• International Journal of Air-Conditioning and Refrigeration
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• 제13권4호
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• pp.196-205
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• 2005

In this paper, recent research trend on heat transfer in impinging jet is reviewed. We focused on submerged jet that air issued into air or liquid issued into liquid. To control and enhance the heat transfer in single jet, researchers have performed a lot of experiments by considering the nozzle geometry, impinging surface and active method such as jet vibration, secondary injection and suction flow. The studies on multiple jet have been mainly focused on finding out the optimum condition and on investigating many different factors concerned with application condition (crossflow, rotation and geometry etc.) and combined techniques (rib turbulator, pin fin, dimple and effusion hole etc.). All most experiments showed the detailed heat transfer data by using liquid crystal method, infrared camera technique and naphthalene sublimation method. Many numerical calculations have been performed to investigate the flow and heat transfer characteristics in laminar jet region. Various turbulence models such as $k-\varepsilon-\bar{\nu^2}$, modified $k-\varepsilon-f_{\mu}$ were applied to the calculation for turbulent jet and the predicted results showed a good agreement with the experimental data. Although a lot of studies on impinging jet have performed consistently up to recently, further studies are still required to understand the flow and heat transfer characteristics more accurately, and to give a guideline for optimum impinging jet design in various applications.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.891-897
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• 2021

In this paper, we propose a destination optimal route algorithm for providing route finding service for the transportation handicapped by using the multi-criteria decision-making technique and the modified A-STAR optimal route search algorithm. This is a method to set the route to the destination centering on safety by replacing the distance cost of the existing A-STAR optimal route search algorithm with the safety cost calculated through AHP/TOPSIS analysis. To this end, 10 factors such as road damage, curb, and road hole were first classified as poor road factors that hinder road driving, and then pairwise comparison of AHP was analyzed and then defined as the weight of TOPSIS. Afterwards, the degree of driving safety was quantified for a certain road section in Busan through TOPSIS analysis, and the development of an optimal route search algorithm for the transportation handicapped that replaces the distance cost with safety in the finally modified A-STAR optimal route algorithm was completed.

• 동아시아경상학회지
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• 제11권4호
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• pp.11-18
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• 2023

Purpose - By filling the existing research hole and supplying a whole evaluation, this test wants to offer actionable insights for stakeholders navigating the intersection of sustainability and financial prosperity. Ultimately, this study contributes to the evolving speak on ESG, fostering a deeper comprehension of its implications for fostering sustainable economic increase. Research design, data, and methodology - Based on the numerous prior literature, the current study adopts a rigorous and systematic approach to discover the connection between Environmental, Social, and Governance (ESG) performance and its effect on a financial boom. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method is the guiding framework for systematically accumulating and analyzing earlier research studies. Result: The finding of this study indicates that using ESG-pushed innovation, practitioners can force technological advancements inside their respective industries. By combining sustainability with research and improvement tasks, corporations can be leaders in selling economic boom through current, green solutions. Conclusion - In summary, this study concludes that embracing those findings in this study allows practitioners and managers to enhance their organization's easy regular, well-known traditional regular standard overall performance and undoubtedly contribute to a broader financial boom via leveraging the transformative strength of ESG necessities.

• 방송공학회논문지
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• 제26권6호
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• pp.714-724
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• 2021

포인트 클라우드 콘텐츠는 실제 환경 및 물체를 3차원 위치정보를 갖는 점들과 그에 대응되는 색상 등을 획득하여 기록한 실감 콘텐츠이다. 위치와 색상 정보로 구성된 3차원 점으로 이루어진 포인트 클라우드 콘텐츠는 확대하여 렌더링 할 경우 점과 점 사이의 간격이 벌어지면서 빈 구멍이 발생하게 된다. 본 논문에서는 포인트 클라우드 확대 시 점들 간 간격이 벌어져 생기는 구멍을 찾고 구멍에 대해 깊이정보를 활용한 역 변환 기반 보간 방법을 통해 포인트 클라우드 콘텐츠 품질을 개선하는 방법을 제안한다. 영상의 확대나 카메라 근접 등으로 포인트들의 간격이 벌어지면 틈이 생기면서 구멍 사이에 뒷면의 포인트들이 렌더링 되어 보간 방법을 적용하는데 방해요소로 작용한다. 이를 해결하기 위해 포인트 클라우드의 뒷면에 해당하는 점들을 제거한다. 다음으로 빈 구멍이 발생한 시점의 깊이 맵(depth map)을 추출한다. 마지막으로 역 변환을 하여 원본의 데이터에서 픽셀을 추출한다. 제안하는 방법으로 콘텐츠를 렌더링한 결과, 기존의 크기를 늘려 빈 영역을 채우는 방법에 비해 렌더링 품질이 평균 PSNR 측면에서 1.2 dB 향상된 결과를 보였다.

• 한국초전도ㆍ저온공학회논문지
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• 제26권2호
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• pp.9-18
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• 2024

The current study deals with the possible interplay between superconductivity and spin density wave in two band model high temperature iron based superconductor (FeBSC) Ba_1-xNa_xFe₂As₂. The electron and hole bands in the presence of the inter-band interaction between the two bands is becoming a vital issue to deal with the high temperature physics of the iron-based superconductors. In this research work, a model Hamiltonian appropriate for the system under consideration has been developed and the temperature dependent Green's function technique has been employed to get the solution for the equations of motion constructed for the two band model high temperature FeBSC Ba_1-xNa_xFe₂As₂. By making use of the decoupling procedure, the equations of motion for the dependence of superconducting transition temperature (T_C) on spin density wave(SDW) order parameter (Δ_SDW) in the electron intra-band (Δ_sc(e)) , hole intra-band (Δ_sc(h)) and inter-band (Δ_sc(eh)) for Ba_1-xNa_xFe₂As₂ have been obtained. We have also obtained the expression for the dependence of spin density wave transition temperature(T_SDW) on Δ_SDW for Ba_1-xNa_xFe₂As₂. Using some plausible approximations and appropriate experimental values for the parameters in the obtained equations of motion, phase diagrams of T_C versus Δ_sc(e), Δ_sc(h) and Δ_sc(eh) are plotted. Furthermore, a phase diagram of T_SDW versus Δ_SDW is plotted for the material under consideration. Finally, using the above mentioned phase diagrams, the interplay between superconductivity and spin density wave in the two band model high temperature FeBSC Ba_1-xNa_xFe₂As₂ has been demonstrated to be a very distinct possibility. The agreement of the current finding with the experimental observations is quite commendable.

• 패션비즈니스
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• 제5권2호
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• pp.129-147
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• 2001

The purpose of this study is to survey and analyze domestic fashion education institution's program on apparel prototype and thereupon, address the problems and find their solutions, and thereby, provide for some basic data useful to improve the basic patterns of apparel and ultimately, help reinforce the professional and practical apparel design education. The results of this study can be summarized as follows; 1. 85.1% of the subjects finished graduate or higher courses. Almost all of the college and junior college teachers finished graduate or higher courses, while only 31.6% of those teaching at technical institutes finished graduate or higher courses. Such a finding suggests that colleges tend to employ their faculty members based on their academic background but that technical institutes value the practical ability of their faculty more. 2. As a result of surveying the types of basic patterns used by teachers, it was found that 72.3% of them were using two or more patterns. The basic pattern preferred most by our teachers was Japanese culture institute's type (71.3%), followed by the US FIT type (24.5%), Lim Won-Ja's type (22.3%), French ESMOD type (17.0%). 96.3% of our apparel design students were making their basic patterns as instructed by their teachers. 3. 67.0% of our students were using their conceived sizes for production of their basic patterns, 14.9% were referring to the ready-made sizes, 8.5% were relying on their teachers' individual experiences, and 9.6% were using their own cord sizes. In order to survey the difference between teachers' sizes (ready-made sizes or individual experienced ones) and business sizes used, the basic body measurements used for ready-made apparels were surveyed to be compared with the national standard body sizes set in 1997 for women aged between 18 and 24. As a result, it was found that the ready-made sizes used for apparel production prototypes than teachers' ones were nearer the national standard sizes. Such a finding suggests that it may well be necessary for teachers to be more connected with the apparel businesses and thereby, teach their students in a more realistic way with correct information. 4. 83.0% of the subject teachers were tacking their basic patterns to be well fitting, and 76.9% of these teachers were tacking the patterns in reference with students' individual body sizes. In all, 97.4% of the subject teachers were guiding the tacking process, which suggests that the flat patternmaking is taught primarily for customized apparels. As a result of comparing the fitness of basic patterns with those of each body part, it was found that teachers were most dissatisfied with the fitness of shoulders and arm hole depth. Therefore, it will be necessary to reclassify the body types or find other drawing techniques to improve the fitness of such body parts. Nevertheless, teachers were willing much (4.18) to develop their own educational basic patterns for themselves. Lastly, it is hoped that this study will be followed up by future studies on educational prototypes covering diverse body shapes and those on practical implementations of those prototypes for students.

• 한국정밀공학회지
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• 제27권1호
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• pp.125-133
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• 2010

A versatile micro-robotic platform for micro/nano scale assembly has been demanded in a variety of application areas such as micro-biology and nanotechnology. In the near future, a flexible and compact platform could be effectively used in a scanning electron microscope chamber. We are developing a platform that consists of miniature mobile robots and a compact positioning stage with multi degree-of-freedom. This paper presents the design and the implementation of a low-cost and compact multi degree of freedom position sensor that is capable of measuring absolute translational and rotational displacement. The proposed sensor is implemented by using a CMOS type image sensor and a target with specific hole patterns. Experimental design based on statistics was applied to finding optimal design of the target. Efficient algorithms for image processing and absolute position decoding are discussed. Simple calibration to eliminate the influence of inaccuracy of the fabricated target on the measuring performance also presented. The developed sensor was characterized by using a laser interferometer. It can be concluded that the sensor system has submicron resolution and accuracy of ${\pm}4{\mu}m$ over full travel range. The proposed vision-based sensor is cost-effective and used as a compact feedback device for implementation of a micro robotic platform.

• 한국터널지하공간학회 논문집
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• 제8권2호
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• pp.129-139
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• 2006

두개의 장약공에 시차를 주고 발파할 경우 파의 특징인 상호 간섭현상이 발생한다. 이러한 파의 간섭현상은 중첩을 통하여 파가 서로 증폭이 되거나 상쇄가 된다. 따라서 이러한 파의 특성을 이용하여 시험발파 시 단공발파를 통한 발파진동 데이터를 측정하여 각각의 파형을 합성한 뒤 최적지연초시를 찾고 이 합성초시를 전단면에 적용하여 그 효율성을 입증하는데 이번 실험의 목적이 있다. 기존뇌관(비전기, 전기뇌관)의 정형화된 초시(20, 25ms)가 아닌 현장암질에 적합한 전자뇌관의 최적초시를 도출하여 발파 진동을 최소화 하고 굴착효율을 높이는 발파 굴착공법의 개발을 모색하고 시험시공을 통한 현장 적용성을 평가하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제18권3호
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• pp.191-200
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• 2014

We investigated the anxiolytic-like activity of ${\alpha}$-asarone (AAS) from Acorus gramineus in an experimental rat model of anxiety induced by repeated administration of the exogenous stress hormone corticosterone (CORT). The putative anxiolytic effect of AAS was studied in behavioral tests of anxiety, such as the elevated plus maze (EPM) test and the hole-board test (HBT) in rats. For 21 consecutive days, male rats received 50, 100, or 200 mg/kg AAS (i.p.) 30 min prior to a daily injection of CORT. Dysregulation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Daily AAS (200 mg/kg) administration increased open-arm exploration significantly in the EPM test, and it increased the duration of head dipping activity in the HBT. It also blocked the increase in tyrosine hydroxylase (TH) expression in the locus coeruleus (LC) and decreased mRNA expression of brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, in the hippocampus. These results indicated that the administration of AAS prior to high-dose exogenous CORT significantly improved anxiety-like behaviors, which are associated with modification of the central noradrenergic system and with BDNF function in rats. The current finding may improve understanding of the neurobiological mechanisms responsible for changes in emotions induced by repeated administration of high doses of CORT or by elevated levels of hormones associated with chronic stress. Thus, AAS did exhibit an anxiolytic-like effects in animal models of anxiety.

• Journal of Ecology and Environment
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• 제41권1호
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• pp.9-18
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• 2017

Background: Species in the heterokont genus Synura are colonial and have silica scales whose ultrastructural characteristics are used for classification. We examined the ultrastructure of silica scales and molecular data (nuclear SSU rDNA and LSU rDNA, and plastid rbcL sequences) to better understand the taxonomy and phylogeny within the section Petersenianae of genus Synura. In addition, we report the first finding of newly recorded Synura species from Korea. Results: We identified all species by examination of scale ultrastructure using scanning and transmission electron microscopy (SEM and TEM). Three newly recorded species from Korea, Synura americana, Synura conopea, and Synura truttae were described based on morphological characters, such as cell size, scale shape, scale size, keel shape, number of struts, distance between struts, degree of interconnections between struts, size of base plate pores, keel pores, base plate hole, and posterior rim. The scales of the newly recorded species, which belong to the section Petersenianae, have a well-developed keel and a characteristic number of struts on the base plate. We performed molecular phylogenetic analyses based on sequence data from three genes in 32 strains (including three outgroup species). The results provided strong statistical support that the section Petersenianae was monophyletic, and that all taxa within this section had well-developed keels and a defined number of struts on the base plate. Conclusions: The phylogenetic tree based on sequence data of three genes was congruent with the data on scale ultrastructure. The resulting phylogenetic tree strongly supported the existence of the section Petersenianae. In addition, we propose newly recorded Synura species from Korea based on phylogenetic analyses and morphological characters: S. americana, S. conopea, and S. truttae.