• Bulletin of the Korean Chemical Society
• /
• v.29 no.4
• /
• pp.731-735
• /
• 2008

The fluid ensemble in the liquid lens, which is composed of electrolyte and silicone oil, is the key material system to vary the focal length processing of the electrochemical desorption. In order to characterize the capability of the liquid lens according to response time and optical range, we prepared a fluid ensemble comprising the electrolyte and oil. To elucidate the physical mechanism of the effective response time, we examined the viscosity dependency while satisfying the requirements for the density and refractive index of the electrolyte and oil, respectively. The characterization results indicated that the response time (up and down) is influenced by the viscosity of the electrolyte and oil. On this basis, we prepared a fluid ensemble capable of reversibly adjusting for the focal length of the liquid lens, as well as the response time. The ensemble is applicable to various systems such as micro-lens and optical sensors.

• Current Optics and Photonics
• /
• v.4 no.5
• /
• pp.428-433
• /
• 2020

Recently, the on-chip autofocus (AF) function has become essential to the CMOS image sensor. An auto-focus usually operates using phase detection of the photocurrent difference from a pair of AF pixels that have focused or defocused. However, the phase-detection method requires a pair of AF pixels for comparison of readout. Therefore, the pixel variation may reduce AF performance. In this paper, we propose a color-selective AF pixel with a plasmonic nanostructure in a 0.9 μ㎡ pixel. The suggested AF pixel requires one pixel for AF function. The plasmonic nanostructure uses metal-insulator-metal (MIM) stack arrays instead of a color filter (CF). The color filters are formed at the subwavelength, and they transmit the specific wavelength of light according to the stack period and incident angles. For the optical analysis of the pixel, a finite-difference time-domain (FDTD) simulation was conducted. The analysis showed that the MIM stack arrays in the pixels perform as an AF pixel. As the primary metric of AF performance, the resulting AF contrasts are 1.8 for the red pixels, 1.6 for green, and 1.5 blue. Based on the simulation results, we confirmed the autofocusing performance of the MIM stack arrays.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.11
• /
• pp.251-257
• /
• 2020

The study investigates the role of commodity prices and tax purpose recognition on bitcoin prices. Since the introduction of bitcoin in 2008, emphasis has focused on economists, policy-makers and analysts drastically increasing bitcoin's accessibility and commodity values (Dumitrescu & Firică, 2014). This study employs GARCH and EGARCH from ARCH/GARCH family on daily nature data. We measure the volatile behavior of bitcoin by employing auto-regressive conditional heteroscedasticity model with the aim to explore the relationship between major commodities and bitcoin volatility. We focus on major commodities like gold, silver, platinum, and crude oil to be regressed with bitcoin. The daily prices of commodities were retrieved from www.investing.com and bitcoin prices from www.coindesk.com for the period from 29April 2013 to 16 October 2018. Results confirmed the currency's long-term volatile behavior, which is due to its composition and market dynamics, whereas the existence of asymmetric information effect is not confirmed. Tax recognition by other countries may in future help in controlling the volatility as bitcoin is not a country-specific security. But, only silver impacts on volatility in comparison to oil prices and platinum, which is due to its similar features with gold. Eventually, bitcoin can be used for risk diversification and money making.

• The Journal of Fisheries Business Administration
• /
• v.46 no.3
• /
• pp.31-49
• /
• 2015

This study examines whether or not the South Korean major fishery product import markets; Frozen Pollock, Frozen Long Arm Octopus, and Frozen Hairtail are integrated. We are utilizing the Multivariate and Bivariate Johansen Co-integration test to see if the law of one price(LOP) holds in each market or not. The empirical results show that even though import prices from different countries affect each other in each South Korean major fishery product import market, there is no evidence of LOP in any fishery product import market, which means that none of the markets are integrated. Based on these results, we could expect that the three major fishery product import markets show monopolistic competition among import countries. we would also see whether or not any country plays the role of a price leader in any of the markets. Based on weak exogeneity test results, we might expect that the United States and Malaysia are price leaders in the South Korean Frozen Pollock Import Market and Frozen Long Arm Octopus Import Market, respectively; however, we need to study more on this in the future.

• Journal of the Korea Safety Management & Science
• /
• v.13 no.1
• /
• pp.143-150
• /
• 2011

과거의 기업은 단순 생산과 관리만으로 기업을 유지시켜 왔다. 그러나 오늘날 제품 소비자들은 다양하고 복잡한 요구를 하고 있고 기업은 소비자들의 욕구를 충족시키지 못하면 존속할 수가 없다. 따라서 기업은 다양한 소비자의 요구에 대한 사회적, 경제적 환경변화에 대응 할 수 있는 최적의 기본 방침을 수립하고 그것을 실천하는 경영전략 수립이 필요하다. 경영전략 수립은 기업경영성과에 영향을 주는 가장 중요한 요인이라 할 수 있는데, 경영전략 수립과 기업경영성과라는 두 요인 사이에는 또 다른 복잡한 관리체계가 작용한다. 즉 생산시스템과 전사적 품질경영활동, 구성원들에 대한 보상, 그리고 조직구성원간의 관계 등이 영향을 미치는 것이다. 본 연구는 기업의 경영전략과 관리체계인 생산시스템, TQM 활동과 종업원에 대한 보상이 경영성과에 어떠한 영향이 있는지를 파악하고 이것을 기반으로 실증적 자료를 수집하여 분석 검증함으로써 기업발전의 토대로 삼고자 한다. 자료 분석을 위하여 SPSS 통계 패키지를 이용하였고, 각 연구 가설과 연구 모형은 구조방정식을 이용하여 검증하였다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.7
• /
• pp.1121-1127
• /
• 2016

In this paper, modeling of overcurrent relay(OCR) to protect domestic AC electric railway Auto Transformer(AT) feeding system and operation characteristic analysis on overload condition are described. The target system of this paper is actual site where overload trip of circuit breaker occurs frequently. Because this AT feeding system is made of parallel single track which had a load(electric train) respectively, and is connected with only T phase of Scott Transformer. In addition, this system has been feeding 66kV voltage by KEPCO, not 154kV. We focus on protective coordination of Scott Transformer primary side and secondary side OCR for Korea single track AC electrical railway system in operation currently. We modeled single track AT feeding system and OCR. Also we performed faults and overload analysis for verification of OCR's setting values and system modeling. To analyze above mentioned research, we used PSCAD/EMTDC software tool.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.57.2-57.2
• /
• 2018

In astronomical observation, sequential device control and real-time data processing are important to maximize observing efficiency. We have developed series of automatic observing software (KAOS, KHU Automatic Observing Software), e.g. KAOS30 for the 30 inch telescope in the McDonald Observatory and KAOS76 for the 76 cm telescope in the KHAO. The series consist of four packages: the DAP (Data Acquisition Package) for CCD Camera control, the TCP (Telescope Control Package) for telescope control, the AFP (Auto Focus Package) for focusing, and the SMP (Script Mode Package) for automation of sequences. In this poster, we introduce KAOS10 which is being developed for controlling a small telescope such as aperture size of 10 cm. The hardware components are the QHY8pro CCD, the QHY5-II CMOS, the iOptron CEM 25 mount, and the Stellarvue SV102ED telescope. The devices are controlled on ASCOM Platform. In addition to the previous packages (DAP, SMP, TCP), KAOS10 has QLP (Quick Look Package) and astrometry function in the TCP. QHY8pro CCD has RGB Bayer matrix and the QLP transforms RGB images into BVR images in real-time. The TCP includes astrometry function which adjusts the telescope position by comparing the image with a star catalog. In the future, We expect KAOS10 be used on the research of transient objects such as a variable star.

• International journal of advanced smart convergence
• /
• v.10 no.3
• /
• pp.66-71
• /
• 2021

Recent healthcare environments have characteristics of expanding the scope of healthcare-impacting healthcare, complexity resulting from diversification of components, and accelerating the pace of change. Drugs are used for the prevention, mitigation, and treatment of diseases, so they can inevitably cause harm, while they have efficacy and effectiveness, which are key elements of health recovery. Therefore, many countries regulate permits for safe and effective medicines, and also designate essential drugs directly related to life as pay targets and guarantee health insurance. Especially Pharmacist relying on manpower for composition medicine is liable for mal-manufacture due to combination of toxic medical substances or other chemical usage. In this paper, we focus on using Kiosk and Optical Character Recognition (OCR) for automated pharmacy to level up medical service and create labor friendly environment for pharmacist themselves through maintenance of prescription data and automated manufacturing solution. Presentation of drug substances and precautions will lead to efficient drug prescription and prevent misuse of information while auto manufacturing system efficiently maintain labor force and raise patient satisfaction level by reduction of waiting time.

• Korean Journal of Optics and Photonics
• /
• v.31 no.6
• /
• pp.314-320
• /
• 2020

The optics used in an infrared imaging system has a strong refractive-index change according to temperature, so an autofocus control function is essential for a military infrared imaging system with a wide operating-temperature range. In this study, we design a triple-magnification infrared imaging system, and to compensate for the change in refractive index according to temperature we measure the change in the lens focus according to temperature. The autofocus control function was implemented by using the measured movement amount, and we could obtain an image with satisfactory resolution performance over a wide range of operating temperatures.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.1
• /
• pp.93-100
• /
• 2008

The parameters of lens such as focal length, focus, and aperture stop changes while shooting the scenes with zoom lens. Especially, zooming action dramatically changes the geometry of lens system that causes significant change of lens model. We investigated how the lens model changes while zooming in general shooting condition. Each parameters of lens model was estimated and checked whether they can be modeled well in the condition of auto-controlling focus, aperture and vibration reduction. In order to do this, calibration images were taken, modeled in different fecal length setting. And changing patterns of models were inspected to find out if there is some elements that have some particular pattern in changing with respect to focal length. The result showed us that although we didn't control the focus and aperture setting, there's specific changing patterns in radial and do-centering distortion. Especially, the strong linear correlation was found between coefficient of $r^2$ and focal length. It is expected that many parts of distortion can be eliminated without additional self calibration even if zoom operation is done when shooting the scenes if we know its fecal length and model of this coefficient.