• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 International Symposium
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• pp.165-172
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• 2003

Wafer-level packaging technology has become established with increase of demands for miniaturizing and realizing lightweight electronic devices evolution. This packaging technology enables the smallest footprint of packaged chip. Various structures and processes has been proposed and manufactured currently, and products taking advantages of wafer-level package come onto the market. The package enables mounting semiconductor chip on print circuit board as is a case with conventional die-level CSP's with BGA solder bumps. Bumping technology is also advancing in both lead-free solder alternative and wafer-level processing such as stencil printing using solder paste. It is known lead-free solder bump formation by stencil printing process tend to form voids in the re-flowed bump. From the result of FEM analysis, it has been found that the strain in solder joints with voids are not always larger than those of without voids. In this paper, characteristics of wafer-level package and effect of void in solder bump on its reliability will be discussed.

• 한국의상디자인학회지
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• 제16권1호
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• pp.53-64
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• 2014

The main objective of this research was to understand the characteristics of printed geometric patterns through the statistical & qualitative analysis of fashion appeared in contemporary female collections 2011 S/S to 2013 A/W. Data collection of 294 was done through review of 'pr$\hat{e}$t-$\grave{a}$-porter Collections' of three major fashion cities; Paris, Milan and NY. Statistical analysis of frequency was conducted. Also qualitative interpretation of natural print design' characteristics were completed. The main findings were as followed; 1,636 of the total 15,852 designs were printed patterns in 12 Collections and the occurrence rate of printed geometric patterns in three collections were 8.6% in Milan, 9.2% in Paris and 12.9% in N.Y. Most geometric patterns were the types of compact or medium density in a front patterns with a variety of sizes and mainly applied to the one piece dress or two piece clothing item combination styles. Formative Characteristics of printed geometric patterns were classified into four types. First, a variety of thicknesses and shapes, such as a line or a rectangle shape to take advantage of the types of the typical geometric pattern. Second types were using the motifs which inspired by geometric shapes such as point, circle star and other special geometric shapes and arranging them regularly with various sizes and density. The third was repeated particular motifs which based on complex and sophisticated mathematical formulas. Fourth were the specific diagram types of bold and free shapes or dividing the flat and arranging them without rules, or the combination type of various geometric motifs.

• 한국의학물리학회지:의학물리
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• 제28권1호
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• pp.33-38
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• 2017

Creating individualized build-up material for superficial photon beam radiation therapy at irregular surface is complex with rice or commonly used flat shape bolus. In this study, we implemented a workflow using 3D printed patient specific bolus and describe our clinical experience. To provide better fitted build-up to irregular surface, the 3D printing technique was used. The PolyLactic Acid (PLA) which processed with nontoxic plant component was used for 3D printer filament material for clinical usage. The 3D printed bolus was designed using virtual bolus structure delineated on patient CT images. Dose distributions were generated from treatment plan for bolus assigned uniform relative electron density and bolus using relative electron density from CT image and compared to evaluate the inhomogeneity effect of bolus material. Pretreatment QA is performed to verify the relative electron density applied to bolus structure by gamma analysis. As an in-vivo dosimetry, Optically Stimulated Luminescent Dosimeters (OSLD) are used to measure the skin dose. The plan comparison result shows that discrepancies between the virtual bolus plan and printed bolus plan are negligible. (0.3% maximum dose difference and 0.2% mean dose difference). The dose distribution is evaluated with gamma method (2%, 2 mm) at the center of GTV and the passing rate was 99.6%. The OSLD measurement shows 0.3% to 2.1% higher than expected dose at patient treatment lesion. In this study, we treated Mycosis fungoides patient with patient specific bolus using 3D printing technique. The accuracy of treatment plan was verified by pretreatment QA and in-vivo dosimetry. The QA results and 4 month follow up result shows the radiation treatment using 3D printing bolus is feasible to treat irregular patient skin.

• 대한화장품학회지
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• 제32권2호
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• pp.123-127
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• 2006

건강하고 병력이 없는 피부를 가진 한국인 여성 중 주름이 생성되기 시작하거나 이미 생성된 30대 33명, 40대 56명, 50대 6명 등 총 95명을 대상으로 눈가에 대한 피부 거칠기와 진피 치밀도 및 피부 두께 측정값간에 상관관계를 확인하였다. 피부거칠기는 Visiometer를 이용하여 5가지 파라미터(Rl, R2, R3, R4, R5)를 분석하였고, 피부 진피 치밀도는 초음파 영상 장치인 Dermascan C를 이용하여 진피 치밀도(intensity)와 피부 두께(distance)를 측정하여 분석하였다. 분석 결과 연령에 따라 피부 거칠기와 진피 치밀도 및 피부 두께간의 깊은 관련성을 확인하였다. 피부 주름 거칠기 파라미터 중에서는 R2 (Maximum roughness)가 피부 두께와 유의한 상관관계가 있었으며(p < 0.05) 또한, 진피 치밀도가 증가함에 따라 피부 두께는 유의하게 감소하는 경향을 보였다(p < 0.05). 따라서 주름 측정 방법에 있어서 기존의 레플리카를 이용한 피부 거칠기 평가 기술과 더불어 진피층의 변화를 측정하는 진피 치밀도 평가 기술은 주름 평가에 매우 유용한 방법이라고 판단된다.

• 펄프종이기술
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• 제30권3호
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• pp.74-83
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• 1998

The phenomenon of decrease in sizing efficiency when the stock temperature is increased is well recognized as summer sizing, and this is believed to be caused by uneven distribution of sizing agents on paper surface most often incurred by coagulation of sizing agents. When unevenly sized paper is used as coating base stock, nonuniform consolidation of the coating layer may result, which, in turn, causes uneven distribution of binder on coating surface. This causes nonuniform ink absorption to produce print mottle. In this study the effects of simple or polymeric electrolytes, storage temperature and time on the coagulation of cationic dispersed rosin size were investigated using a turbidity measurement method which was verified to correlate well with the particle size of rosin emulsion or its coagulates. Handsheets sized with rosin dispersions coagulated under various conditions were prepared and their sizing degree and coated paper properties including gloss and ink density were examined. The relationship between the sizing nonuniformity of coated papers and its ink absorption property was evaluated. Turbidity of rosin emulsion increased as the storage temperature and time were increased. Addition of simple or polymeric electrolytes caused reduction in $zeta$ -potential of the rosin dispersion and accelerated the coagulation tendency substantially. Reversion of the $zeta$ -potential of rosin dispersion, however, did not occur when coagulation was induced with simple electrolytes. On the other hand, addition of an anionic polyelectrolyte reversed the $zeta$ -potential of the flocculated rosin dispersion. This indicated that electrical double layer compaction and bridging flocculation were coagulation mechanisms for simple and polymeric electrolytes, respectively. Sizing degree decreased as coagulation of rosin was increased. Paper gloss, ink gloss and ink density were increased when sizing degree of base stock was increased most probably due to prevention of base paper swelling and increased binder migration to coating surface. This suggested that uneven printing ink density occurred when uneven sizing development was induced by coagulation of rosin particles.

• Fisheries and Aquatic Sciences
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• 제5권1호
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• pp.36-42
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• 2002

Microarrayer is used to make DNA chip and microarray that contain hundreds to thousands of immobilized DNA probes on surface of a microscope slide. This paper shows the develop-ment results for a printing type of microarrayer. It realizes a typical, low-cost and efficient microarrayer for generating low density micro array. The microarrayer is developed by using a prependicular type robot with three axes. It is composed of a computer-controlled three-axes robot and a pen tip assembly. The key component of the arrayer is the print-head containing the tips to immobilize cDNA, genomic DNA or similar biological material on glass surface. The robot is designed to automatically collect probes from two 96-well plates with up to 12 pens at the same time. To prove the performance of the developed microarrayer, we use the general water types of inks such as black, blue and red. The inks are distributed at proper positions of 96 well plates and the three color inks are immobilized on the slide glass under the operation procedure. As the result of the test, we can see that it has sufficient performance for the production of low integrated DNA chip consisted of 96 spots within $1cm^2$ area.

• 한국항행학회논문지
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• 제12권5호
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• pp.483-493
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• 2008

IEEE 802.11 WLAN 표준에 근거한 수신 신호세기 측정치에 기반하여 무선 측위를 수행함에 있어서 이기종 이동기기 수신 감도 문제는 이동기기의 종류가 다양해짐에 따라 중요한 문제로 인식되고 있다. 본 논문에서는 이기종 이동기기 수신 감도 문제를 효과적으로 극복할 수 있는 Hybrid Kriging 알고리즘을 제안하고 시뮬레이션과 실험을 통하여 그 성능을 분석하였다. 시뮬레이션과 실험 결과에 의하면 동일한 기준 측정치가 주어진 경우 제안된 Hybrid Kriging 알고리즘이 현제 널리 활용되고 있는 위치 지문 알고리즘에 비하여 이동기기 수신 신호세기 바이어스가 존재하는 경우에도 보다 더 정확한 위치해를 생성할 수 있음을 알 수 있었다.

• 한국인쇄학회지
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• 제20권1호
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• pp.133-145
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• 2002

전자사진은 디지털 기술의 급속한 발전에 의하여 그 응용 범위가 확대되고있으나, 은염사진과 원리와 특성이 근본적으로 다르며 은염사진에 익숙한 사용자에게도 은염사진과 유사한 특성을 보이도록 화상의 개선과 화질의 보정 등이 요구된다. 본 논문은 은염사진의 계조 특성을 추출하여 전자화상시스템에 적용시켜 은염사진의 계조 특성을 지닌 전자화상을 출력하는 방법을 제시한다. 먼저, 은염사진과 전자사진의 화상 생성 공정을 구체적으로 비교하여 그 차이를 기술하고, 사진 계조 변환의 원리와 방법을 제시한다. 다음으로 사진 계조 변환함수를 구하기 위한 각 시스템의 특성화의 실험을 수행한 결과를 보인다. 최종적으로 이론을 바탕으로 한 실험에서는 사진 계조로 변환된 데이터를 디지털 화상시스템으로 출력하여 은염사진의 계조 특성의 비교분석을 수행한다.

• 펄프종이기술
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• 제44권2호
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• pp.42-48
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• 2012

In the 21st century, the printing industry as well as the IT industry has made rapid development. However, despite these technological advancement in the printing industry, it is still harmful for the environment, the state regulation is insufficient. Therefore, we studied the printability for the existing heat-set web inks and the newly created phenol-free eco-inks. This ink was made by reacting rosin and unsaturated dibasic acid and ester reactant, ester reactant was used instead of phenol. Printability test were used in the IGT printability tester. Experimental conditions, the temperature $22.7^{\circ}C$, humidity 57% under conditions of 0.6cc of ink supply, the print speed 1m/sec, pressures were set at 250N. As results of this study, we were able to get the following conclusions. The properties of phenol-free ink is the same as the existing inks. So we are thought to improve some characteristics such as dispersion, able to replace the existing ink.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.899-904
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• 2003

Microarrayer makes DNA chip and microarray that contain hundreds to thousands of immobilized DNA probes on surface of a microscope slide. This paper shows the development results for a printing type of microarrayer. It realizes a typical, low-cost and efficient microarrayer for generating low density microarray. The microarrayer is developed by using a robot of three-axes perpendicular type. It is composed of a computer-controlled three-axes robot and a pen tip assembly. The key component of the arrayer is the print-head containing the tips to immobilize cDNA, genomic DNA or similar biological material on glass surface. The robot is designed to automatically collect probes from two 96-well plates with up to 32 tips at the same time. To prove the performance of the developed microarrayer, the general water types of inks such as black, blue and red. The inks are distributed at proper positions of 96 well plates and the three color inks are immobilized on the slide glass under the operation procedure. As the result of the test, it can be shown that it has sufficient performance for the production of low integrated DNA chip consisted of 96 spots within 1 $cm^2$ area.