• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.2
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• pp.169-176
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• 2010

Purpose: This study was done to investigate clinical characteristics and risk factors for sleep disturbance in patients with prostate cancer. Method: Participants were recruited from P hospital outpatient clinic from March 23 to April 20, 2006, and 101 participants completed a questionnaire assessing general and clinical characteristics, sleep quality, physical symptoms and psychological symptoms such as anxiety and depression. The data was analyzed using the SPSS 12.0 program. Results: In this study, 29.7% of the patients reported sleep disturbance. Cancer diagnosis related factors which affected sleep disturbance were onset (55.3%) and aggravation (83.3%). Habitual sleep efficiency of patients with sleep disturbance was as follows: bedtime was 10 PM, wake-up time was 6AM, sleep duration was six hours and twenty minutes. Risk factors for the presence of sleep disturbance included metastasis, the presence of intestinal symptoms, depression and anxiety. Conclusion: Sleep disturbance is a frequent problem associated with prostate cancer and seems to be influenced by aggravation of illness and the presence of physical and psychological symptoms.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.4
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• pp.248-254
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• 2013

The size and power consumption of digital circuits including the dimming circuit part will increase for high-performance solid state lighting (SSL) systems in the future. This study examined the low-power consumption of adiabatic dynamic CMOS logic (ADCL) due to the principles of adiabatic charging. Furthermore, the designed low-power ADCL digital pulse width modulation (PWM) was optimized for SSL dimming systems. For this purpose, an ADCL digital 3-bit PWM was optimized in two steps. In the first step, the architecture of the ADCL digital 3-bit PWM was miniaturized. In the second step, the clock cut-off circuit was designed and added to the ADCL PWM. As a result, compared to the original configuration, 60 transistors and 15 capacitors of ADCL digital 3-bit PWM were reduced for miniaturization. Moreover, the clock cut-off circuit, which controls wake-up and sleep mode of ADCL D-FFs, was designed. The power consumption of an optimized ADCL digital PWM for all bit patterns decreased by 54 %.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.519-521
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• 2013

무선 센서 네트워크에서는 에너지가 제한된 배터리로 네트워크를 구성하기 때문에 에너지 효율적 사용에 대한 연구가 주요한 이슈이다. 본 논문에서는 효율적인 에너지 사용을 위하여 트래픽 변화 환경을 위한 Wakeup 주기 제어 메커니즘을 제안한다. 제안되는 MAC 프로토콜은 수신자의 제어 신호로 데이터 전송이 시작된다. 송신 노드는 트래픽이 변화를 데이터 패킷 프레임에 플래그(flag)를 추가하여 수신노드에 전달한다. 수신 노드는 이를 통해 수신 노드의 Wakeup 주기를 제어한다. 제안되는 MAC 프로토콜은 트래픽이 적을 경우 수신 노드의 sleep 구간의 증가를 통하여 에너지가 절약된다. 또한 트래픽이 높은 경우 수신 노드의 Wakeup 주기를 줄여 송신 노드의 idle listening으로 발생하는 에너지 소모를 감소시킨다. 제안되는 MAC 프로토콜은 기존의 프로토콜과 비교하여 빠르게 Wakeup 주기를 조절함으로서 에너지 효율적면에서 더 좋은 성능을 보여준다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9A
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• pp.874-881
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• 2010

Acoustic signal, which is a main carrier of underwater communication, attenuates along the traveled path heavily depending on the frequency as well as inter-node distance. In addition, since it has a long propagation delay, the conventional medium access control (MAC) schemes requiring complex signaling procedures and accordingly heavy overhead messages would not be appropriate in underwater communications. In this paper, we propose a code division multiple access (CDMA) scheme as a solution for MAC of underwater communication and evaluate the performance. A hierarchical data-gathering tree topology is considered and a staggered wake-up pattern is employed for the purpose of energy saving. As a performance measure, the data rate at each level of hierarchical topology is derived.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.262-270
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• 2006

Direct numerical simulations (DNS) of turbulent channel flows up to $Re_{\tau}=1270$ are performed to investigate an elliptic feature and strain rate field on cross sections of coherent fine scale eddies (CFSEs) in wall turbulence. From DNS results, the CFSEs are educed and the strain rate field around the eddy is analyzed statistically. The principal strain rates (i.e. eigenvalues of the strain rate tensor) at the CFSE centers are scaled by the Kolmogorov length $\eta$ and velocity $U_k$. The most expected maximum (stretching) and minimum (compressing) eigenvalues at the CFSE centers are independent of the Reynolds number in each $y^+$ region (i. e. near-wall, logarithmic and wake regions). The elliptic feature of the CFSE is observed in the distribution of phase-averaged azimuthal velocity on a plane perpendicular to the rotating axis of the CFSE $(\omega_c)$. Except near the wall, phase-averaged maximum $(\gamma^{\ast}/\gamma_c^{\ast})$ and minimum $(\alpha^{\ast}/\alpha_c^{\ast})$ an eigenvalues show maxima on the major axis around the CFSE and minima on the minor axis near the CFSE center. This results in high energy dissipation rate around the CFSE.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.216-217
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• 2015

Duty-cycling could efficiently prolong the life time of Wireless Sensor Networks (WSNs) by let nodes be in dormant state most of the time, and only wake up (for sending or receiving) for a very short period. Flooding is one critical operation of WSNs. Many studies have been studied to improve the delay and/or energy efficiency of flooding. In this paper, we propose a novel time slot design, and the switching decision that reduce energy consumption for the schedule-based flooding tree. Each node, if failed to receive from its parent, will look for other candidate, among its siblings to overhear the flooding packet. By accurately collect information from other siblings, each node can make the best as possible switching decision; therefore the energy efficiency of the network is improved.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4518-4540
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• 2019

With the development of IT convergence technology, autonomous driving has gradually developed; however, the vehicle is still operated by the driver, who should always be in good health - but sometimes, this is not the case. It is especially dangerous to drive when drowsy, and unable to fully concentrate on driving, such as when taking certain medicines, or through fatigue. Drowsy driving is at least eight times more dangerous than normal driving, and as dangerous as drunk driving. Previous research has looked at technology to detect drowsiness, in order to wake up drivers when necessary, or to safely stop the vehicle. Furthermore, many studies have been conducted to find out when drowsiness occurs. However, it is more desirable for the driver to take sufficient rest during a break, in order to be able to continue to focus and drive. In other words, it is important to maintain a normal state before drowsiness. In this study, we introduce a sound source to increase driver concentration and prevent drowsiness, another that can improve the quality of sleep, and a system that produces these sound sources. The proposed system has a noise reduction effect of about 15 dB. We have confirmed that the proposed sound induces an EEG of the desired form.

• Journal of Oriental Neuropsychiatry
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• v.33 no.3
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• pp.351-360
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• 2022

Objectives: The purpose of this study was to report the efficacy of using Korean medicine treatment, for anxiety induced by chemotherapy and traffic accident. Methods: We treated a patient's anxiety with Korean medicine treatments (Yangshimtang-Gamibang, ear acupuncture, acupuncture, cupping, interferential current therapy, and herbal acupuncture therapy). To evaluate the results of this treatment, we measured the Beck Anxiety Inventory, EuroQol-Five Dimensions, Numeric rating scale, Neck Disability Index, Oswestry Disability Index, total sleep duration, time duration to fall asleep, and the number of wake-up times during sleep. Results: Improvements of the Beck Anxiety Inventory, EuroQol-Five Dimensions, Numeric rating scale, Neck Disability Index, Oswestry Disability Index, and total sleep duration were observed after the treatments. Conclusions: This study showed one case of a patient who received Korean medicine treatment for the anxiety induced by anticancer therapy and traffic accident, and improvement was observed.

• Korean Journal of Biological Psychiatry
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• v.29 no.1
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• pp.9-14
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• 2022

Objectives Sleep is fundamental to maintaining homeostatic control and has behavioral and psychological effects on humans. To better understand the function and pathophysiology of sleep, specific gene expressions in reference to sleep deprivation have been studied. In this study, we investigated the gene expression of peripheral blood mononuclear cells after sleep deprivation to better understand the functional consequence of sleep. Methods In eight healthy men, 24 h sleep deprivation was induced. Blood was sampled at 14:00, before and after sleep deprivation. mRNA was isolated and analyzed via microarrays. cDNAs before and after sleep deprivation were coupled to Cy3 or Cy5, respectively, and normalized cDNAs were selected with a ratio greater than two as a significant gene. Results are expressed as mean. Results Among 41174 transcripts, 38852 genes were selected as reliable, and only a small minority (< 1%) of the genes were up-or down-regulated. Total six and eleven genes were selected as significant upregulated and downregulated genes, respectively. Protein tyrosine phosphatase receptor type O was most upregulated (6.9-fold), and low-density lipoprotein receptor-related protein 5-like protein showed the most substantial inhibition (0.06-fold). Conclusions This study showed significant associations between sleep deprivation and the immune system. Acute sleep deprivation affects pathways in proinflammatory cytokines as well as metabolic pathways of glutamate and purine, neurotransmitters related to sleep and wake cycle.

• Transactions on Semiconductor Engineering
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• v.2 no.1
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• pp.9-16
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• 2024

This paper discusses the design of bio-implanted ultra-low-power MICS RF transceivers for wireless sensor networks. The 400 MHz MICS standard was considered for the implementation of the WBAN wireless sensor system, indirectly minimizing radio propagation losses in the human body and the inference with surrounding networks. This paper includes link budget, various transmission and reception architectures for a system design and ultra-low power transceiver circuit techniques for the implementation of RF transceivers that meet MICS standards.