• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2638-2647
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• 2010

X-MAC reduces transmission delay and energy consumption by using a short preamble instead of the existing long preamble. To solve the problem of X-MAC, this paper proposes a new MAC protocol called Express-MAC. The wireless sensor network is mainly used for the purpose of gathering event data or situation information. Especially, the transmission pattern of the sensor network with the purpose of event detection such as intrusion detection is very intermittent as well as successively occurring when a single event takes place in most cases. By reflecting sensor network's key transmission patterns as above, EX-MAC has used multi-hub path's path reservation system and awake section's transmission time reservation method in data transmission when the first event takes place. The awake time reservation in transmission path has improved successive data transmission's end-to-end delay, and it has also increased efficiency in terms of energy consumption by reducing the preamble length of data transmission and reception node.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.4
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• pp.297-305
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• 2017

Background: Fiberoptic nasotracheal intubation (FNI) is performed if it is difficult to open the mouth or if intubation using laryngoscope is expected to be difficult. However, training is necessary because intubation performed by inexperienced operators leads to complications. Methods: Every resident performed intubation in 40 patients. Success of FNI was evaluated as the time of FNI. First intubation time was restricted to 2 min 30 s. If the second attempt was unsuccessful, it was considered a failed case, and a specialist performed nasotracheal intubation. If the general method of intubation was expected to be difficult, awake intubation was performed. The degree of nasal bleeding during intubation was also evaluated. Results: The mean age of the operators (11 men, 7 women) was 27.8 years. FNI was performed in a total of 716 patients. The success rate was 88.3% for the first attempt and 94.6% for the second attempt. The failure rate of intubation in anesthetized patients was 4.9%, and 13.6% in awake patients. When intubation was performed in anesthetized patients, the failure rate from the first to fifth trial was 9.6%, which decreased to 0.7% when the number of trials increased to > 30 times. In terms of awake intubation, there was no failed attempt when the resident had performed the FNI > 30 times. The number of FNIs performed and nasal bleeding were important factors influencing the failure rate. Conclusion: The success rate of FNI increased as the number of FNI performed by residents increased despite the nasal bleeding.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.750-755
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• 2007

The linear SEF (Spectral Edge Frequency) parameter and spectrum analysis method can not reflect the non-linear of EEG. This method can not contribute to acquire real time analysis and obtain a high confidence in the clinic due to low discrimination. To solve the problems, the development of a new index is carried out using the bispectrum analyzing the EEG including the non-linear characteristic. At the bispectrum analysis of the 2 dimension, the most significant's power spectrum density peaks appeared much at the specific area in awake and anesthesia state. Because many peaks are showed at the specific area in the frequency coordinate, these points are used to create the new index. Range of the index is 0-100. At the anesthesia, the index is 20-50 and at the awake, the index is 90-60. New index can discriminate the awake and anesthesia state.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.43-50
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• 2008

In IEEE 802.11b wireless LAN, stations keep synchronization by receiving beacons being periodically sent by the AP (access point) when they run in low power mode. Beacon transmission is delayed if wireless channel is busy at a scheduled TBTT (target beacon transmission time), and stations must be awake until they receive the delayed beacon. In this paper, we propose a scheme that stations get their transmission delayed if they have little time for successful data transmission by the next TBTT. Beacon transmission without delay is guaranteed at every TBTT with this method so that the awake time of low power stations to receive beacon can be reduced. The proposed method is simulated and its characteristics ore described with the analysis of the results. The measured results in terms of beacon delay show some enhancement in energy consumption.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.503-508
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• 1992

A new method for making automatic electroencephalogram(EEG) report based on the automatic quantitative interpretation of awake EEG was developed. We first analysed a. relationship between EEG reports and quantitative EEG interpretation done by a qualified electroencephalographer(EEGer) for 22 subjects. Based on the analysed relationship and usual process of report making by the EEGer, we defined all terminology necessary for EEG report and established rules for EEG report making. By the combined use of the proposed EEG report making and the method for automatic quantitative EEG interpretation presented at '90 KACC, we were able to make the automatic EEG reports which were equivalent to the EEG reports written by the EEGer. As all the procedures were programmed in a personal computer equipped with an AD (analogue-to-digital) converter, the automatic EEG reports were obtained in almost real time in usual actual EEG recording situation with only a few seconds time lag for the analysis in the computer. The proposed report making method and the quantitative EEG interpretation method will be effectively applicable to the clinical use as an assistant tool for physicians.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.360-365
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• 2010

In this paper, we present a distributed algorithm for detecting dynamic event regions in wireless sensor network with the consideration on energy saving. Our model is that the sensing field is monitored by a large number of randomly distributed sensors with low-power battery and limited functionality, and that the event region is dynamic with motion or changing the shape. At any time that the event happens, we need some sensors awake to detect it and to wake up its k-hop neighbors to detect further events. Scheduling for the network to save the total power-cost or to maximize the monitoring time has been studied extensively. Our scheme is that some predetermined sensors, called critical sensors are awake all the time and when the event is detected by a critical sensor the sensor broadcasts to the neighbors to check their sensing area. Then the neighbors check their area and decide whether they wake up or remain in sleeping mode with certain criteria. Our algorithm uses only 2 bit of information in communication between sensors, thus the total communication cost is low, and the speed of detecting all event region is high. We adapt two kinds of measure for the wake-up decision. With suitable threshold values, our algorithm can be applied for many applications and for the trade-off between energy saving and the efficiency of event detection.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.287-293
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• 2007

The researchers have studied for a long time about the depth of anesthesia but they don't make criteria for the depth of anesthesia. Anesthetists can't make a prediction about patient's reaction. Therefore, patients have potential risk such as poisonous side effect, late-awake, early-awake and strain reaction. In this study, the distributed characteristics on the bispectrum and bicoherence, the type of nonlinear signal processing, as a result of the coupling of EEG were presented according to depth of anesthesia. These results were consistent with a trend of delta ratio that the index of evaluation for the depth of anesthesia. The higher-order spectrum (HOS), the bispectrum and bicoherence, gives the useful information about depth of anaesthesia than other indexes.

• Korean Parent-Child Health Journal
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• v.3 no.1
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• pp.60-72
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• 2000

Studies are needed to determine the standard norms for sleep/activity patterns in new born baby and there have been no established reports of discrepancy of sleep/activity patterns in new born baby among various races. The purpose of this study is to determine whether the NCASA(Nursing Child Assessment Sleep Activity Record) would be suitable to evaluate and to provide the basic resources for a Korean model of sleep/activity patterns during the new born baby, and to provide a basis for nursing intervention for mothers of new born baby. The subjects of this study were 38 normal new born baby who visited the postpartum care center and two general hospitals located in pusan from January 1 to April 28, 2000. They all agreed to participate in this study. The method of data collection was through convenient sampling. Data were collected through questionnaires including demographic data, birth hi story, and general informations concerning the infant, mother and family. The instrument of this study was the NCASA translated by the Korean parent Child Health Academic Association. The collected data were analysed by mean. standard deviation, frequency, and percentage by use of SPSS/PC. The conclusions obtained from this study are summarized as follows: 1. The mean amount of daytime sleep was 10.23 hours. The mean amount of nighttime sleep was 5.53 hours. The mean amount of total daily sleep was 15.77 hours. The mean of the longest sleep period was 4.49 hours. The mean regularity of daytime sleep was 49.69%. The mean regularity of nighttime sleep was 66.98%. The mean regularity of total daily sleep was 55.81%. The mean frequency of nighttime wakenings was 3.09 times. 2. The mean amount of daytime awake periods was 6.12 hours. The mean amount of nighttime awake periods was 2.11 hours. The mean amount of daily total awake periods was 8.23 hours. The mean of the longest awake periods was 3.76 hours. 3. The mean frequency of daytime feeding was 5.71 times. The mean frequency of nighttime feeding was 2.65 times. The mean frequency of total daily feeding was 8.36 times. The mean frequency regularity of feeding was 62.50%. 4. The mean amount of a mother's day time was 16.36 hours. The mean amount of a mother's night time was 7.64 hours. In conclusion, The new born baby slept more during the daytime compare than nighttime and more active during the daytime. On the other hand. although nighttime sleeping the length of the mother was normal, but sleep was interrupted by the infant over 3 times on average. Therefore this research study will contribute to nursing practice and nursing research by its implication through postnatal educational nursing programs at hospital and nursing intervention programs that would help individual caring of early infant mothers at home.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.382-387
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• 2011

Whether a person is feeling sleepy or reasonably awake is important safety information in many areas, such as humans operating in traffic or in heavy industry. The changes of body signals have been mostly researched by looking at electroencephalogram(EEG) signals but more and more other medical signals are being examined. In our study, an electrocardiogram(ECG) signal is measured at a sampling rate of 100 Hz and used to try to distinguish the possible differences in signal between the two states: awake and drowsy. Practical tests are conducted using a wireless sensor node connected to a wearable ECG sensor, and an ECG signal is transmitted wirelessly to a base station connected to a server PC. Through the QRS complex in the ECG analysis it is possible to obtain much information that is helpful for diagnosing different types of cardiovascular disease. A program is made with MATLAB for digital signal filtering and graphing as well as recognizing the parts of the QRS complex within the signal. Drowsiness detection is performed by evaluating the R peaks, R-R interval, interval between R and S peaks and the duration of the QRS complex..

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.751-757
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• 2007

Objectives : The aim of this study was to provide basic background information on stroke by evaluating various etiological factors on the basis that the onset time of cerebral infarction varies according to its cause. Methods : We studied hospitalized patients within 4 weeks after their ictus who were admitted at Kyunghee OMC, Kyungwon OMC, or Donguk Ilsan OMC from [month] $1^{st}$, 2005 to June $30^{th}$, 2007. We compared the general characteristics of acute stroke patients according to onset time. Results : Regardless of the onset time, the distribution of cerebral infarction patterns showed high SVO. The onset time did not show significant difference for average age, height, weight, BMI, waist measurement, hip measurement, or waist/hip ratio between onset during sleep and awakening. Patients whose stroke occurred while awake were more likely to have a past history of HTN, DM, ischemic heart disease, or atrial fibrillation but did not show significant difference according to their onset time. Conclusions : The above results show that the overall tendency of acute stage cerebral infarction patients varies according to their onset time. This study was carried out on the basis of previous findings that cerebral infarctions that occurred during sleep were more likely to have been caused by cerebral thrombosis, and strokes that occurred while awake were more likely to have been caused by cerebral embolism. However, there were no statistically relevant results, so a larger study group is needed to research the tendency of stroke patients.