• Journal of the Korean Society of Safety
• /
• v.8 no.2
• /
• pp.94-98
• /
• 1993

This study discusses a possible ergonomics application for adult wheelchair design in consideration of anthropometry, physical load, control ability, posture, subjective analysis, security and so on. Korean normal adults who ever used wheelchairs are examined. And anthropometric data and basic data to make standard wheelchair are provided.

• Journal of Sensor Science and Technology
• /
• v.1 no.1
• /
• pp.77-83
• /
• 1992

A primary standard of ac current at low frequency is derived from the standard of dc current by ac-dc transfer instrument. A set of 15 thermal current converters(TCCs) have been constructed as the primary current standards from 5 mA to 20 A at the frequency range of 10 Hz to 100 kHz. It is evaluated that the uncertainties for the maintenance and dissemination of ac current standard are less than 52 ppm up to 20 mA and 20 kHz, 60 ppm up to 100 mA and 20 kHz, and rising to 200 ppm at higher currents and frequencies.

• Journal of the Korean Vacuum Society
• /
• v.15 no.1
• /
• pp.1-13
• /
• 2006

Vacuum laboratory in Korea Research Institute of Standards and Science (KRISS) was opened in 1983 for establishing and disseminating vacuum standard in Korea. The major three systems such as the ultrasonic interferometer manometer (UIM), the static expansion system (SES) and the dynamic expansion system (DES) with orifice and porous plug conductance are developed. In this study, the standard systems from low to ultra-high vacuum, uncertainty analysis by ISO regulation, and key and bilateral comparison results will be described.

• Analytical Science and Technology
• /
• v.18 no.1
• /
• pp.74-84
• /
• 2005

Understandings of adsorption characteristic of interface are very important in several advanced materials processes, related to NT and BT technology. Volumetric gas adsorption method, suitable for absolute measurements, is regarded as the standardized measurement technique for specific surface area. In order to verify the reliability of commercial equipments, certified reference materials (called CRM) of specific surface area are developed and evaluated its uncertainty factors by standard equipment which has traceability to SI units. Specific surface areas of developed materials are $10.72{\pm}0.46m^2g^{-1}$ for silicon nitride powders and $149.50{\pm}3.44m^2g^{-1}$ for alumina. These disseminations of CRMs would result in improved reliability chains in industrial processes, and lead eventually to contribution to productivity improvement, quality management, safety evaluation, and possibly to new material development.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.3
• /
• pp.54-62
• /
• 1990

The thermodiluton is a standard method to measure cardiac output in clinical medicine. However it has many disadvantages such as expensive instrument and measurement, limited number of measurement, pain, safety problem, and side-effect due to insertion of catheter into heart. Electrical Impedance Cardiography has no such disadvantages and that it can continuously monitor stroke volume, contractility of cardiac muscle, and systolic time interval (STI) as well as cardiac output. While this impedance technique has been widely used and vigorously studied adroad, it is not introduced yet in Korea. Thus an Impedance Cardiograph has been developed in order to introduce this new technique. Its accuracy also has been verified by simultaneous measurement of cardiac output with the thermodilution technique. Finally changes of cardiac function during exercise were also measured.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.68-68
• /
• 2017

농작업 시에 가장 빈번하게 일어나는 위험한 농기계 관련 사고는 전도사고로 트랙터의 전복이 꼽히고 있다. 따라서 트랙터의 전복을 유발하는 주원인인 무게중심의 측정이 중요시 되고 있다. 지금까지 사용해 왔던 북미와 유럽, 일본 등의 선진 농기계 업체들이 사용하고 있는 트랙터 무게중심 측정방법(ISO 789-6 : OECD code2, 작도법)은 정밀성과 신뢰성이 다소 결여되어 이를 정확히 측정하기 위한 새로운 방법 및 알고리즘의 개발이 시급한 상황이다. 따라서 본 연구에서는 트랙터 무게 중심을 보다 정확히 측정할 수 있는 방법을 개발하고 이를 ISO에 NP(New Proposal)제안 과정을 거쳐 ISO 개정을 위한 기초연구로 수행되었다. 트랙터 무게중심 측정을 위한 ISO 789-6의 경우 작도법으로 시험하도록 되어 있으나, 본 연구에서는 무게중심을 계산할 수 있는 프로그램을 개발하고, 극좌표계산방식으로 측정된 값을 프로그램에 직접 입력하는 방법을 개발하여 신뢰성과 정밀성을 높일 수 있도록 하였다. 프로그램의 개발은 ISO(OECD) 방법에 대해 계산식을 개발하고 4개의 좌표가 교차하는 좌표와, 트랙터 후방을 들어 올렸을 때의 끝점 좌표, 전방을 들어 올렸을 때의 끝점 좌표 등을 구하는 자동 알고리즘을 개발하고, 중심 위치는 시험방법 및 트랙터의 제원에 따른 치수와 중량 데이터를 측정하여 입력하면 자동으로 계산이 되도록 하였다. 본 연구에서 개발한 방법과 기존 ISO 789-6(작도법)을 비교한 결과 보다 신뢰성 있는 결과를 얻을 수 있었으며, 이를 ISO에 NP제안을 위한 합리적인 시험방법임을 알 수 있었다. 개정작업이 완료될 시에 이 방법을 농기계 업체에 보급함으로써 보다 안전한 농기계 설계 및 제작에 기여하고 농민의 안전사고 예방에 기여할 수 있을 것이다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.3
• /
• pp.405-412
• /
• 2020

The thermistor mount is used for precise RF power measurement because the calibration factor is constant according to the change of power. The calibration factor of the standard mount can be measured with an uncertainty less than 0.5 % from the 10 MHz to 1 GHz by direct comparison with the transfer standard using the DC substitution method. Recently, as the supply of precision power meter based on DC substitution method allows simple and fast measurement, a simple direct comparison measurement system with the same level uncertainty was designed and the minimum required specifications of components through analysis of mismatch error was proposed. The uncertainty was evaluated for system validation, and the results show that uncertainties have been well maintained within 0.5 % in the measurement frequencies.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.76-76
• /
• 2013

Scanning Tunneling Microscopy는 개인용컴퓨터가 보급되고, 저잡음 아날로그 칩들을 구할 수 있으며, 압전세라믹 기술이 발달하기 시작한 1981년 스위스 IBM Zurich 연구소에서 H. Rohrer와 G. Binnig 박사에 의하여 발명되었다. 이 발명 7~8년 이전 미국 표준연구원의 R. Young 박사도 비슷한 시도를 하였지만, 이 때는 제어할 수 있는 컴퓨터가 없었고, 조절 회로의 잡음 레벨도 컸으며, 역학적 진동도 커서 목적을 달성할 수 없었다. STM의 발명 후 32년이 지난 지금, 조절용 컴퓨터의 발전은 물론, 조절용 역되먹임 회로 또한 digital signal processor나 FPGA를 사용하는 형태로 변화하여 전기적 잡음도 현저히 감소하였다 [1,2]. 동시에 측정 에너지 해상도를 개선하기 위하여 세계적으로 여러 그룹이 장치를 1 K 이하에서 작동할 수 있게 제작하였고, 0.3 K에서 작동하는 상업용 제품도 등장하였다. 이 결과 에너지 해상도는 30 meV 에서 2~3 ${\mu}eV$ 감소하였고, 온도변화에 따른 측정 위치의 변화도 피할 수 있게 되었다. 터널링 검침의 화학적 성분을 흡착과 같은 방법으로 조절하여, 공간 해상도는 물론 에너지 해상도도 더욱 줄일 수 있게 되었고, 스핀에 민감한 터널링 제어도 가능하게 되었다. 이제는 금속, 반도체, 초전도체는 물론 분자, 거대분자, 나노 크기의 양자점등도 측정이 가능하게 되었다. 분자진동 측정이 가능하며, 분자의 성분 분석이 가능하게 되었고, 스핀의 전도와 관련된 제반 문제들을 연구할 수 있게 되었다. 지금부터 10년 동안에는 포논의 측정과 전자와 포논 exciton 등이 관여된 다체계 현상, 이들의 동역학적 현상이 측정 가능하게 되었다. 핵자기 공명도 시도되고 있으며 화학적 구명 및 원자들 사이의 결합도 측정 가능하게 될 것이다. 이제 STM은 초고 진공에서 작동하는 Atomic Force Microscopy와 함께 지금까지 고체물리학 실험 장치가 만들어 내지 못하던 새로운 결과를 도출해 낼 것으로 기대한다.

• Smart Media Journal
• /
• v.9 no.1
• /
• pp.51-59
• /
• 2020

From PC communication to the development of the internet, a new term has been coined on the social media, and the social media culture has been formed due to the spread of smart phones, and the newly coined word is becoming a culture. With the advent of social networking sites and smart phones serving as a bridge, the number of data has increased in real time. The use of new words can have many advantages, including the use of short sentences to solve the problems of various letter-limited messengers and reduce data. However, new words do not have a dictionary meaning and there are limitations and degradation of algorithms such as data mining. Therefore, in this paper, the opinion of the document is confirmed by collecting data through web crawling and extracting new words contained within the text data and establishing an emotional classification. The progress of the experiment is divided into three categories. First, a word collected by collecting a new word on the social media is subjected to learned of affirmative and negative. Next, to derive and verify emotional values using standard documents, TF-IDF is used to score noun sensibilities to enter the emotional values of the data. As with the new words, the classified emotional values are applied to verify that the emotions are classified in standard language documents. Finally, a combination of the newly coined words and standard emotional values is used to perform a comparative analysis of the technology of the instrument.

• Journal of IKEEE
• /
• v.26 no.3
• /
• pp.510-514
• /
• 2022

In this paper, we propose the development of high-sensitivity low-end radiation measuring sensor module. The proposed measurement sensor module is a scintillator + photomultiplier(SiPM) sensor optimization structure design, amplification and filter and control circuit design for sensor driver, control circuit design including short-distance communication, sensor mechanism design and manufacturing, and GUI development applied to prototypes consists of, etc. The scintillator + photomultiplier(SiPM) sensor optimization structure design is designed by checking the characteristics of the scintillator and the photomultiplier (SiPM) for the sensor structure design. Amplification, filter and control circuit design for sensor driver is designed to process fine scintillation signal generated by radiation with a scintillator using SiPM. Control circuit design including short-distance communication is designed to enable data transmission through MCU design to support short-range wireless communication function and wired communication support. The sensor mechanism design and manufacture is designed so that the glare generated by wrapping a reflective paper (mirroring) on the outside of the plastic scintillator is reflected to increase the efficiency in order to transmit the fine scintillation signal generated from the plastic scintillator to the photomultiplier(SiPM). The GUI development applied to the prototype expresses the date and time at the top according to each screen and allows the measurement unit and time, seconds, alarm level, communication status, battery capacity, etc. to be expressed. In order to evaluate the performance of the proposed system, the results of experiments conducted by an authorized testing institute showed that the radiation dose measurement range was 30 𝜇Sv/h ~ 10 mSv/h, so the results are the same as the highest level among products sold commercially at domestic and foreign. In addition, it was confirmed that the measurement uncertainty of ±7.4% was measured, and normal operation was performed under the international standard ±15%.