• The Transactions of the Korean Institute of Power Electronics
• /
• v.4 no.3
• /
• pp.285-293
• /
• 1999

In this paper, the novel digital frequency/phase controller, to control the invelter fed traveling wave type ultra-sonic m motor(USM) is proposed. This controller is used to control the drive frequency, phase difference and applied voltages of e each phase of the motor. Proposed digital controller has constructed with digital logic only, no more use digitallongleftarrowanalog h hybrid method of the conventional controller, in order to generate drive frequency and phase difference. Therefore, the c control system has become to velY simple structure. T\rvo types of controllers are designed, one is to control drive f frequency and phase difference, another has added voltage control function of each phase. Two full digital voltage/phase c controllers are implemented by using custom LSI and EPLD, the control pelformance and the simplicity ofthe proposed c controller is verified by expeJimental results.

• Journal of Biosystems Engineering
• /
• v.33 no.4
• /
• pp.282-287
• /
• 2008

Love wave is one of the shear horizontal waves and it can propagate between two layers in liquid without energy loss. The SAW (surface acoustic wave) sensor using Love wave is very useful for real time measurement of the viscosity of liquid with high sensitivity. In this study, the 77 MHz and 155 MHz Love wave SAW sensors were fabricated and use to measure the viscosity of low viscous liquid. To generate the surface acoustic wave, the inter-digital transducers were fabricated on the quartz crystal wafer. In order to obtain the optimal thickness of the coating film (novolac photoresist) generating the Love wave on the surface of SAW device, theoretical calculation was performed. The performances of fabricated Love wave SAW sensors were tested. As test liquid, pure water and glycerol solutions having different concentrations were used. Since the determination coefficients of the regression equations for measuring the viscosity of liquid are greater than 0.98, the developed Love wave SAW sensors in this study will be very useful for precise measurement of viscosity of liquid.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1986.04a
• /
• pp.71-73
• /
• 1986

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1914-1915
• /
• 2007

The period and strength of the pulse on the radial artery are important physiological factors, and they have been used to diagnosis in both Western and Eastern countries for a long time and has been developed as a unique method of diagnosis at each countries. Recently, there are a lot of systems which can give diagnosis information by recording the pulse wave and analyzing the characteristics of the pulse shape. This study describes the Pulse-Wave Measurement System which is able to measure the pulse wave signal using piezoresistive sensor and the pulse wave signal measured by the developed system is transmitted to a computer on the basis of the USB Driver. It has finally shown the the pulse wave signal measured by the sender is appeared to the host PC in real time. The Pulse-Wave Measurement System used the piezoresistive sensor to measure the pulse wave signal and the differential amplifier(AD620) to amplify the pulse wave signal which is small signal. And it used the ADC to convert analog to digital for the measured analog signal and the interface with a computer. It transmitted the measured pulse signal through USB transmission module to the host computer and Labview tool shows it. This Pulse-Wave measurement system will afford comvenience of detecting pulse wave to user related to oriental medicine.

• Korean Institute of Interior Design Journal
• /
• v.23 no.4
• /
• pp.129-139
• /
• 2014

The objective of this research is to suggest new geometric possibilities in digital architecture by investigating the characteristics of hybridization in digital geometry. The research begins with theoretical background research such as defining hybridization, investigating hybrid thinking, and studying the theory of digital geometry, along with the four conceptual characteristics of hybridization that could be drawn, such as temporality, liquidity, complexity, and connectivity. Based on these characteristics, the generative method of hybrid digital geometric languages such as Blob, Particle, Morph, Loft, and Boolean was analyzed with case research in contemporary digital architecture. As a result, diverse hybrid geometric keywords were extracted; these keywords suggest potential meanings of hybridization such as accidentality, mobility, diversity, and identity. Different elements represent the "mobility" in time by the force and wave, and they are "accidentally" combined in gradual change. The united species in "diverse" characters are seamlessly connected and emerge as a new "identity." The research maximizes the generative possibilities in digital geometry and provides a theoretical basis to apply the digital hybrid methods to architectural design by suggesting the potential meanings and possibilities in hybridization.

• Journal of the Korean Society of Costume
• /
• v.60 no.6
• /
• pp.23-36
• /
• 2010

This study set out to develop clothes made of electromagnetic wave shielding materials. Among the various worker groups exposed to electromagnetic waves for long hours, railroad workers were chosen for the study. After selecting the locations they worked, the investigator measured electromagnetic wave on the field. To examine the effects of electromagnetic wave shielding materials, I applied a lining made of electromagnetic wave shielding materials to the existing work clothes. The first experimental clothes had the silver fabric for the lining in the current working clothes, the second experimental clothes had the copper- and nickel-plate polyester placed between the outer and the lining to prevent the corrosive material from contacting the skin, and the third experimental clothes had the silver fabric for the lining and the copper- and nickel-plate polyester between the outer and the lining. The results indicate that even if a fabric is evaluated to shield electromagnetic waves after tests, it cannot completely shield electromagnetic waves emitting from everyday appliances of 60Hz. Therefore, there should be ongoing development and research efforts on fabrics that can shield electromagnetic waves to a certain degree in order to develop working clothes to alleviate fatigue for those who are constantly exposed to electromagnetic waves, relieve their anxiety, offer them psychological stability and thus help them increase job efficiency.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.11a
• /
• pp.135-136
• /
• 2023

This study is an empirical result for building an onboard communication network using metal surface wave communication and is a consideration of its application within the ship. Over the past three years, the applicability and the performance of metal surface wave communication has been confirmed by testing on five small and medium ships. In the tests, IEEE 802.11 protocol of Wi-Fi was used, and the signals were generated in the form of surface waves. Data was sent from AP to AP in the point-to-point form, and the transmission speed was measured at the same time. If necessary, additional repeaters were used to extend the transmission distance. As derived a transmission speed of 5 to 100 Mbps in wireless communication restricted areas of the 5 ships, it is believed that it is possible to reduce the weight of ships and costs by eliminating the communication cables by using surface wave communication as the back-bone network on ships.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.4 no.2
• /
• pp.67-74
• /
• 2008

Entering the 21st century, the primary influence leading world economy have been shifting. U.S. economy has seemed to slow down, Japan and EU are also in same situation. But China have started to lead Asia economy and expended to the World. According to Goldman Sachs Group, "The 21st century will be a era of Brics because of their enormous territory, a large population and abundant natural resources." We have to more focus on China because China have directly effect on Korean market and have a great potential market opportunity for our industries. However, this report mentioned above didn't carefully deal with a field of information and technology(from here IT), Digital contents consumption wasn't mentioned at all. Now Digital Contents (from here 'DC') emerge as new value creator and actually Korea has been a dominant in IT industries and is leading Digital contents market in China. This phenomenon is called as 'Korean wave (Han-Ryu)'. Many researchers have studied about 'Korean wave(Han-Ryu)' focusing on the economic effect but Korean DC industries need to build specifical strategies for exporting Korean DC to China market. Therefore, purpose of this study is following : Firstly, to analyze environment of DC in China and competitive advantages of it. Secondly, to compare ICAI (Industrial Comparative Advantage Index) according to a kind of DC. Finally, to make an analysis of China consumer's attitude to DC. This study will give much implication for Korean DC industries to enter China market.

• Journal of Digital Convergence
• /
• v.17 no.3
• /
• pp.119-128
• /
• 2019

This study examines the effect of Korean Wave recognition on the preference of cheese chicken ribs in Vietnamese students. It also examines the effect of preference of cheese chicken ribs on the Korean food image of Vietnamese students and their intention to visit Korean restaurants. We analyze the results and try to help globalization of Korean food, development of Korean menu and marketing activities. As a result of the analysis, the hypothesis that the recognition of Korean Wave has positive (+) influence on the preference of cheese chicken ribs was not adopted. The recognition of Hallyu influenced the preference of cheese chicken ribs through SNS influence. SNS influence was found to be a mediator between Korean recognition and cheese chicken rib preference. In case of foreigners, they will recognize Korean Wave through various instruments. Based on the results of this study, it is necessary to study various factors that affect the preference of Korean food and the preference of single menu, and to re - examine Korean food which can globalize Korean food.

• Proceedings of the KIEE Conference
• /
• 1989.07a
• /
• pp.162-165
• /
• 1989

This paper describes an algorithm of P-wave detection by significant point extraction method with digital differentiation. P-waves are detected by pattern matching algorithm with significant points. By means of defecting onset and offset points of P-waves, this algorithm can measure the PR intervals exactly which is important to diagnosis the atrial arrhythmia. Because P-wave duration is changed according to heart-rates, we calculate the R-R interval prior to the determination of P-wave duration threshold values in order to actively adapt to the change of P duration The results obtained from the proposed algorithm have defected successfully P-wave almost more than 90%.