analyzes the heat generation state in both two and three dimensions, but also displays the upper and lower 15 to 20% ranges of temperature corresponding to the heat generation in the image. In the final analysis, it is possible to easily find the erroneous part in the manufacturing process by directly showing the state of the fabricated flat heating element on the screen. By combining this image analysis method of the flat heating element with the existing method, we were able to more accurately analyze the heat generation state.

Examination of Aggregate Quality Using Image Processing Based on Deep-Learning (딥러닝 기반 영상처리를 이용한 골재 품질 검사)

  • Kim, Seong Kyu;Choi, Woo Bin;Lee, Jong Se;Lee, Won Gok;Choi, Gun Oh;Bae, You Suk
    • KIPS Transactions on Software and Data Engineering
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    • v.11 no.6
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    • pp.255-266
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    • 2022
  • The quality control of coarse aggregate among aggregates, which are the main ingredients of concrete, is currently carried out by SPC(Statistical Process Control) method through sampling. We construct a smart factory for manufacturing innovation by changing the quality control of coarse aggregates to inspect the coarse aggregates based on this image by acquired images through the camera instead of the current sieve analysis. First, obtained images were preprocessed, and HED(Hollistically-nested Edge Detection) which is the filter learned by deep learning segment each object. After analyzing each aggregate by image processing the segmentation result, fineness modulus and the aggregate shape rate are determined by analyzing result. The quality of aggregate obtained through the video was examined by calculate fineness modulus and aggregate shape rate and the accuracy of the algorithm was more than 90% accurate compared to that of aggregates through the sieve analysis. Furthermore, the aggregate shape rate could not be examined by conventional methods, but the content of this paper also allowed the measurement of the aggregate shape rate. For the aggregate shape rate, it was verified with the length of models, which showed a difference of ±4.5%. In the case of measuring the length of the aggregate, the algorithm result and actual length of the aggregate showed a ±6% difference. Analyzing the actual three-dimensional data in a two-dimensional video made a difference from the actual data, which requires further research.

Evaluation of incremental sheet forming characteristics for 3D-structured aluminum sheet - part 2 (3D 구조 알루미늄 판재의 점진판재성형 특성 평가 (제2보))

  • Kim, Young-Suk;Do, Van-Cuong;Ahn, Dae-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1585-1593
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    • 2015
  • 3D-structured (embossed) aluminum sheets have been used in the heat insulation purpose for automative exhaust parts because of increasing their surface areas and stiffness reinforcement imposed in making the embossing pattern. However, there are many restrictions in press forming of the embossed sheet compared with the flat sheet (non-embossed one) because of its difference in the mechanical properties and the geometrical 3-dimensional shape. In this paper we investigated the deformation characteristic of embossed aluminum sheet in the incremental sheet forming process which has frequently used in the design verification and the trial manufacturing of sheet products. The single point incremental forming (SPIF) experiments for the rectangular cone forming using the CNC machine with a chemical wood-machined die and a circular tool shape showed that the formability of the embossed sheet are better than that of the flat sheet in view of the maximum angle of cone forming. This comes from the fact that the embossed sheet between the tool and the elastic die wall is plastically compressed and the flatted area contributes to increase the plastic deformation. Also the tool path along the outward movement from the center showed a better formability than that of the inward movement from the edge. However the surface quality for the tool path along the outward movement evaluated from the surface deflection is inferior than that of the tool path along the inward movement.

Process Development of a Virally-Safe Acellular Bovine Amniotic Membrane for Biological Dressing (바이러스 안전성이 보증된 무세포 소 양막 생물창상피복재 제조 공정 개발)

  • Bae, Jung-Eun;Kim, Chang-Kyong;Kim, Sung-Po;Yang, Eun-Kyung;Kim, In-Seop
    • Microbiology and Biotechnology Letters
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    • v.38 no.4
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    • pp.420-427
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    • 2010
  • A process for manufacturing virally-safe bovine amniotic membrane(BAM) has been developed for biological dressing. BAM was harvested from a healthy bovine placenta, and then the epithelium was removed. The remaining stromal layer was consecutively disinfected with 70% ethanol and 0.05% sodium hypochlorite. The stromal layer was incubated in a decellularization solution containing 0.25%(w/v) trypsin to remove the cellular components. The resulting acelluar BAM was lyophilized to preserve its biochemical and structural integrity. The BAM was packed and exposed to 25 kGy of gamma irradiation for sterilization purpose. Histological, electron microscopical, and biochemical observations showed that the acellualr BAM had intact structural integrity of three dimensional collagen fibers and contained several growth factors, accelerating wound healing, such as EGF (Epidermal growth factor), KGF (Keratinocyte growth factor), and FGF (Fibroblast growth factor). Bovine herpes virus (BHV), bovine viral diarrhoea virus (BVDV), bovine parainfluenza virus type 3 (BPIV-3), and bovine parvovirus (BPV) were chosen as the biological indicators for validation of viral safety of the acellular BAM. Samples from relevant stages of the production process were spiked with each virus and subjected to viral inactivation processes. Viruses were recovered from the samples and then titrated immediately. All the viruses tested were completely inactivated to undetectable levels within 1 h of 70% ethanol treatment. Enveloped viruses such as BHV, BVDV, and BPIV-3 were more effectively inactivated than BPV by 0.05% sodium hypochlorite treatment. BHV, BVDV, and BPIV-3 were completely inactivated to undetectable levels by 25 kGy of gamma irradiation. Also BPV was effectively inactivated by 25 kGy of gamma irradiation. The cumulative log reduction factors of BHV, BVDV, BPIV-3, and BPV were ${\geq}$13.30, ${\geq}$14.32, ${\geq}$15.22, and ${\geq}$7.57, respectively. These results indicate that the production process for acelluar BAM has a sufficient virus-reducing capacity to achieve a high margin of the virus safety.

Study on 3D Printer Suitable for Character Merchandise Production Training (캐릭터 상품 제작 교육에 적합한 3D프린터 연구)

  • Kwon, Dong-Hyun
    • Cartoon and Animation Studies
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    • s.41
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    • pp.455-486
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    • 2015
  • The 3D printing technology, which started from the patent registration in 1986, was a technology that did not attract attention other than from some companies, due to the lack of awareness at the time. However, today, as expiring patents are appearing after the passage of 20 years, the price of 3D printers have decreased to the level of allowing purchase by individuals and the technology is attracting attention from industries, in addition to the general public, such as by naturally accepting 3D and to share 3D data, based on the generalization of online information exchange and improvement of computer performance. The production capability of 3D printers, which is based on digital data enabling digital transmission and revision and supplementation or production manufacturing not requiring molding, may provide a groundbreaking change to the process of manufacturing, and may attain the same effect in the character merchandise sector. Using a 3D printer is becoming a necessity in various figure merchandise productions which are in the forefront of the kidult culture that is recently gaining attention, and when predicting the demand by the industrial sites related to such character merchandise and when considering the more inexpensive price due to the expiration of patents and sharing of technology, expanding opportunities and sectors of employment and cultivating manpower that are able to engage in further creative work seems as a must, by introducing education courses cultivating manpower that can utilize 3D printers at the education field. However, there are limits in the information that can be obtained when seeking to introduce 3D printers in school education. Because the press or information media only mentions general information, such as the growth of the industrial size or prosperous future value of 3D printers, the research level of the academic world also remains at the level of organizing contents in an introductory level, such as by analyzing data on industrial size, analyzing the applicable scope in the industry, or introducing the printing technology. Such lack of information gives rise to problems at the education site. There would be no choice but to incur temporal and opportunity expenses, since the technology would only be able to be used after going through trials and errors, by first introducing the technology without examining the actual information, such as through comparing the strengths and weaknesses. In particular, if an expensive equipment introduced does not suit the features of school education, the loss costs would be significant. This research targeted general users without a technology-related basis, instead of specialists. By comparing the strengths and weaknesses and analyzing the problems and matters requiring notice upon use, pursuant to the representative technologies, instead of merely introducing the 3D printer technology as had been done previously, this research sought to explain the types of features that a 3D printer should have, in particular, when required in education relating to the development of figure merchandise as an optional cultural contents at cartoon-related departments, and sought to provide information that can be of practical help when seeking to provide education using 3D printers in the future. In the main body, the technologies were explained by making a classification based on a new perspective, such as the buttress method, types of materials, two-dimensional printing method, and three-dimensional printing method. The reason for selecting such different classification method was to easily allow mutual comparison of the practical problems upon use. In conclusion, the most suitable 3D printer was selected as the printer in the FDM method, which is comparatively cheap and requires low repair and maintenance cost and low materials expenses, although rather insufficient in the quality of outputs, and a recommendation was made, in addition, to select an entity that is supportive in providing technical support.

Full mouth rehabilitation with fixed implant-supported prosthesis using temporary denture and double digital scanning technique: a case report (임시 의치와 이중 디지털 스캐닝 기법을 활용한 전악 고정성 임플란트 수복 증례)

  • Seok-Hyun Shin;Chan-Ik Park;Se-Ha Kang;Ji-Eun Moon;Min-Seok Oh;Chul-Min Park;Woo-Jin Jeon;Seong-Gu Han;Sun-Jae Kim;Su-Jin Choi
    • The Journal of Korean Academy of Prosthodontics
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    • v.61 no.3
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    • pp.245-256
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    • 2023
  • When restoring with a dental digital system for implant-supported prosthesis, a double digital scanning technique is required: an intraoral scan of the three-dimensional implant location and intraoral scan after placement of temporary denture or provisional prosthesis. During the intraoral scan, the use of scan body as a stable landmark can improve the accuracy of digital impression and simplify laboratory process. In this case, a full-digital system was used to plan and fabricate a custom abutment, provisional prosthesis, and definitive prosthesis. After implant placement, the scan area of the intraoral scan body connected with implant and the intraoral scan body marked on the inside of temporary denture were superimposed. Out of the superimposed files, a custom abutment and provisional prosthesis were fabricated which match the vertical dimension of temporary denture, and definitive prosthesis was fabricated based on provisional prosthesis. We report this case because result has been functionally and esthetically satisfactory by using vertical dimension and central relation set during the fabrication of temporary denture to the definitive prosthesis.