• 한국재료학회지
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• 제22권7호
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• pp.358-361
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• 2012

Co and Ni as catalysts in $SnO_2$ sensors to improve the sensitivity for $CH_4$ gas and $CH_3CH_2CH_3$ gas were coated by a solution reduction method. $SnO_2$ thick films were prepared by a screen-printing method onto $Al_2O_3$ substrates with an electrode. The sensing characteristics were investigated by measuring the electrical resistance of each sensor in a chamber. The structural properties of $SnO_2$ with a rutile structure investigated by XRD showed a (110) dominant $SnO_2$ peak. The particle size of the $SnO_2$:Ni powders with Ni at 6 wt% was about 0.1 ${\mu}m$. The $SnO_2$ particles were found to contain many pores according to a SEM analysis. The sensitivity of $SnO_2$-based sensors was measured for 5 ppm of $CH_4$ gas and $CH_3CH_2CH_3$ gas at room temperature by comparing the resistance in air to that in the target gases. The results showed that the best sensitivity of $SnO_2$:Ni and $SnO_2$:Co sensors for $CH_4$ gas and $CH_3CH_2CH_3$ gas at room temperature was observed in $SnO_2$:Ni sensors coated with 6 wt% Ni. The $SnO_2$:Ni gas sensors showed good selectivity to $CH_4$ gas. The response time and recovery time of the $SnO_2$:Ni gas sensors for the $CH_4$ and $CH_3CH_2CH_3$ gases were 20 seconds and 9 seconds, respectively.

• 한국표면공학회지
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• 제37권5호
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• pp.249-252
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• 2004

Effects of HA and TiN coating on the electrochemical characteristics of Ti-6AI-4V alloys for bone plates were investigated using various test methods. Ti-6AI-4V alloys were fabricated by using a vacuum induction furnace and bone plates were made by laser cutting and polishing. HA was made of extracted tooth sintered and then tooth ash was used as HA coating target. The TiN and HA film coating on the surface were carried on using electron-beam physical vapor deposition (EB-PVD) method. The corrosion behaviors of the samples were examined through potentiodynamic method in 0.9% NaCI solutions at $36.5\pm$$1^{\circ}C$ and corrosion surface was observed using SEM and XPS. The surface roughness of TiN coated bone plates was lower than that of tooth ash coated plates. The structure of TiN coated layer showed the columnar structure and tooth ash coated layer showed equiaxed and anisotrophic structure. The corrosion potential of the TiN coated specimen is comparatively high. The active current density of TiN and tooth ash coated alloy showed the range of about $1.0xl0^{-5}$ $A\textrm{cm}^2$, whereas that of the non-coated alloy was$ 1.0xl0^{-4}$ $A\textrm{cm}^2$. The active current densities of HA and TiN coated bone plates were smaller than that of non-coated bone plates in 0.9% NaCl solution. The pitting potential of TiN and HA coated alloy is more drastically increased than that of the non-coated alloy. The pit number and pit size of TiN and HA coated alloy decreased in compared with those of non-coated alloy. For the coated samples, corrosion resistance increased in the order of TiN coated, tooth ash coated, and non-coated alloy.

• Journal of Power Electronics
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• 제17권4호
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• pp.1048-1057
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• 2017

An indirect matrix converter (IMC) is a modern power generation system that enables a direct ac/ac conversion without the need for any bulky and limited lifetime electrolytic capacitor. This system also allows four-quadrant operation, generation of sinusoidal output voltage waveforms with variable frequency and amplitude, and control of input power factor. This study proposes a pulse-width modulation-based sliding-mode controller to achieve unity input-power factor operation of the IMC independently of the active power exchanged with the grid, as well as a fast dynamic response. The designed equivalent control law determines, at each sampling period, the appropriate q-axis component of the modulated input current to be injected into the grid through the LC input filter. An integral term of the error is included in the expression of the sliding surface to increase the accuracy of the control method. A double space vector modulation method is used to synthesize the direction of the space vector of the input currents as required by the sliding-mode controller and the space vectors of the target output voltages. Simulation and experimental results are provided to show the effectiveness and evaluate the performance of the proposed control method.

• 융합정보논문지
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• 제12권5호
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• pp.256-270
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• 2022

본 연구에서는 품질경영요소(QM)가 카자흐스탄 제조기업의 경영성과(재무성과, 비재무성과)에 미치는 영향을 살펴보았다. 알마티지역 287개 제조기업을 대상으로 연구모형을 이용하여 10개의 가설을 설정·검증한 결과, 8개의 개설만이 지지되었다. 최고경영진 리더십은 재무성과에 긍정적인 영향을 미치는 중요한 요인으로 확인되었으며, 고객중심적 사고는 비재무적 성과에 가장 긍정적인 영향을 끼치는 요인으로 밝혀졌다. 임직원 참여와 품질정보요인도 경영성과에 긍정적인 영향을 미쳤으나, 영향력은 타 품질요인에 비하여 상대적으로 적은 것으로 나타났다. 공급자 관리요인은 경영성과에 유의한 영향을 미치지 않았으며, 관련된 2개의 가설도 지지되지 않았다. 이러한 분석결과는 대상기업들이 고품질의 완제품이 아닌 석유 및 원자재제조, 건설 등의 업체들로 구성된 데에 기인한 것으로 풀이된다.

• 한국표면공학회지
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• 제34권5호
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• pp.414-420
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• 2001

A 30-kV plasma immersion ion implantation setup (P $I^3$) has been equipped with a self-developed 6'-magnetron to perform hard coatings with enhanced adhesion by P $I^3$D(P $I^3$ assisted deposition) process. Using ICP source with immersed Ti antenna and reactive magnetron sputtering of Ti target in $N_2$/Ar ambient gas mixture, the TiN films were prepared on Si substrates at different pulse bias and ion-to-atom arrival ratio ( $J_{i}$ $J_{Me}$ ). Prior to TiN film formation the nitrogen implantation was performed followed by deposition of Ti buffer layer under A $r^{+}$ irradiation. Films grown at $J_{i}$ $J_{Me}$ =0.003 and $V_{pulse}$=-20kV showed columnar grain morphology and (200) preferred orientation while those prepared at $J_{i}$ $J_{Me}$ =0.08 and $V_{pulse}$=-5 kV had dense and eqiaxed structure with (111) and (220) main peaks. X-ray diffraction patterns revealed some amount of $Ti_{x}$ $N_{y}$ in the films. The maximum microhardness of $H_{v}$ =35 GN/ $M^2$ was at the pulse bias of -5 kV. The P $I^3$D technique was applied to enhance wear properties of commercial tools of HSS (SKH51) and WC-Co alloy (P30). The specimens were 25-kV PII nitrogen implanted to the dose 4.10$^{17}$ c $m^{-2}$ and then coated with 4-$\mu\textrm{m}$ TiN film on $Ti_{x}$ $N_{y}$ buffer layer. Wear resistance was compared by measuring weight loss under sliding test (6-mm $Al_2$ $O_3$ counter ball, 500-gf applied load). After 30000 cycles at 500 rpm the untreated P30 specimen lost 3.10$^{-4}$ g, and HSS specimens lost 9.10$^{-4}$ g after 40000 cycles while quite zero losses were demonstrated by TiN coated specimens.s.

• 한국벤처창업학회:학술대회논문집
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• 한국벤처창업학회 2021년도 춘계학술대회
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• pp.33-42
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• 2021

Based on the findings of Lee et al.(2020) and Lee & Oh(2021), this paper aims to fill the gap in our knowledge regarding the relationship between strategic choices and corporate growth by utilizing a novel dataset of 'Unicorn' and 'Hyper-growing' companies. Two previous studies provide coherent findings that the relationship between firms' strategies and their performance should be explored under a more comprehensive framework with consideration of both internal and external factors. Therefore, in this study, we apply a single conceptual framework to two different datasets, which considers the strategy factors as independent variables, and the industry(market) and the firm age as moderating variables. For our dependent variables, valuations for unicorn companies and revenue CAGR for hyper-growing companies are used after categorizing them into three uniform groups. The strategy variables include 'Generic (Cost-leadership, Differentiation, focus) strategies', 'Growth(Organic, M&A) strategies', 'Leading(Pioneer, Fast-follower) strategies', 'Target market(B2B, B2C, B2G, C2C) strategies', 'Global(Global, Local) strategies', 'Digital(Online, Offline) strategies.' For industry(market) factors, it consists of historical growth rate for industries and economic, demographic, and regulatory aspects of states and countries. To overcome the differences in their units, they are also uniformly categorized into multiple groups. Before we conduct a regression analysis, we analyze the industry distribution of the 'Unicorn' and the 'Hyper-growing' companies with descriptive statistics at the integrated and individual levels. Next, we employ hierarchical regression models on Study A('Unicorn' companies in 2019) and Study B('Hyper-growing' companies in 2019) under the same comprehensive framework. We then analyze the relationship between the 'strategy' and the 'performance' factors with two different approaches: 1) an integrated regression model with both the sample of Study A and B and 2) respective regression models on Study A and B. This empirical study aims to provide a complete understanding and a reference to which strategy factors should be considered to promote firms' scale-up and growth.

• 한국음향학회지
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• 제25권4호
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• pp.184-190
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• 2006

최근에 Lee 등은 1차원 수평배열 센서만을 사용하여 다중경로를 통해 들어오는 신호로부터 표적의 3차원 위치를 추정하였다. 그러나 이 기법에서 음속은 수심에 상관없이 일정하다고 가정하였기 때문에 음속이 수심에 따라 다양하게 변화하는 실제 해양환경에서는 그 추정 성능이 현저하게 저하된다. 따라서 본 논문에서는 비균일 음속 환경에 적합한 근거리 표적의 3차원 위치추정 기법을 제안한다. 제안한 기법에서는 선형의 음속구조를 가지는 근거리 다중경로 환경에서 음파전달 모델을 기반으로 한 위치추정함수를 구성하였으며 이로부터 표적의 방위각, 거리 및 깊이를 3차원 탐색을 통하여 추정하였다. 선형 음속구조 및 실제 환경과 유사한 비선형 음속구조를 적용하여 제안한 기법의 성능을 기존의 기법과 비교, 분석하였으며 기존의 기법에 비해 거리 추정 오차는 최대 100m, 깊이 추정 오차는 50m정도 감소됨을 확인하였다.

• 수산해양기술연구
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• 제60권3호
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• pp.244-257
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• 2024

Considering the negative impact of IUU fishing on fishery resources and fishery management, a revised approach for estimating risks of the ecosystem-based fisheries assessment (EBFA) of Zhang et al. (2011) was developed that incorporates three components of the IUU (illegal, unreported and unregulated) fishing as penalties. In this study, we introduced ways to develop indicators of IUU fishing suitable for the Korean fishery and apply them to ecosystem-based resource assessment. The indicator for the illegal fishing component was set as the fishing without licenses or permits, and that for the unreported fishing component was set as unreported fishing activities. Indicators for the unregulated fishing component were set as fishing operated by illegal fishing gear, illegal fish capture, fishing operations in prohibited fishing area, and fishing with restrict permits. IUU fishing significantly impacts the stock of target species. Therefore, in this study, the influence of IUU fishing is included in the Species Risk Index (SRI) at the species level, and weights are assigned based on the ratio of the stock, as $SRI={{\sum\limits_j}{\lambda}_j{\cdot}ORI/{\sum\limits_j}{\lambda}_j}+P_f(B_i/B)$. The revised ecosystem-based fisheries assessment method, which considers the impact of IUU fishing, was applied to major fisheries on the south coast of Korea. It is necessary to reduce the non-reporting rate through the expansion of the TAC system and improve the accuracy of statistical compilation. To this end, the electronic fishing reporting system, which is being implemented on all vessels in Korean distant water fishing vessels, should be introduced to the coastal and offshore fisheries as well.

• 대한수의학회지
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• 제64권3호
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• pp.19.1-19.8
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• 2024

Blue light in the visible spectrum naturally fights bacteria and effectively deactivates various Gram-positive and Gram-negative bacteria and fungi using photodynamic processes. It works against drug-resistant strains within these species and is gentler on mammalian cells than ultraviolet rays or chemicals. This study evaluated blue light as an affordable way to sanitize surfaces in poultry settings, such as eggs and litter. The study used an light-emitting diode array to remove harmful Escherichia coli and Staphylococcus aureus from these items and observed how blue light affected their survival rates. Blue light (455 nm) at 30 mW/cm2 for one hour decreased the survival of S. aureus and E. coli on solid agar plates to 29.88% and 21.04%, respectively, compared to non-irradiated cultures. Similarly, on untreated surfaces (such as plastic used for feeding and drinking), the survival rates dropped to 25.8% and 15.6%, respectively. The survival percentages on treated eggs were 50% (S. aureus) and 36.47% (E. coli) and 49% (S. aureus) and 48.2% (E. coli) on treated litter. Hence, blue light technology offers a promising alternative to traditional antimicrobial methods by leveraging specific wavelengths to target microbial cells. This approach can significantly reduce the microbial load in poultry environments, enhancing food safety and animal health. This paper reports the first use of blue light as an antibacterial within poultry research in Iraq, offering a fresh approach to disinfection in this field.

• 마케팅과학연구
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• 제20권2호
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• pp.135-148
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• 2010

阿拉伯人联合抵制丹麦产品, 澳大利亚人联合抵制法国产品, 而中国人厌恶日本产品, 这些是国家间的敌对行为影响消费行为的案例. 敌意文献中已考查过消费者对其他国家敌对行为的反应, 以及这种敌意如何影响消费者对敌对国家产品的态度和倾向. 例如, 中国消费者不愿购买日本产品, 是由于日本人在第二次世界大战中的暴行, 以及不平等的经济往来(Klein, Ettenson and Morris 1998). 然而在市场营销文献中, 却没有考查过那些对他国实施敌对行为的国家消费者的反应, 这些敌对行为是否会影响他们购买受害国产品的态度. 社会心理学文献认为, 消费者面对这样的敌对行为时, 会产生一种集体犯罪感. 集体犯罪感源于当组织成员认为组织要对伤害其他组织的行为负责时所产生的痛苦感(Branscombe, Slugoski, and Kappenn 2004). 案例包括美国人由于美军在Abu Ghraib监狱的暴行而产生犯罪感(Iyer, Schamder and Lickel 2007), 荷兰由于过去对印度尼西亚的占领而产生犯罪感(Doosje et al. 1998). 本研究的主要目的是考查当国家成员对他国有敌对行为时消费者的感知, 这种感知是否会影响他们对敌对国家产品的态度. 更准确的说, 本研究的目标之一是考查集体犯罪感的感知前提, 以及当国家成员对他国有敌对行为时, 人们的情绪反应. 另一个目标是考查集体犯罪感如何影响消费者对敌对国产品的感知和倾向. 如果集体犯罪感能起到明显的预言作用, 敌对国双方的公司可能会从这类不幸的事件中受益. 本研究利用了由Klein, Ettenson and Morris (1998)提出并经Klein (2002)发展的敌意模式. Klein发现美国消费者对日本人怀有敌意, 起因是二战期间的事件(如日军偷袭珍珠港)和近年来日本的经济威胁. 因此本研究认为, 二战间的事件(如广岛长崎的原子弹爆炸)可能导致美国消费者的集体犯罪感. 曾有过一系列的三个假设, 第一个假设关于集体犯罪感的前提. 之前有研究认为当消费者感知到侵害造成的非法伤害, 并且认为侵犯者来自的国家应为此负责, 集体犯罪感就产生了(Wohl, Branscombe, and Klar 2006). 因此提出下列假设: 假设1a: 感知到的伤害非法性越高, 集体犯罪感越强烈. 假设1b: 责任越大, 集体犯罪感也肯定越强烈. 第二个和第三个假设关于集体犯罪感对倾向日本产品的影响. Klein (2002)发现对日本的敌意越强, 相比较韩国产品对日本产品的倾向越小, 但相比较美国产品对日本产品的倾向并未变小. 这些结果说明集体犯罪感存在时, 消费者在购买日本产品和韩国产品时会更倾向于前者, 但在购买日本产品和美国产品时并未受影响. 假设2: 集体犯罪感与购买日本产品的倾向大于韩国产品有关, 但与购买日本产品的倾向大于美国产品无关. 假设3: 集体犯罪感与购买日本产品的倾向大于韩国产品有关, 并且对产品的判断和敌意保持不变. 有过一个实验测试这个假设. 使被调查者面临发生在二战中的敌对事件, 从而产生非法伤害和责任. 该实验由一家美国的消费者调查小组收集数据, 将调查对象随机分配到低等级责任和违法情况(n=259)或高等级责任和违法情况(n=268). 测试假设关系时, 运用到潜在变量结构方程模式(LVSEM). 第一个假设得到了支持, 美国人因二战中对日本人的伤害而产生的伤害非法性和责任都对集体犯罪感有积极影响. 第二个假设也得到了支持, 集体犯罪感与购买日本产品的倾向大于韩国产品有关, 但与购买日本产品的倾向大于美国产品无关. 最后, 第三个假设也得到了支持, 集体犯罪感与购买日本产品的倾向大于韩国产品有关, 同时还影响人们对日本产品的判断和敌意. 由这些研究的结果可得出结论. 第一, 伤害的非法性和责任是集体犯罪感的前提. 第二, 当消费者面临来自敌对行为目标国家的产品和其他外国产品之间的选择时, 会受到集体犯罪感的影响. 但当他们面临来自敌对行为目标国家的产品和本国产品时, 不受集体犯罪感的影响. 这一结果意味着当竞争对手来自国外时, 利用集体犯罪感对那些受到敌对行为的国家的公司是可行的, 但当竞争对手来自国内时则不可行.