• Title, Summary, Keyword: FFS

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A study on Electro-Optical Characteristics of the UV Aligned FFS Cell on the Organic Layer (유기막에 UV 배향한 FFS 액정셀의 전기광학특성)

  • Han, Jeong-Min;Hwang, Jeoung-Yeon;Kim, Byoung-Yong;Han, Jin-Woo;Kim, Jong-Hwan;Lee, Sang-Keuk;Oh, Yong-Cheul;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.278-279
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    • 2006
  • In this study, we investigated the electro-optical (EO) characteristic of fringe-field switching (FFS) mode cell by the two kinds of ultraviolet (UV) alignment method on the organic thin film (polyimide Pl). The suitable organic layers for FFS cell and the aligning capabilities of nematic liquid crystal (NLC) using the in-situ photo-alignment method were studied. An unstable V-T curve of UV-aligned FFS-LCD with conventional photo-alignment method can be achieved. However, a stable V-T curve of UV-aligned FFS-LCD with in-situ photo-alignment method (1h), and V-T curve of UV-aligned FFS-LCD with in-situ photo-alignment method was much stable comparing with that of other UV-aligned FFS-LCD's, As a result, more stable EO performance of UV-aligned FFS-LCD with in-Situ photo-alignment method is obtained than that of the other UV-aligned FFS-LCD's.

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IPS(In-Plane Switching) / FFS(Fringe-Field Switching) 기술 진화 소개 및 최근 개발 현황

  • Lee, Seung-Hui
    • Information Display
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    • v.14 no.1
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    • pp.30-37
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    • 2013
  • 지난 20년 동안 TFT-LCD의 화질은 급격하게 발전해 왔다. 특히 IPS와 VA의 기술경쟁을 통해 서로의 단점을 극복하려는 많은 연구가 수행돼왔다. 하지만 이제는 발광디스플레이의 출현으로 이제는 액정기술 간의 경쟁은 의미 없고 TFT-LCD의 화질/기능/비용면에서 발광디스플레이보다 우수해야 하는 당면 과제를 안고 있다. 현재 IPS기술은 FFS기술을 통해 한층 더 발전하였고 이제는 고화질 제품엔 FFS 채용이 기본화되고 있다. FFS 기술개발에 초기부터 참여하고 지금까지 FFS기술을 연구하고 있는 필자의 관점에서 보면 FFS는 1998년 발표이후 매 6년 마다 중대한 변화가 있었고 그 예가 2004년 히타치사 TV패널에 FFS기술 적용, 2010년 애플사 아이패드에 FFS 기술 채용이다. 현재 기술 흐름으로 볼 때 2016년 정도엔 FFS기술 + 산화물 반도체 + 광배향 기술을 적용한 FFS TV가 시장의 한 축이 되길 필자는 기대해본다. 마지막으로 필자의 경험을 바탕으로 평가한 각 기술들에 대해 다른 전문가들과 이견이 있을 수 있음을 인정하니 많은 양해 부탁드립니다.

Perception and Satisfaction of Free Foodservice in Male Middle School Students in Chungnam (충남 일부지역 남자 중학생의 무상급식에 대한 인식 및 만족도)

  • Kim, Yu-Rin;Kim, Eun-Jin;Choi, Mi-Kyeong
    • Journal of the Korean Dietetic Association
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    • v.20 no.2
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    • pp.87-98
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    • 2014
  • The purpose of this research was to investigate perception, necessity, and satisfaction of a free foodservice in male middle school students. This study was conducted at male middle schools with paid foodservice (PFS group, 250 students) and with free foodservice (FFS group, 250 students) in Chungnam. Average age of students in the PFS group was 13.1 while that of FFS students was 12.8 years. Exactly 88% of PFS students and 94% of FFS students responded that school foodservice is necessary, which was a significant difference (P<0.05). As the reason for participating in foodservice, about 32% of the PFS students answered the school's request while 33.6% of FFS students answered nutrition, showing a significant difference (P<0.001). Exactly 72.8% of PFS and 96.4% of FFS knew about FFS (P<0.001). More PFS students (86.4%) than FFS students (66%) answered they would not participate in foodservice if the FFS would be introduced and the quality of meal service would deteriorate. After initiation to FFS, there were significant differences in assessment of foodservice: 77.6% of PFS students answered expected that the quality of foodservice would degrade, whereas 74.4% of FFS students answered that quality would not degrade (P<0.001). Satisfaction of foodservice was 2.3 points for FFS students, which was significantly lower than the 2.5 points for PFS students (P<0.001). To sum up assessment of foodservice was positive, whereas satisfaction was not significantly different between PFS and FFS. Based on this research, households, schools, and governments should promote FFS in order to diminish financial pressure for students.

The effect of splay elastic constant on the transmittance of fringe-field switching using a liquid crystal with positive dielectric anisotropy (유전율 이방성이 양인 액정을 사용한 FFS 모드에서의 스플레이 탄성상수에 따른 투과율 연구)

  • Kim, Tae-Hyun;Lee, Ji-Youn;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.518-519
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    • 2005
  • We have studied the transmittance of fringe-filed switching(FFS) using a liquid crystal with positive dielectric anisotropy. Generally, FFS having positive dielectric anisotropy has less transmittance than FFS using negative dielectric anisotropy. FFS mode transmittance depends on horizontal director deformation, however fringe filed is composed of vertical and horizontal field. Vertical field in the middle of electrode suppresses the transmittance of FFS mode, especially when we use positive one. So, it is important to prevent the LC director from the effect of vertical field. We changed the splay elastic constant and checked the transmittance. The transmittance of FFS having positive dielectric anisotropy was improved. Less tilted LC directors improve the transmittance of FFS using positive dielectric anisotropy. We can improve the transmittance by using LC which have high splay elastic constant when another LC properties are equal.

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Electro-Optical Characteristics of the UV Aligned LCD Cell (UV 배향된 액정셀에서의 전기광학 특성)

  • Lee, Byung-Soon;Lee, Ho-Young
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.4
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    • pp.223-226
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    • 2013
  • In this study, we investigated the electro-optical(EO) characteristic of fringe-field switching(FFS) mode cell by the two kinds of ultraviolet(UV) alignment method on the organic thin film(polyimide: PI). The suitable organic layersfor FFS cell and the aligning capabilities of nematic liquid crystal(NLC) using the in-situ photoalignment method were studied Disclination is observed after conventional photoalignment method for 1h, and in-situ photoalignment method for 1h. Monodomain alignment of the NLC can be observed via in-situ photoalignment method for 2h and 3h. It is considered that NLC alignment is due to photo-depolymerization of the polymer with oblique non-polarized UV irradiation on PI surface. An unstable V-T curve of UV-aligned FFS-LCD with conventional photoalignment method can be achieved. However, a stable V-T curve of UV-aligned FFS-LCD with in-situ photoalignment method(1h), and V-T curve of UV-aligned FFS-LCD with in-situphotoalignment method was much stable comparing with that of other UV-aligned FFS-LCD's. As a result, more stable EO performanceof UV-aligned FFS-LCD with in-situphotoalignment method for 3h is obtained than that of the other UV-aligned FFS-LCD's.

Dual Domain Effect on a Rubbing Mura in a Fringe-Field Switching (FFS) Liquid Crystal Display

  • Oh, S.M.;Jeon, Y.M.;Lee, S.H.;Eom, T.Y.;KIM, H.Y.;LIM, Y.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.426-429
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    • 2005
  • The fringe-field switching (FFS) mode associated with a transition from a homogenously aligned to twist deformation require rubbing process. In this devices, $1^o$ of misalignment in an azimuthal direction could cause voltage-dependent transmittance (V-T) to be different from that in a normal area and consequently results in a rubbing mura. According to our studies, the single domain FFS cells are much more sensitive to the rubbing mura than the dual domain FFS cell. Moreover, the FFS cells with negative LC are much more sensitive to the rubbing mura than the FFS cells with positive LC.

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Economic Length of Stay and Opportunity Income of Appendectomy and Pneumonia Using Activity-based Costing (활동기준원가를 이용한 충수절제술과 폐렴의 경제적 재원일과 재원일 단축에 따른 기회이익)

  • Kim, Sang Mi;Lee, Hae Jong;Shin, Dong Gyo
    • Health Policy and Management
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    • v.23 no.2
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    • pp.124-131
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    • 2013
  • Background: This study aimed to measure the opportunity income by identifying the economic length of stay (ELOS) which is the intersection point of daily revenue and cost on appendectomy and pneumonia cases. Methods: The research subjects were 460 patients of appendectomy and 606 patients of pneumonia, discharged from a general hospital between July 1, 2009 and June 30, 2010. ELOS calculated with both of total revenue on diagnosis-related group (DRG) and fee-for service (FFS). The cost is calculated by activity-based costing system of the hospital. Results: Average length of stay (ALOS) of appendectomy was 4.48 days and its average revenue per case were 1,710,215 (1,989,105) won by DRG (FFS). The variable cost was 491,262 won which was 28.7% (24.7%) of DRG (FFS) total revenue. And 97.2% of the total variable cost was incurred within 2 days from admission. The ELOS was 4 (5) days in DRG (FFS). Shortening three days (two days) would increase opportunity income 52.0% (82.2%) in DRG (FFS). ALOS of pneumonia case was 4.86 days and its average revenue per case were 489,448 (761,426) won by DRG (FFS). The variable cost was 27,230 won which was 5.6% (3.6%) of DRG (FFS) total revenue. Thirty-eight point nine percent of the daily variable cost was incurred in discharge date. The ELOS was 2 (4) days in DRS (FFS). Shortening three days (one day) would increase opportunity income 27.6% (37.2%) in DRG (FFS). Conclusion: The ELOS would be used by strategic index for achieving minimum profit and developing the ways to get there. But we also should not pass over that the opportunity income obtained by the reducing ALOS may cause some problem of quality.

A Study on Electro-optical Characteristics of the UV Aligned FFS Cell on the Organic Layer

  • Han, Jeong-Min;Ok, Chul-Ho;Hwang, Jeoung-Yeon;Kim, Byoung-Yong;Kang, Dong-Hun;Kim, Jong-Hwan;Kim, Young-Hwan;Han, Jin-Woo;Lee, Sang-Keuk;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.3
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    • pp.135-138
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    • 2007
  • In this study, we investigated the electro-optical (EO) characteristic of fringe-field switching (FFS) mode cell by the two kinds of ultraviolet (UV) alignment method on the organic thin film (polyimide: PI). The suitable organic layers for FFS cell and the aligning capabilities of nematic liquid crystal (NLC) using the in-situ photoalignment method were studied; Disclination is observed after conventional photoalignment method for 1h, and in-situ photoalignment method for 1h. Monodomain alignment of the NLC can be observed via insitu photo alignment method for 2 h and 3 h. It is considered that NLC alignment is due to photo-depolymerization of the polymer with oblique non-polarized UV irradiation on PI surface. An unstable V-T curve of UV-aligned FFS-LCD with conventional photoalignment method can be achieved. However, a stable V-T curve of UV-aligned FFS-LCD with in-situ photoalignment method (1 h), and V-T curve of UV-aligned FFS-LCD with in-situ photo alignment method was much stable comparing with that of other UV-aligned FFSLCD's. As a result, more stable EO performance of UV-aligned FFS-LCD with in-situ photoalignment method for 3h is obtained than that of the other UV-aligned FFS-LCD's.

Survey on the Patterns of Fortified Food Consumption and Intake of Vitamins and Minerals in Fortified Foods by Elementary School and Middle-School Students in Korea (우리나라 일부 초등학생과 중학생의 영양강화식품 섭취 실태 및 영양강화식품을 통한 비타민과 무기질 섭취량 조사)

  • Kim, Sun-Hyo
    • Journal of the Korean Society of Food Culture
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    • v.26 no.3
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    • pp.295-306
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    • 2011
  • This study was performed to investigate patterns of fortified food (FF) consumption and intake of vitamins and minerals from FFs among 577 Korean children (12.4 years of age) who attended elementary or middle school. FFs eaten by children as a snack were surveyed using the food record method during 3 days, including 2 week days and one weekend. As a result, 114 FF items were eaten by the children, and several kinds of nutrients such as vitamin A, D, E, B complex, C, calcium (Ca), iron (Fe), and zinc (Zn) were fortified in these foods. Ca-FFs (65.8%) were most frequently consumed, followed by vitamin C-FFs (33.4%) and vitamin D-FFs (33.3%). The number of FF items in each food group was the most in the milk group (n=24, 21.0%), followed by the beverage group (n=19, 16.7%), and the cookie/bread/cake group (n=17, 14.9%). Fortified nutrients in FFs were in various combinations, but the major combination patterns were Ca, Ca plus vitamins, Ca plus vitamins plus other minerals, and Ca plus other minerals. Daily mean intakes of vitamins and minerals from the FFs were 66-300% more than those of the recommended nutrient intake (RNI ) or adequate intake (AI) for most vitamins and minerals. Daily maximum intakes (95th percentile) of vitamins and minerals from FFs were 1-15 times the RNI or AI for most vitamins and minerals. Vitamin and mineral consumption ratios from each FF group were different according to the kind of fortified nutrient. For example, vitamin C was mostly eaten in fortified beverages (46-54%), and Fe was mostly eaten in fortified cookie/breads/cakes (87%). The above results show that FF consumption varied widely among the children, and that most of the children's foods were fortified with several vitamins and minerals without a common rule; thus, subjects risked over consuming vitamins and minerals by eating FFs. Therefore, practical guideline on FF use for children's optimal nutrition and health should be provided through nutrition education.