• Journal of the Optical Society of Korea
• /
• 제11권3호
• /
• pp.124-129
• /
• 2007

For the first time we compare two kinds of optical frequency combs, one of which is based on a Ti:sapphire femtosecond laser and the other is based on a mode-locked erbium-doped fiber laser. The comparison is performed by measuring an optical frequency standard with these two combs simultaneously. The two frequency measurements agree within 1.8 Hz ($3.8{\times}10^{-15}$) with the uncertainty of 17.2 Hz ($3.6{\times}10^{-14}$), from which it can be concluded that the Ti:sapphire-based frequency comb and the fiber-based frequency comb have no systematic discrepancy at this level of uncertainty.

• Tribology and Lubricants
• /
• 제30권6호
• /
• pp.323-329
• /
• 2014

The friction-reducing properties of lubricants containing ionic liquids based on ammonium dithiocarbamate are studied. The ionic liquids are produced through the following two steps: the synthesis of sodium alkyl dithiocarbamates via the substitution reaction of dialkylamine and carbon disulfide and their subsequent conversion into ammonium dithiocarbamate-based ionic liquids through an ion-exchange reaction with a quaternary alkyl ammonium halide salt. The structures of the ionic liquids are characterized by NMR spectroscopy and Fourier transform infrared spectroscopy. The isolated yields of the ionic liquids, which are viscous and pale yellow, are approximately 92%. The Brookfield viscosities and pour points of the ionic liquids are determined. Further, their wear resistances are measured through the four-ball wear test and the Schwingung Reibung Ver-schleiss (oscillation, friction, wear) test. The wear scar diameter of the lubricants containing 1 wt of the quaternary alkyl ammonium dithiocarbamate-based ionic liquids (0.475-0.631 mm) is significantly lower than that of the base oil (0.825 mm), proving that the ammonium dithiocarbamate-based ionic liquids have good friction-reducing characteristics. However, these friction-reducing characteristics fade significantly after long-term storage, owing to the degradation of the ionic liquids.

• Tribology and Lubricants
• /
• 제30권5호
• /
• pp.256-264
• /
• 2014

Enhancing the value of fine chemicals based on biomass resources is an important objective for addressing environmental and other concerns such as demand for renewable or green products, as well as from the political perspective to reduce dependence on fossil feedstock associated with the use of petroleum-based products. Based on these considerations, we studied the synthesis of estolide using waste plant-based oil materials and their application as lubricants and pour point depressants. Five estolides were prepared by varying molar ratio of palmitic acid (PA) to oleic acid (OA) using a reaction time of 48 h. The estolides were characterized by size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR). The isolated yields were in the range of 57-78 % and purity was 93-97%, showing iodine values of 18.2-37.8, total acid numbers (TANs) of 75.6-94.2 mg KOH/g and estolide numbers (ENs) of 1.2-1.8. Increasing the ratio of OA to PA in the synthesis decreased the kinematic viscosity and clouding point of the estolides. Four ball wear test of the estolides as a base oil demonstrated that the wear scar diameter (WSD) of the estolides was significantly lower (0.320-0.495 mm) than the WSD of general base oils such as 150N and Yubase (0.735 and 0.810 mm, respectively), indicating better wear resistance of the estolides. However, the lubricant property was found to be independent of the amount of OA in the estolides. These new materials are prospective candidates for application as a lubricant base oil.

• Perspectives in Nursing Science
• /
• 제4권1호
• /
• pp.19-25
• /
• 2007

Systems and processes to provide clinical education to students of nursing have been established between universities and health facilities in all countries where nurse education is tertiary based. However, systems and processes to link nurse researchers based in universities to their clinical colleagues are less well developed. When collaborations are established they are frequently based on personal networks, and while the rhetoric of the organizations encourages these collaborations, they are largely unrecognised by senior administrators in health facilities. The research is frequently "invisible" and the clinician researchers usually do not have access to appropriate infrastructure and other resources that are required to support large projects that have the potential to change practice across organisations. This situation influences the focus and scope of nursing research and limits opportunities for clinicians to be engaged in the generation of professional knowledge. The University of Western Sydney (UWS) has taken a strategic approach to the development of collaborations for research and has linked with health services in Western Sydney to establish and maintain research centres and adjunct appointments. The partner organisations jointly fund the infrastructure of the centres which include a Professor, research assistant position(s) and administrative staff. Five Professors of Nursing have been appointed to positions in one of three nursing research centres. This paper describes the approach established by the School of Nursing at UWS to build collaborations with clinical areas to promote research. This approach could be adopted or adapted by other facilities.

• ETRI Journal
• /
• 제41권2호
• /
• pp.242-253
• /
• 2019

We devise a layer-wise hint training method to improve the existing hint-based knowledge distillation (KD) training approach, which is employed for knowledge transfer in a teacher-student framework using a residual network (ResNet). To achieve this objective, the proposed method first iteratively trains the student ResNet and incrementally employs hint-based information extracted from the pretrained teacher ResNet containing several hint and guided layers. Next, typical softening factor-based KD training is performed using the previously estimated hint-based information. We compare the recognition accuracy of the proposed approach with that of KD training without hints, hint-based KD training, and ResNet-based layer-wise pretraining using reliable datasets, including CIFAR-10, CIFAR-100, and MNIST. When using the selected multiple hint-based information items and their layer-wise transfer in the proposed method, the trained student ResNet more accurately reflects the pretrained teacher ResNet's rich information than the baseline training methods, for all the benchmark datasets we consider in this study.

• ETRI Journal
• /
• 제44권4호
• /
• pp.599-612
• /
• 2022

This study focuses on improving a word embedding model to enhance the performance of downstream tasks, such as those of dialog systems. To improve traditional word embedding models, such as skip-gram, it is critical to refine the word features and expand the context model. In this paper, we approach the word model from the perspective of subword embedding and attempt to extend the context model by integrating various sentence models. Our proposed sentence model is a subword-based skip-thought model that integrates self-attention and relative position encoding techniques. We also propose a clustering-based dialog model for downstream task verification and evaluate its relationship with the sentence-model-based subword embedding technique. The proposed subword embedding method produces better results than previous methods in evaluating word and sentence similarity. In addition, the downstream task verification, a clustering-based dialog system, demonstrates an improvement of up to 4.86% over the results of FastText in previous research.

• 산경연구논집
• /
• 제14권7호
• /
• pp.1-7
• /
• 2023

Purpose: The present research is to explore and investigate the meaningful difference between job-based pay and skill-based pay in the current literature to shed light on the advantages and caveats of two compensation approach, providing direction for human resource practitioners looking to develop efficient and fair compensation plans. Research design, data and methodology: The methodology based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used for this research. The PRISMA technique is generally considered the gold standard since it guarantees openness, repeatability, and rigor. Studies comparing salaries based on work duties versus those based on individual skills published in English and accepted for publication in peer-reviewed journals are eligible for inclusion. Results: According to the comprehensive literature analysis, the present research provides clear comparison between Job-based pay and skilled-based pay, pointing out a similarity and four differences (1. Criteria for pay determination, 2. Flexibility, 2. Job Scope, and 4. Career progression. Conclusions: The result of the current research implies that human resource professionals would be well to learn the effects of various compensation structures on career advancement, and suggests for them that employees can take advantage of chances to advance in their careers based on right compensation schemes.

• ETRI Journal
• /
• 제46권2호
• /
• pp.277-289
• /
• 2024

In this paper, we describe a neural network-based application that recommends multiple items using dialog context input and simultaneously outputs a response sentence. Further, we describe a multi-item recommendation by specifying it as a set of clothing recommendations. For this, a multimodal fusion approach that can process both cloth-related text and images is required. We also examine achieving the requirements of downstream models using a pretrained language model. Moreover, we propose a gate-based multimodal fusion and multiprompt learning based on a pretrained language model. Specifically, we propose an automatic evaluation technique to solve the one-to-many mapping problem of multi-item recommendations. A fashion-domain multimodal dataset based on Koreans is constructed and tested. Various experimental environment settings are verified using an automatic evaluation method. The results show that our proposed method can be used to obtain confidence scores for multi-item recommendation results, which is different from traditional accuracy evaluation.

• International Journal of Contents
• /
• 제4권2호
• /
• pp.24-28
• /
• 2008

In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.

• 기술혁신학회지
• /
• 제9권4호
• /
• pp.654-687
• /
• 2006

본 연구는 연구기관에서 개발한 기술을 기반으로 창업한 연구기반 스핀오프 벤처기업의 성장단계 및 단계별 성공요인에 관한 이론 및 사례연구이다. 이론연구를 통해 연구기반 스핀오프 벤처기업의 성장단계는 일반 벤처기업의 개념화와 개발기, 상업화기, 성장기, 안정기로 구성되는 4단계 성장단계에 대비되는 단계가 있는 것으로 밝혀졌다. 연구기반 스핀오프 벤처기업은 1단계인 개념화와 개발기에는 연구결과로부터 사업 아이디어를 도출, 2단계인 상업화기에는 사업 아이디어로부터 도출된 것을 신규 벤처 프로젝트로 완결, 3단계인 성장기에는 신규 프로젝트로부터 스핀오픈 벤처기업을 출범, 4단계인 안정기에는 스핀오프 벤처기업에 의한 경제적 부의 창출 강화라는 성장단계가 있으며 단계별로 고유한 과제가 있는 것으로 나타났다. 사례연구로 정부출연연구소를 모태기관으로 하여 스핀오프로 창업한 벤처기업에 대한 분석을 하였다. 사례분석을 통해 연구기반 스핀오프 벤처기업은 각 단계별 고유한 과제의 해결이 이루어져야 다음 단계로의 성공적인 이행이 되는 것으로 나타났다 후반부에 본 논문의 시사점과 연구의 한계 및 향후 연구 방향에 대해 제시하였다.