A Novel Design of Suspension System for Driver's Seat

Thanh-Tung Luu(Thanh-Tung Luu),박성태(Sung-Tae Park) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.5_2

A driver's seat can be modeled with a suspension system of spring, mass and damper. To increase the capacity of anti-vibration, the natural frequency should be decreased as low as possible. In this paper, the method to decrease the natural frequency by the potential energy is introduced. In addition, the experiment is done on a small model to prove the theorem.

Propensity to Innovate and Firm Performance in the Developing Economies: Evidence from ASEAN Countries

Duy Tran Luu,Truong Vinh Tran Luu 아시아기술혁신학회 2023 Asian Journal of Innovation and Policy Vol.12 No.2

This paper employs datasets from the Enterprise Survey conducted by the World Bank to examine the relationship between four types of innovation defined by the Oslo Manual (OECD, 2005): product innovation, process innovation, marketing innovation, organization innovation, and the firm performance in the selected developing ASEAN economies. The main objective of this paper is to understand the characteristics of innovation activities at the firm level and how various innovation types affect firm performance. The empirical results from ASEAN manufacturing firms reveal that product innovation positively affects firms’ performance, while non-technological innovations are negatively related to the performance of firms. The further employed quantile regression provides more insights into the roles of innovation types on different levels of firm performance: while product and process innovations actively contribute to the small and medium-size firms (below 25th quantile and median), organizational and marketing innovations negatively affect them. Interestingly, the role of process innovation decreases when firm performance grows.

Effect of thickness on the microstructure and soft magnetic properties of CoFeHfO thin films

Luu Van Tho,이광은,김철기,김종오 한국물리학회 2008 Current Applied Physics Vol.8 No.6

The thickness effects on the microstructure and soft magnetic properties of CoFeHfO thin films have been investigated in the range of 100–600 nm. There was a significant change in the coercivity (Hc) and the anisotropy (Hk) value with increasing film thickness, but the saturation induction and the resistivity almost remain unchanged. Hc and Hk reached a minimum value of 0.19 Oe and a maximum value of 50 Oe, respectively at 200 nm film thickness. The high saturation magnetic induction is 21 kG and resistivity is 500μΩ cm. The origin of the changing Hc and Hk values is discussed in detail based on change of microstructure along with film thickness. The thickness effects on the microstructure and soft magnetic properties of CoFeHfO thin films have been investigated in the range of 100–600 nm. There was a significant change in the coercivity (Hc) and the anisotropy (Hk) value with increasing film thickness, but the saturation induction and the resistivity almost remain unchanged. Hc and Hk reached a minimum value of 0.19 Oe and a maximum value of 50 Oe, respectively at 200 nm film thickness. The high saturation magnetic induction is 21 kG and resistivity is 500μΩ cm. The origin of the changing Hc and Hk values is discussed in detail based on change of microstructure along with film thickness.

Investigation of the Microstructure of Mechanically Milled Nd40Fe30Co15Al10B5 Alloy

Luu Tien Hung,Nguyen Huy Dan 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

The microstructure of Nd40Fe30Co15Al10B5 alloys fabricated by using a high-energy ball-milling method was investigated by using high-resolution transmission electron microscopy (HRTEM), scan- ning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), selected area electron diraction (SAED) and electron backscatter diraction (EBSD) techniques. The crystalline phases found in the alloys were the tetragonal Nd2(Fe,Co,Al)14B (denoted as the 2 : 14 : 1 phase), the tetragonal Nd6(Fe,Co,Al)14 (denoted as the phase) and the fcc Nd-rich (a = 0.51 nm) phases. The formation of 2 : 14 : 1 crystallites supposedly contributed to the high coercivities up to 24 kOe for the alloys. The microstructure of Nd40Fe30Co15Al10B5 alloys fabricated by using a high-energy ball-milling method was investigated by using high-resolution transmission electron microscopy (HRTEM), scan- ning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), selected area electron diraction (SAED) and electron backscatter diraction (EBSD) techniques. The crystalline phases found in the alloys were the tetragonal Nd2(Fe,Co,Al)14B (denoted as the 2 : 14 : 1 phase), the tetragonal Nd6(Fe,Co,Al)14 (denoted as the phase) and the fcc Nd-rich (a = 0.51 nm) phases. The formation of 2 : 14 : 1 crystallites supposedly contributed to the high coercivities up to 24 kOe for the alloys.

KHẢO SÁT TÌNH HÌNH ĐÀO TẠO PHIÊN DỊCH VIÊN Y TẾ HÀN-VIỆT TẠI HÀN QUỐC

LUU THI SINH 한국베트남학회 2023 베트남연구 Vol.21 No.2

Mục đích của bài nghiên cứu này là nhằm khảo sát tình hình đào tạo phiên dịch viên Y tế Hàn-Việt tại Hàn Quốc. Bài nghiên cứu đã đưa ra tài liệu thống kê cụ thể về số người Việt Nam sử dụng dịch vụ y tế tại Hàn Quốc trong những năm gần đây. Qua đó, độc giả có thể hình dung ra thực tế, tương lai của lĩnh vực dịch vụ này và cũng có thể nhận thấy sự cần thiết của việc đào tạo phiên dịch viên Hàn-Việt cho ngành Y tế. Phần trọng tâm của bài nghiên cứu đã hướng vào việc khái quát hoá quá trình hình thành khoá đào tạo và phân tích, đánh giá về thiết kế môn học. Đặc biệt, bài nghiên cứu đã tập trung vào các yếu tố có ảnh hưởng trực tiếp đến chất lượng đào tạo như: tài liệu học tập (giáo trình, từ điển, tài liệu tham khảo bằng văn bản, âm thanh, hình ảnh), đội ngũ giảng viên, thời gian và địa điểm học, trình độ sử dụng ngoại ngữ của học viên, v.v.. Cuối cùng, bài nghiên cứu đưa ra một số khuyến nghị để có thể cải thiện chất lượng của khoá đào tạo và nâng cao kĩ năng phiên dịch cho các học viên, góp phần tăng cường giao lưu trong lĩnh vực y tế và thúc đẩy mối quan hệ ngày càng đa dạng giữa hai nước Hàn Quốc và Việt Nam.

Automatic Suggestion for PubMed Query Reformulation

Luu Anh Tuan,Jung-jae Kim 한국정보과학회 2012 Journal of Computing Science and Engineering Vol.6 No.2

Query reformulation is an interactive process of revising user queries according to the query results. To assist biomedical researchers in this process, we present novel methods for automatically generating query reformulation suggestions. While previous work on query reformulation focused on addition of words to user queries, our method can deal with three types of query reformulation (i.e., addition, removal and replacement). The accuracy of the method for the addition type is ten times better than PubMed’s “Also try”, while the execution time is short enough for practical use.

Effect of mammography screening on the long-term survival of breast cancer patients: results from the National Cancer Screening Program in Korea

Luu Xuan Quy,Lee Kyeongmin,Jun Jae Kwan,Suh Mina,Jung Kyu-Won,최귀선 한국역학회 2022 Epidemiology and Health Vol.44 No.-

OBJECTIVES: This study investigated the effect of mammography screening on the long-term survival of breast cancer (BC) patients aged 40 years or older according to their screening history and duration since screening. METHODS: The study cohort was organized from 3 nationwide databases of the Korean National Cancer Screening Program, the Korean Central Cancer Registry, and death certificates. We included 24,387 women diagnosed with invasive BC or ductal carcinoma in situ in 2008 and 2009 and followed up until December 31, 2019. Cox proportional-hazards regression was used to investigate the effect of BC screening on the risk of death. RESULTS: Overall, 20,916 of 24,387 patients (85.8%) were alive at the end of the follow-up period (median: 10.5 years). The long-term survival rate was significantly lower in the never-screened group (80.3%) than in the screened group (88.9%) (p< 0.001). A 35% reduction in the risk of BC death (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.60 to 0.70) from screening was observed. A subgroup analysis according to the cancer stage showed 62%, 36%, and 24% lower risks of BC death for the localized stage, regional stage, and distant stage, respectively. Women aged 40-49 years received the least benefit from BC screening (HR, 0.71; 95% CI, 0.62 to 0.81). CONCLUSIONS: Mammography screening was effective in reducing the risk of BC-specific death in Asian women across all cancer stages. However, this effect was relatively small among women in their 40s, suggesting that more detailed and specialized screening strategies are needed for that age group.

Exploration of Essential Structure of Malloapelta B for the Inhibitory Activity Against TNF Induced $NF-{\kappa}B$ Activation

Luu, Chinh Van,Chau, Minh Van,Lee, Jung-Joon,Jung, Sang-Hun The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.10

For the exploration of pharmacophoric moiety of malloapelta B (1) possessing the inhibitory activity of $NF-{\kappa}B$ activation, structural variation of ${\alpha},{\beta}-unsaturated$ carbonyl motif was attempted. 1 was reduced by catalytic hydrogenation, sodium borohydride, and lithium aluminumhydride. Catalytic hydrogenation with 30 psi or 15 psi of $H_2$ gas of 1 generated 8-butyl-5,7-dimethoxy-2,2-dimethylchroman (2) and 1-(5,7-dimethoxy-2,2-dimethylchroman-8-yl)butan-1-one (3), respectively. Reduction with sodium borohydride occurred at the double bond of ${\alpha},{\beta}-unsaturated$ ketone of 1 to give 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)butan-1-one (4). Reduction of 1 with lithium aluminumhydride and then quenched with methanol and water produced unexpected products, 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)-3-methoxy-1-butene (5) and 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)-3-hydroxy-1-butene (6). These are formed from the isomerization of initial product 9 through the continuous conjugate carbocation intermediate 11. Addition of ethylmagnesium bromide and dimethyl malonate anion to 1 gave the conjugate adducts 7 and 8. Ethylmagesium bromide and sodium borohydride reduction unusually gave the conjugate addition due to steric congestion around carbonyl group of 1. Compound 2 exhibits the reduced inhibitory activity against $NF-{\kappa}B$ activation and the others do not show the activity. Therefore ${\alpha},{\beta}-unsaturated$ carbonyl group of 1 should be important for its inhibitory activity.

Mesoporous Carbon-Silica Janus Nanoparticles for Environmental Application and Heterogenous Catalyst in SABRE Hyperpolarization

( Luu Son Quy ),이영복 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.0

A full utilization of Space-time block code in Cooperative Communication

Luu Quoc Tin,Hyung Yun Kong 한국통신학회 2007 한국통신학회 학술대회논문집 Vol.2007 No.11