• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.400-405
• /
• 2008

Motor is energy converting system to generate mechanical force from electrical power and there are various typed motors in home, office, factory, vehicles, aircraft, shipping, etc. Recently in compliance with performance and reliability and the applications of variable speed motors with invert driver are expanded. Almost high power inverter have IGBT and IGBT's fault cause motor system fault. If we can calculate and foresee troubles of IGBT, we can protect accident caused by motor system fault. In this paper, the deterioration test method of IGBT devices is proposed and the test results of proposed method are shown by evaluated equipment. The basic concept of proposed method is current-voltage characteristic curve test between drain and source of IGBT in open state. The applied voltage type is ramp and it is confirmed that the current-voltage curvet pattern of IGBT in open state represents IGBT's deterioration state.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.540-544
• /
• 2009

Hydrologic pattern under climate change has been paid attention to as one of the most important issues in hydrologic science group. Rainfall and runoff is a key element in the Earth's hydrological cycle, and associated with many different aspects such as water supply, flood prevention and river restoration. In this regard, a main objective of this study is to evaluate design flood using simulation techniques which can consider a full spectrum of uncertainty. Here we utilize a weather state based stochastic multivariate model as conditional probability model for simulating the rainfall field. A major premise of this study is that large scale climatic patterns are a major driver of such persistent year to year changes in rainfall probabilities. Uncertainty analysis in estimating design flood is inevitably needed to examine reliability for the estimated results. With regard to this point, this study applies a Bayesian Markov Chain Monte Carlo scheme to the NWS-PC rainfall-runoff model that has been widely used, and a case study is performed in Soyang Dam watershed in Korea. A comprehensive discussion on design flood under climate change is provided.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.2
• /
• pp.56-60
• /
• 2021

Recently, technologies for internet of things have been rapidly advanced with development of network. Also interest in smart healthcare that informs about motion information of users has been growing. In this paper, a system that is monitoring the weight on both feet by using aduino and FSR(Force Sensitive Resistor) Sensor is implemented. A 4-channel sensor driver module was implemented to measure a more accurate weight value. It is monitoring the weight on both feet by the using an application for either your PC or mobile device. Mobile applications can contribute to reducing human damage by sending messages along with location in emergency situations, such as injuries caused by falls during outdoor activities.

• Journal of the Korean Society of Safety
• /
• v.30 no.6
• /
• pp.40-47
• /
• 2015

In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length ${\times}$ 50 cm height ${\times}$ 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in $218^{\circ}C{\sim}995^{\circ}C$ at 30 seconds and $501^{\circ}C{\sim}1078^{\circ}C$ at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of $501^{\circ}C$ was shown at 300 seconds and marble inner wall showed the following lowest temperature of $900^{\circ}C$. Temperature rising over $1000^{\circ}C$ was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.6
• /
• pp.74-87
• /
• 2020

Overloaded trucks are the main source that threatens road safety and directly affects the reduction of pavement life. The On-board truck scale is the only equipment that could prevent overloading by measuring and adjusting the loading weight before driving. Legislation is needed to encourage its installation so that the driver can prevent overloading. In this study, an on-board truck scale system was installed on 30 dump trucks for transporting construction waste, such as soil and aggregates, which are major loads of 36.55% for overloading, and the trucks were monitored remotely. The overload prevention effect was analyzed by comparing driving data for 1 month before distribution of the weight display app that can recognize the weight to the driver and 1 month after distribution. After installation, overloading could be 6.1% reduced, and the transportation efficiency could be increased by checking the weight provided from the On-board truck scale system.

• Fisheries and Aquatic Sciences
• /
• v.25 no.2
• /
• pp.101-116
• /
• 2022

The harvesting season of lompa fish, Thryssa baelama, through sasi, indigenous knowledge in resources management, in Haruku Village has become a socio-cultural event that attracts many people. The sasi of lompa fish has been conducted for hundreds of years. Information on the bioecology aspect of lompa fish is limited, while this information is crucial for lompa fish sustainability through the sasi approach. This study aimed to investigate some population parameters of lompa fish, its sustainability status, and proposed a sustainable management strategy for the lompa fishery of Haruku Village. Fish population parameter covers length-weight relationship, growth pattern, size distribution, sex ratio, and the body condition index. The sustainability status was assessed following the Rapfish approach. Fisheries management strategy was performed using a conceptual model framework based on Driver Pressure State Impact Response. The research shows that the total length varies between 9.2-14.3 cm. A high relationship was found between total length and weight, and the growth pattern was an allometric negative. There was a difference in sex ratio between males and females, with females dominant. The body condition index varies over time, probably due to reproductive status. The overall sustainability status was at fair condition (61.60%), with the ecological domain having the highest sustainable status (71.07%) and considered sustain. In comparison, the technological domain had the lowest sustainability status (52.58%) and was considered fair sustain. There were seven management strategies proposed for sustainable management for the lompa fishery.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.48 no.1
• /
• pp.65-71
• /
• 2011

In modem society, car are the most important transportation. Thereby, car accidents has been increasing steadily. The driver is the biggest factor of car accident. Therefor, various studies about driver (reaction time, mentality, physiological signal, age, pattern of drive) are underway. In this paper, we design a embedded system for measuring the reaction time by driving skill. The proposed system is composed of measuring brake module, OBD-2 scanner and bluetooth transmission module. Also, we implement GUI program to analyze experiment result and database to store results. Though our proposed system, we can analyze driving skill.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.6
• /
• pp.560-568
• /
• 2005

The proposed Multi-level PDP sustain Driver is composed of the semiconductor devices with low voltage rating compared to those used in the prior circuit proposed by L. Wether, and it has two resonant periods during the charging (rising period) and discharging (falling period) the PDP in the sustaining voltage waveforms. In accordance with the change of timing phase$(T_{r1},\;T_{i1},\;T_{r2})$, the performance characteristics of a commercial PDP module has been carried out and compared the characteristic with the 42V6, made of LG Electronics co., Experimental results show that the performance characteristics of PDP module are greatly influenced by the variation of $T_{i1}\;and\;T_{r2}$. The variation of $T_{r1}$ do not influence much on the performances of PDP. With the conditions that $T_{r1}=60ns,\;T_{i1}=120ns,\;and\;T_{r2}=350ns$, we could get the performances listed as the luminance is increased $14.6\%$, the power consumptions is decreased $5.9\%$, the panel efficiency is increased $24.2\%$, module efficiency is increased $21.2\%$, compared to those shown in the commercial PDP module (42V6). Therefore, the proposed multi-level PDP sustain driver expected to be suitable to actual PDP module application.

• Journal of the Ergonomics Society of Korea
• /
• v.25 no.4
• /
• pp.129-135
• /
• 2006

he purpose of this study is to measure bio-signal to investigate the driver's physiological response change under real situation using train simulator. The train simulator used in this study is KTX model and according to changes of driving situation, The bio-signal controlled by autonomic nervous system, such as GSR(Galvanic Skin Response), SpO2(Saturation percent O2), HR(Heart Rate), ECG(Electrocardiograph), EEG(Electroencephagram) and movement and response of eye were measured. Statistically significant difference in bio-signal data and eye movement activity pattern were investigated under several different driving speeds using analysis of variance (p<0.05). The GSR and HR value measured in average and mission speed operation is higher than in high-speed operation. β wave of EEG in average speed operation become more activated than in high speed operation. In accordance with a characteristic of rail vehicle, movement and response of eye in high-speed operation requiring relatively simple maneuver become less activated than in either average or mission speed operations. Conclusively, due to more careful driving controls in average and mission speed operation are required than in high-speed operation, level of mental and physical stresses of train driver was increased and observed through changes of bio-signal and eye movement measured in this study.

• Journal of Forest and Environmental Science
• /
• v.34 no.6
• /
• pp.419-428
• /
• 2018

Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.