• Atmosphere
• /
• v.21 no.4
• /
• pp.447-454
• /
• 2011

As dust storms originated in Neimongu Plateau and Manchuria became more frequent in Korea, there was a growing need for Asian Dust (Hwangsa) monitoring stations in North Korea, which is a pathway of Asian Dust to South Korea. The South Korean and the North Korean Governments agreed to build the Automatic Weather System and the PM10 measurement instruments in the Gaeseong Industrial Zone and the Keumgangsan Tourist Region, North Korea in 2007. PM10 mass concentration data in the Keumgangsan Tourist Region could be collected only during the period from September 2007 to May 2008. In this study, daily, monthly and diurnal variations of PM10 mass concentration of the Keumgangsan are analyzed and compared with those of Sokcho and Gwangdeoksan. Three sites show similar variations in daily and monthly means. Correlation coefficients (r) between Sokcho and Keumgangsan, and between Gwangdeoksan and Keumgangsan are 0.89 and 0.67, respectively. But diurnal variation at Keumgangsan has a distinct feature compared to the other sites. Diurnal PM10 variation shows two peaks around 8 AM and 4-5 PM and very low at night. The difference between the daily maximum and minimum is $20{\sim}60{\mu}g\;m^{-3}$ during September to November 2007. Temperature, relative humidity and wind speed from the Keumgangsan AWS data were compared with those from the Changjon station, and showed good correlation each other except wind speed.

• Korean Journal of Community Nutrition
• /
• v.5 no.1
• /
• pp.109-119
• /
• 2000

The purpose of this study was to measure serum lipids concentrations by gender and age, and to investigated the relation of serum lipids levels to cigarette smoking alcohol intake exercise and menopausal status in Korean adults. The subjects consisted of 463 healthy adult(29- men and 173 women) volunteers who were visiting the health Promotion Center in the Asan Medical Center from July 1, 1994 to July 22, 1994 Subjects were ambulatory free-living people and aged 20- 80 years, Anthropometric measurement was performed and serum triglyceride(TG), HDL-cholesterol and total cholesterol(TChol) concentrations were measure by automatic system(Hitachi 736-40). Data on life styles were obtained using structured questionnaires issued by a trained interviewer, All data were statistically analyzed by PC-SAS(Version 6.04) Serum concentrations of triglyceride and total cholesterol was higher(p<0.05) in men than in women, and serum HDL-cholesterol was lower(p<0.05) in men than in women. The prevalence of hyperlipidemia(TG>170 mg/dL and TChol>220 mg /dL) was 12.5% in men and 4.1% in women. The levels of serum triglyceride, total cholesterol and BMI increased with age in women. The distribution curves of serum triglyceride, total cholesterol and LDL-cholesterol of women were located in lower increased more rapidly with aging than in men, The distribution curves of BMI of women increased with aging after the thirties, The BMI of women was located in higher levels than of men in their sixties. The serum concentration of triglyceride and total cholesterol of male current-smokers and non- smokers were significantly(p<0.05) higher than those of ex-smokers. The concentrations triglyceride the male current0drinkers were higher(p<0.05) than those of male non-drinkers. In non-smokers and non- drinkers, serum TG concentration were lower (p<0.05) than those of current-smokers and current-drinkers. In exercisers, the serum triglyceride concentration was significantly(p<0.05) lower than in non- exercisers. In postmenopausal woman BMI and serum concentrations of TChol, TG and LDL-Chol were significantly by age and gender and smoking alcohol drinking, exercise and menopausal staus might be a better indicator to predict serum lipids in both genders.

• Journal of Biomedical Engineering Research
• /
• v.36 no.5
• /
• pp.204-210
• /
• 2015

Although many studies have analyzed the relationship between electrodermal activity (EDA) and sleep stages, a practical method for detecting sleep stage using EDA has not been suggested. The aim of this study was to develop an algorithm for real-time automatic detection of deep sleep using the EDA signal. Simultaneously with overnight polysomnography (PSG), continuous measurement of skin conductance on the fingers was performed for ten subjects. The morphometric characteristics in the fluctuations of EDA signal were employed to establish the quantitative criteria for determining deep sleep. The 30-sec epoch-by-epoch comparison between the deep sleep detected by our method and that reported from PSG exhibited an average sensitivity of 74.6%, an average specificity of 98.0%, and an average accuracy of 96.1%. This study may address the growing need for a reliable and simple measure for identifying sleep stage without a PSG.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.1141-1144
• /
• 2005

In this paper, we propose an automatic displacement system for testing stability of structure. Photogrammetry is a method which can measure accurate 3D data from 2D images taken from different locations and which is suitable for analyzing and measuring the displacement of structure. This paper consists of camera calibration, feature extraction using coded target & retro-reflective circle, 3D reconstruction and analyzing accuracy. Multi-view camera which is used for measuring displacement of structure is placed with different location respectively. Camera calibration calculates trifocal tensor from corresponding points in images, from which Euclidean camera is calculated. Especially, in a step of feature extraction, we utilize sub-pixel method and pattern recognition in order to measure the accurate 3D locations. Scale bar is used as reference to measure. the accurate value of world coordinate..

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.8
• /
• pp.1363-1369
• /
• 2008

As game and character animation industries are growing, techniques for reproducing realistic character behaviors have been required in various fields. Therefore, intensive researches have been performed in order to find various methods for realistic character animation. The most common approaches to character animation involves tedious user input method, simulation with physical laws based on dynamics, and measurement of actors' behaviors with input devices such as motion capture system. These approaches have their own advantages, but they all have common disadvantage in character control. In order to provide users with convenient control, the realistic animation must be generated with high-level parameters, and the modification should also be made with high-level parameters. In this paper we propose techniques for developing an automated character animation tool which operates with high-level parameters, and introduce techniques for developing actual games by utilizing this tool.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.82-82
• /
• 2019

최근 사물인터넷 등의 IT기술의 발전과 함께 수리 계측 분야에서도 자동 유속 및 유량 측정장비들에 대한 연구와 적용이 활발하게 진행되고 있다. 하지만 최근 개발된 자동 유속 측정 장비들은 설치가 어려울 뿐만 아니라 비용이 많이 들기 때문에 쉽게 적용하기가 어려워 극히 소수의 지점에서만 운영 중에 있으며 전국 2만2,823개소에 달하는 소하천에 적용하기에는 무리가 있다. 이와 같은 문제점들을 해결하기 위해 보다 간편하고 경제적인 유속 측정 방법으로 주목을 받고 있는 방법이 표면영상유속계이다. 표면영상유속계는 일반 동영상 촬영 장비와 분석 소프트웨어만 있으면 유속을 측정할 수 있기 때문에 매우 경제적이고, 비접촉식으로 유속을 측정하기 때문에 흐름에 방해를 주지 않을뿐만 아니라 홍수 시 유속 측정의 위험성을 최소화 할 수 있다는 장점이 있어, 유량과 수위가 급격하게 변하는 국내 소하천의 유량측정에 적절하게 대응할 수 있다는 장점이 있다. 이에 본 연구에서는 기존의 표면영상유속계를 실시간 자동유량계측이 가능하도록 시스템화 하여 개선하였다. CCTV 기반의 실시간 소하천 자동유량계측 시스템의 구성은 CCTV, 초음파수위계, 현장제어함체 및 조명으로 구성되어 있고, 현장제어함체에는 CCTV 영상분석 S/W가 설치되어 있으며, 실시간으로 산정한 유속자료와 초음파수위계로 측정한 수위자료를 이용하여 유량을 자동으로 산정하도록 개발하였다. 또한 울주군에 위치한 중선필천에 설치하여 적용성 여부 및 현장검증을 실시하였으며, 2018년 홍수사상에 대한 유량계측을 실시한 결과 표면영상만으로 소하천의 유속을 매우 짧은 시간에 계측할 수 있어 소하천의 급격한 유량 변화를 매우 안정적으로 계측하여 온전한 홍수 사상을 확보 할 수 있었다. 또한, 현장 계측 인력 없이도 CCTV 영상으로 현장상황을 파악할 수 있어 홍수대응 지원도 가능한 장점이 있음을 확인하였다.

• International Journal of Computer Science & Network Security
• /
• v.21 no.4
• /
• pp.255-263
• /
• 2021

Smart grid is a fully-automated, bi-directional, power transmission network based on the physical grid system, which combines sensor measurement, computer, information communication, and automatic control technology. Blockchain technology, with its security features, can be integrated with Smart Grids to provide secure and efficient power management and transmission. This paper dicusses the deployment of Blockchain technology in Smart Grid. It presents application areas and protocols in which blockchain can be applied to in securing smart grid. One application of each area is explored in detail, such as efficient peer-to-peer transaction, lower platform costs, faster processes, greater flexibility in power generation to transmission, distribution and power consumption in different energy storage systems, current barriers obstructing the implementation of blockchain applications with some level of maturity in financial services but concepts only in energy and other sectors. Wide range of energy applications suggesting a suitable blockchain architecture in smart grid operations, a sample block structure and the potential blockchain technicalities employed in it. Also, added with efficient data aggregation schemes based on the blockchain technology to overcome the challenges related to privacy and security in the smart grid. Later on, consensus algorithms and protocols are discussed. Monitoring of the usage and statistics of energy distribution systems that can also be used to remotely control energy flow to a particular area. Further, the discussion on the blockchain-based frameworks that helps in the diagnosis and maintenance of smart grid equipment. We have also discussed several commercial implementations of blockchain in the smart grid. Finally, various challenges have been discussed for integrating these technologies. Overall, it can be said at the present point in time that blockchain technology certainly shows a lot of potentials from a customer perspective too and should be further developed by market participants. The approaches seen thus far may have a disruptive effect in the future and might require additional regulatory intervention in an already tightly regulated energy market. If blockchains are to deliver benefits for consumers (whether as consumers or prosumers of energy), a strong focus on consumer issues will be needed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.1
• /
• pp.67-74
• /
• 2022

To analyze the motion of aircraft through computing the dynamics equations, true airspeed is essential for obtaining aerodynamic loads. Although the airspeed is measured by on-board instruments such as pitot tubes, measurement data are difficult to obtain for commercial flights because they include sensitive data about the airline operations. One of the commonly available trajectory data, Automatic Dependent Surveillance-Broadcast data, provide aircraft's speed in the form of ground speed. The ground speed is a vector sum of the local wind velocity and the true airspeed. This paper present a method to estimate true airspeed by combining the trajectory, meteorological, and topology data available to the public. To integrate each data, we first matched the coordinate system and then unified the altitude reference to the mean sea level. We calculated the wind vector for all trajectory points by interpolating from the lower resolution grid of the meteorological data. Finally, we calculate the true airspeed from the ground speed and the wind vector. These processes were applied to several sample trajectories with corresponding meteorological data and the topology data, and the estimated true airspeeds are presented.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.3
• /
• pp.266-274
• /
• 2023

Recently, sterilization technology has received increasing interest due to the COVID-19 pandemic and required safety precautions. Particularly, sterilization devices using near ultraviolet (UV) with a 405 nm wavelength are also drawing attention. It has a UV-C wavelength and other sterilization effects. Its blue-colored light on the boundary between UV and visible light is used as a light-emitting diode (LED) lamp for 405 nm sterilization, owing to its longer wavelengths than UV rays. However, the 405 nm wavelength contains blue light that can damage the eyes and skin during prolonged exposures and affect the emotional and biological parts of the body. Currently, 405 nm sterilization LED light registers are circulating in the market. However, they have not undergone safety tests for blue-light hazards. Thus, with the active distribution of sterilization LED lights, solid safety standards and management systems are essential to protect users from blue-light hazards. Accordingly, in this study, we conducted spectral radiance and spectral radiative luminance tests on 405 nm sterilization LED registers available in the market by the measurement criteria of IEC 62471. Safety standards must be established to secure users' safety against blue light hazards at a time when 405nm sterilization LED lights are actively distributed due to COVID-19.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.2
• /
• pp.148-157
• /
• 2022

Research on hydrogen storage is active to properly deal with hydrogen, which is considered a next-generation energy medium. In particular, research on metal hydride with excellent safety and energy efficiency has attracted attention, and among them, magnesium-based hydrogen storage alloys have been studied for a long time due to their high storage density, low cost, and abundance. However, Mg-based alloys require high temperature conditions due to strong binding enthalpy, and have many difficulties due to slow hydrogenation kinetics and reduction in hydrogen storage capacity due to oxidation, and various strategies have been proposed for this. This research manufactured Mg₂Ni to improve hydrogenation kinetics and synthesize about 5, 10, 20 wt% of CaF₂ as a catalyst for controlling oxidation. Mg₂NiHx-CaF₂ produced by hydrogen induced mechanical alloying analyzed hydrogenation kinetics through an automatic PCT measurement system under conditions of 423 K, 523 K, and 623 K. In addition, material life cycle assessment was conducted through Gabi software and CML 2001 and Eco-Indicator 99' methodology, and the environmental impact characteristics of the manufacturing process of the composites were analyzed. In conclusion, it was found that the effects of resource depletion (ARD) and fossil fuels had a higher burden than other impact categories.