• Journal of the Korea Convergence Society
• /
• v.11 no.10
• /
• pp.25-30
• /
• 2020

In this study, a test system which can test performance of curling pad was developed to support Korea curling team. The developed system consists of a water tank, a mechanical pad driving system that can perform sweeping movement using a curling pad on surface of ice made by the water tank, and temperature sensors monitoring ice and air temperatures. To control the temperature of ice and humidity/temperature of air around the ice, all system are installed in a chamber that can isolate the developed system from external environment. Eight kinds of curling pads were tested using the developed system. Test result showed that each curling pad revealed different rate of ice temperature increasing. The pad with the highest rate of ice temperature rising was found to be the same as the most preferred pad by the athletes. Therefore, it was confirmed that the method of measuring change of ice temperature by the sweeping performed in this study is an effective method to test the performance of the pad.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.5
• /
• pp.913-922
• /
• 2020

In this paper, we propose a LoRa communication module using the LoRa RF module of Murata Electronics is designed to configure the IoT digital meter remote meter reading and a method of configuring a remote meter reading network by collecting multiple meter data in a DCU (Data Concentrate Unit) to configure a network with LoRaWAN. The developed system can be installed more easily and economically in the network configuration than the existing system by allowing the meter to be directly connected to the network or matched with a DCU to connect to the network according to the configuration of the consumer. The developed system was constructed using a digital water meter as an example, but it can also be applied to remote meter reading of the metered values of other meters such as electricity, water, gas, hot water and calorie meters. The main development contents are the design, configuration, and construction of digital meters, LoRa modules and DCUs, and how to connect the LoRaWAN network and transmit meter data to the server. By networking these devices, the system is configured, and the actual LoRaWAN communication is tested and the result is shown.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.371-372
• /
• 2008

Many kinds of electrodes have been developed in various forms and shapes for measurement of bio potential signal. Textile electrode has benefit of collect long tenn data monitoring because of it is non-consciousness, convenient and do not occur skin irritation. However, It is very difficult to acquire available data due to high impedance of electrode and unstable skin-electrode contact which generate motion artifact. Also snap button which usually used as mediator between textile and measurement device cause change of electrical characteristics. In this paper, we inflated textile electrode to stabilize contact and add conductive silver paste between textile and snap button to improve conductance. To compare the performance of two methods, flat or inflated and add conductive paste or not, four types of electrodes are tested on each impedance and SNR by ECG measurement. In result, the first type electrode which flat and non-conductive paste showed the worst performance and the last type electrode which is inflated shape and contain conductive paste show the best performance.

• 대한공업교육학회지
• /
• v.30 no.1
• /
• pp.46-55
• /
• 2005

The purpose of this study is to contemplate the relationship between a cognitive styles(field-independence/dependence, Fl/D)and a technological problem solving(TPS) among the industrial high school students. When it comes to perception, remembrance and consideration, we all have our own individual and steady patterns. We call them cognitive styles. FI/D is one kind of cognitive styles and it is about how dependently we perceive the field which each object has. Custer(1995) presented the technological problem among problem solving existed in various types as organizing it with four conceptional frames, which are invention, design, trouble shooting and procedures. We tested 56students belong to B industrial high school in A city, Korea. We used Group Embedded Figures Test(GEFT) to experiment the FI/D cognitive styles. We also did the TPS test by using an appliance which a researcher has developed. The appliance was made according to the technological problem and its validity was justified by an expert. We came up with a correlation coefficient between the FI/D cognitive styles and TPS to figure out what kind of relationship those two variable factors have and how much they are correlated each other. The correlation coefficient turned out ".59" which means they have significant and positive correlation.To find out the TPS difference between FI group and FD group, we compared each group's TPS score. As a result of the analysis, the FI group's TPS score is significantly higher than FD group's one.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.2
• /
• pp.721-727
• /
• 2013

This study sought to compare the difference of Phonation Threshold Pressure and Nasalance according to vowels. We tested 28 normal females(20~30age) who be in attendance at a school from May to August 2012. We measured Phonation Threshold Pressure through PAS(Phonatory aerodynamic system, model 6600, KAY electronics, Inc) that aero-mechanical instrument called. Phonation Threshold Pressure was measured by using the consonant /p/ and the three vowels /a, i, u/ and was analyzed the three times of Phonation the five times. Also We measured Nasalance through the Nasometer${\Pi}$(model 6450, KAY electronics, Inc). The vowel's phonation was recored by using the three vowels /a, i, u/. the nasalance score was measured via Nasometer. As a Result, Phonation Threshold Pressure according to three vowels show significantly difference. Also, Nasalance according to three vowels show significantly difference. Finally, Correlation coefficient of Phonation Threshold Pressure and Nasalance according to three vowels show positive relation ship. Therefore Phonation Threshold Pressure and Nasalance according to three vowels have closely relationship.

• Korean Journal of Human Ecology
• /
• v.14 no.2
• /
• pp.293-302
• /
• 2005

The purpose of this study is to compare hair care behaviors between Korean and Australian women whose individual hair characteristics, social backgrounds, and culture were different from each other. Then, this study also aims to provide some basic data for professionals in the field of beauty education and industry. Data were collected through a survey with 208 Australian females and 392 Korean females. Analyses included t-test, frequency analysis, and one-way ANOVA. The results are as follows: The Korean women mostly had black and brown natural hair, and 68.4% of them had color. On the other hand, the Australian surveyees had brown and dark blonde, and 85.4% of them had color. They both were asked why they were using hair products. The Koreans responded that they were for hair moisturization, while the Australians said they were for producing a hair style they wanted. In addition, the Koreans made the most use of a hair conditioner and hair wax, while the Australian women did a hair spray and gloss. As far as the satisfaction with beauty salon service goes, the Australian respondents showed more service satisfaction than the Koreans on average. The homogeneity of the two nations' average points was t-tested. The result indicated that significant differences existed in the hair shop satisfaction with services, such as dyeing, haircut, blow dry, shampooing and massaging, and staff attitudes.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.1
• /
• pp.93-107
• /
• 2016

Game bot playing is one of the main risks in Massively Multi-Online Role Playing Games(MMORPG) because it damages overall game playing environment, especially the balance of the in-game economy. There have been many studies to detect game bot. However, the previous detection models require continuous maintenance efforts to train and learn the game bots' patterns whenever the game contents change. In this work, we have proposed a machine learning technique using the self-similarity property that is an intrinsic attribute in game bots and automated maintenance system. We have tested our method and implemented a system to major three commercial games in South Korea. As a result, our proposed system can detect and classify game bots with high accuracy.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.30 no.4
• /
• pp.559-572
• /
• 2020

As internet technology advances, users can share content online, and many sharing services exist. According to a recently published digital forensic study, when playing an online streaming service, you can restore the played video by reconstructing the Chrome cache file left on local device such as a PC. This can be seen as evidence that the user watched illegal video content. From a different point of view, copyright infringement occurs when a malicious user restores video stream and share it to another site. In this paper, we selected 23 online streaming services that are widely used both at home and abroad. After streaming videos, we tested whether we can recover original video using cache files stored on the PC or not. As a result, the paper found that in most sites we can restore the original video by reconstructing cache files. Furthermore, this study also discussed methodologies for preventing copyright infringement in online streaming service.

• Journal of Navigation and Port Research
• /
• v.32 no.5
• /
• pp.349-353
• /
• 2008

In this paper, the EM wave absorber was designed and fabricated for preventing Reader Interference of RFID communication system in UHF band We fabricated several samples in different composition ratios of Amorphous and CPE(Chlorinated Polyethylene). Absorption abilities were simulated in accordance with different thicknesses of the prepared absorbers and changed complex relative permittivity and permeability due to composition ratio. The mixing ratio of Amorphous and CPE was searched as 80 : 20 wt.% by experiments and simulation. Then the EM wave absorber was fabricated and tested using the simulated data. As a result, the developed EM wave absorber has a thickness of 4 mm and absorption ability was over 20 dB in frequency range of $860\;MHz{\sim}960\;MHz$. Therefore, it was confirmed that the developed absorber can be used for suppressing RFID reader interference in UHF band.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.3
• /
• pp.281-288
• /
• 2002

This paper has realized a control system of a vibrator using PM excited Transverse Flux Linear Motor(TFLM). Proposed vibrator can supply a vibration force up to 700[N] at rated current, wide operation range of vibration displacement and high frequency for a tested structure. Also, volume of a vibrator system can be decreased because of a high trust force rato(a thrust force per weight=N/Kg). A proposed vibrator instead of a hydraulic vibrator can improve efficiency and have may advantages of maintenance and management. A desired value command is a vibration frequency and displacement in a controller for a vibrator system and a controlled values we a instant position and velocity of a mover Output value of the controller is phase current controlled by PWM converter. In this research, Dynamic simulation has been executed for analysis of a control algorithm and dvnauuc characteristics and is compared with experimental result.