• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.654-657
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• 2005

The aim of this study is to investigate and to analyze the reverberation times of apartment houses Measurements were conducted in a total of 44 rooms(36 rooms were in occupied houses and 8 rooms were in unoccupied houses) according to KS F 2864. The results showed that the averaged reverberation time of the occupied and the unoccupied houses were about 0.3$\sim$0.5sec and 1.2$\sim$l.5 sec, respectively, at 500Hz octave band frequency. And the averaged absorbtion coefficient of the occupied and the unoccupied houses were about 0.13$\sim$0.35 and 0.11$\sim$0.20, respectively. In addition, We verified that the reverberation time generally depended on the frequency; the lower the frequency, the higher the reverberation time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10A
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• pp.987-996
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• 2008

In this paper, the conventional anti-collision algorithms, such as Channel Monitoring algorithm and Pulse Protocol algorithm are analyzed. To decrease tag identification time, and increase system throughput and efficiency, we propose a new reader anti-collision algorithm, Pulse Protocol-based Hybrid Reader Anti-collision Algorithm, using Slot-occupied Probability under dense reader environment. The proposed algorithm uses Slot-occupied Probability to improve the performance of Pulse Protocol Algorithm. That is, A reader checks Slot-occupied Probability after generating random backoff time. If Slot-occupied Probability is greater than 0, it uses another new random backoff time to avoid reader collision. We also compare the performance of the proposed algorithm with those of Channel Monitoring and Pulse Protocol algorithms in respect of identification time system throughput, and system efficiency. Simulation results show that the proposed algorithm has an increment of 5% of identification time and system throughput as increasing the number of readers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2437-2445
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• 2012

This paper presents the efficient measurement method of radio resource by analyzing various medium occupied elements. The medium occupied time consists of 802.11 frames, wireless interference, and protocol waiting time from a wireless node on a current channel. And it is used to performance metric. Existing research is only measured partial occupied elements, and is lack of validation of measurement unit and scalability on various IEEE 802.11 radio. This paper presents the measurement method of classified occupied elements. To achieve this, we modified 802.11n based OpenHAL device driver to collect the register information of wireless chipset, and to analyze receiving frames in an virtual monitor mode. We conclude accurate medium occupied time measurement system from various validation methods.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3156-3158
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• 1999

Occupancy sensor is a efficient light control system which light on/off automatically and reduces the unnecessary power waste. From now the research on occupancy sensor is restricted to the selection of the appropriate place or sensor. Exist occupancy sensor changes the delay time by manually to the place or situation, so it is unreliable. The delay time can been changed by the average time of the occupied and the preset time, but it is not enough to reliable. In this paper, so to acquire the reliance the average and the standard deviation of the occupied time change the delay time automatically and protect the malfunction from the detector. And to embody it, AT89C52 microcontroller is adopted to the control circuit. It is verified by simulation and experiment results of output characteristic for randomized input.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.167-172
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• 2012

This paper aims on comparative analysis of measuring efficiency of occupied bandwidth between MRTG average traffic and internet real-time traffic by measuring the type of internet application service. Through this analysis, the user can measure their internet line and occupy a certain amount of bandwidth and will have to invest on how much is compared to MRTG maximum traffic graph. The result of measurement proved 1.4 times to 20 times occupied bandwidth error rate between real-time and average traffic by the type of internet services.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.705-713
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• 2007

The purpose of this study was to understand the organization and the forestry household income applied the result of 2005 Forestry Census and the Economic survey of Forest household in Korea. As a result of the analysis, there are 97,108 households of a forester in korea 2005. Full time forestry household occupied 7,925 families (8.2%), part time forestry household occupied 88,183 families (91.8%). Therefore, the most household of a forester is part time forestry household in korea. The average people of the household of a forester family is 2.7 people. The age of forest manager are sixties nearly, over sixty years old forest manager occupied 51,505 people (53%). The forest management period of forestry households is more than 6 months in 39,229 families (40.4%), less than 1 month in 7,216 families (7.4%). The average area of forestry households owning forest is 4.6ha. According to the type of business, logging families possesses 19.5 ha. The mean income of forestry households is \27,148,000. One of them, forestry income is \6,529,000, which occupied 24.1%. Furthermore, forestry households less than \5,000,000 forest product sales performance occupied 51,633 families, which is 64%. Forest operating costs is \6,566,000 mean per family. In addition, the number of a forestry household resident villages is 11,829 villages, where is 32.8% of whole villages in korea. There are 2,979 villages where reside forestry household in gyeongsangbuk-do.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.46-52
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• 2012

During the past decades, energy and Green House Gas(GHG) emissions has risen as a global issue. This paper is about the energy intensity and the GHG intensity in a university campus using the weighting factor of total occupied time to the members of the university. Through this analysis, we could separately estimate GHG intensity per full-time and part-time members under the situation that the measuring data is not perfect. This analyzing procedure could be applied to other non-manufacturing institutions such as school, hospital, governmental institute, office building etc.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.6
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• pp.299-311
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• 2008

The Radio Frequency IDentification (RFID) system is a contactless automatic identification system, which comprises readers and tags. In RFID systems, a reader collision occurs when there is interference in communication between one reader and the tags, due to the signals from other readers. The reader collision problem is considered as the fundamental problem affecting high density RFID reader installations. In this paper, we analyze the existing reader anti-collision algorithms. We also propose a pulse protocol-based reader anti-collision algorithm using slot occupied probability (SOP). The implementation of this improvement is simple, yet it effectively mitigates most reader collisions in dense reader mode, as shown in our simulation. That is, the proposed algorithm reduces the identification time, and increasesthe system throughput and system efficiency compared with the conventional reader anti-collision algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1593-1598
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• 2012

In this paper, we propose an intelligent signal control method based on fuzzy logic applicable in real time. We design membership functions to model occupied time and the number of vehicles for each lane. A priority for each signal phase is computed by the popular Max-Min fuzzy inference based on control rules and membership degrees of prepared two functions at any given time. A tie breaking scheme is considering weighted sum of the rate of occupied time per number of vehicles in that block and the standard deviation of these blocks. Only a signal phase with the highest priority is opened and all others are closed and the duration of the phase opening is computed proportional to the rate of number of weighting vehicles in that signal per all weighted vehicles. The simulation result shows that the proposed method is more efficient than the static control in all simulation conditions in $2{\times}3$ experimental designs with the number of vehicles in intersection and congestion degrees that have all three levels.

• Research in Community and Public Health Nursing
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• v.4 no.1
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• pp.77-83
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• 1993

This study was carried out to idedtify Worker's general health diagnosis and specific health diagnosis state and provide the basic data about occupational health nursing services in Kyung Sang Nam Do. Data was obtained from 36 industry in Chang-won, Jin-joo, Geo-jeoi, Chung-moo area during Dec. 20. 1992-Feb. 18. 1993 through questionaire survey. Data was analyzed into frequency, percentage, average, standard deviation and score sum The main findings are as follows : 1) 83.3% of subject was manufactures. The factory which have over 1000 Worker's are 41.7% and 500-999 are 36.1%. 2) Health managers are composed of 5 man power. Doctors occupied in 44.4% of factories, average age of them are 43.9 years, average careers are 4.0 years. Nurses occupied in all factories and their average ages are 27.6, average careers are 3.0 years. Industrial hygienist occupied in 33.3% of factories, environmental hygienist occupied 69.4% of industries, and nurse aids occupied in 19.4%. 3) 99.9% of workers are received general health diagonosis. And 10.8% of workers are received elaborate health diagnosis. Among them 30.9% are C class and 23.4% are D class. Among D class, 50% of workers are treated as work time shortening, work replacement, being under treatment. Total specific health diagnosis' subject are 19.3% of workers but 79.9% of them are received specific health diagnosis. Among them 18.6% are needed follow up treatement. Only 44.9% of them are received follow up treatement. 4) 69.4% of industries have their referral hospital and 97.2% have their clinics. Among Occupational health services, health diagnosis are carried out first. of all and the next, environmental management, industrial diagnosis, health education are carried out.