• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2010년도 제42차 하계학술발표논문집 18권2호
• /
• pp.129-132
• /
• 2010

작금의 현대 사회 사람들은 바쁜 일상생활로 인해 짧아진 수면과 불면증 등의 각종 수면장애를 겪고 있으며, 여러 가지의 요소로 인하여 수면의 방해를 받게 되면, 여러 질병 및 생활 장애를 겪을 수 있어 수면의 중요성은 날로 주목받고 있다. 본 논문에서는 수면을 이루는 침실의 수면 환경 데이터를 수집하여 얻어진 조건 데이터들과 수면간의 관계를 분석하고 이를 바탕으로 시뮬레이션 모델을 추출하여 개개인에 따른 최적의 환경을 제공할 수 있다. 따라서 수면 과정에 따라 신체의 감각 및 자극에 대한 반응을 알고, 사람의 신체 상황에 따른 차이점 및 안정적인 패턴 및 조건을 정의하며 수면 패턴을 분석 및 솔루션 제공을 할 수 있다. 또한 차후에는 수면의 특정 상황만 아니라 식사, 출근, 등과 같은 유기적인 생활(유비쿼터스 환경)의 한 부분에도 상황에 따른 적절한 실내 환경 변화를 제공해주어서 좀 더 쾌적한 일상생활을 영위할 수 있도록 도움을 주게 되는 측면으로 확대 하려한다.

• 한국ITS학회:학술대회논문집
• /
• 한국ITS학회 2007년도 제6회 추계학술대회 및 정기총회
• /
• pp.225-229
• /
• 2007

최근에 무선 센서 네트워크는 여러 분야에서 다양하게 활용되고 있으며 간단한 환경 모니터링 시스템에서부터 기계, 구조물, 교량, 비행기와 같은 모션 모니터링과 군사, 텔레매틱스와 같은 정보량이 많고 복잡한 시스템에 적용이 시도되고 있다. 따라서 간단한 역할만 수행하면서 저 전력으로 오랜 시간 동안 운용을 목표로 해온 무선 센서 네트워크는 어려운 작업을 수행하도록 요구되고 있다. 일반적으로 무선 센서 네트워크의 MAC 프로토콜들은 주기적으로 sleep / wake를 반복하여 필요한 에너지 소비를 줄이며 이를 Duty Cycling이라고 한다. 하지만 이러한 Duty Cycling은 sleep 구간 동안에 전송할 수 없어서 홉(Hop)이 늘어날수록 전송지연이 증가하는 단점이 있다. 이러한 전송지연은 비행기 날개, 군사, 텔레매틱스 등의 복잡한 시스템이나 교통사고위험 감지 경고 시스템과 같이 빠른 데이터 처리가 필요한 시스템에서 큰 문제점이 될 수 있다. 본 논문에서는 수신 구간을 분산 배치 알고리즘(Distributed Duty Cycling, DDC)을 통하여 무선 센서 네트워크 MAC(Media Access Control) 프로토콜에서 발생하는 전송지연을 크게 줄이는 기법을 제안한다. 제안한 알고리즘은 CC2420DBK를 이용한 필드 테스트를 통해서 검증되었으며 실험 결과를 통해서 DDC 알고리즘을 통해서 전송지연을 크게 줄이고 에너지 소비 또한 감소한다는 것을 확인 할 수 있다.

• Safety and Health at Work
• /
• 제6권2호
• /
• pp.104-113
• /
• 2015

Background: Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality. Methods: Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period. Results: Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% "frequently or always") were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% "frequently or always") were statistically significant predictors of sleep quality. Conclusion: Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken.

• 가정∙방문간호학회지
• /
• 제26권1호
• /
• pp.27-35
• /
• 2019

Purpose: This study investigated sleep satisfaction and influencing factors in Korean adolescents with atopic dermatitis. Methods: Data were obtained from 4,570 subjects who completed the 2017 13th Korea Youth Risk Behavior Web-based Survey. For data analysis, descriptive statistics and multiple-sample logistic regression were used. Results: The results of this study were as follows. Gender, academic achievement, economic status, perceived stress, happiness, health status, and depression in the subjects showed a significant difference in terms of sleep satisfaction in atopic adolescents. Multiple-sample logistic regression analysis showed that male adolescents (odds ratio (OR)=0.48), academic achievement (low OR=0.67, middle OR=0.78), economic status (low OR=0.50, middle OR=0.64), lack of depression (OR=0.63), perceived stress (very OR=4.65, a little OR=2.25), perceived happiness (unhappy OR=1.99, moderate OR=1.22), perceived health status (unhealthy OR=2.17, ordinary OR=1.35), alcohol nondrinking (OR=0.75), and nonsmoking (OR=0.73) were not associated with sleep satisfaction. Conclusion: It is necessary to develop interventions that can relieve stress management and depression and develop positive emotions in atopic adolescents. In addition, there is a need to improve the environment to avoid health risks such as alcohol consumption and smoking and to minimize the effects of passive smoking.

• 한국환경보건학회지
• /
• 제40권5호
• /
• pp.376-384
• /
• 2014

Objective: The purpose of this study is to compare the health status of residents who were exposed to sources of extremely low frequency electromagnetic fields (ELF-EMFs) in the living environment and those who were not exposed to such a source of ELF-EMFs through a survey designed to appraise the residents' health levels. Method: Aimed at 251 residents exposed to a source of ELF-EMFs and 278 residents not exposed to a source, the survey was conducted to investigate the health status of the residents on the basis of questionnaire SF-36. Result: The health status scores of residents exposed to ELF-EMFs turned out to be lower than those of their counterparts. In terms of self-reported symptoms related to health and sleep quality, residents exposed to ELF-EMFs were found to have a higher complaint rate of self-reported symptoms such as dizziness, depression, and fatigue. Regarding sleep disorders, residents exposed to ELF-EMFs appeared to have a slightly higher complaint rate of sleep disorders compared to non-exposed residents. Conclusion: If a region is to be exposed to a source of ELF-EMFs, a more proactive policy for reducing such exposure is advised. In addition, it is necessary to better understand problems of residents by emplacing an ELF-EMFs risk information delivery system and building an efficient communication system for voluntary participation during the construction phase.

• 한국산업보건학회지
• /
• 제22권3호
• /
• pp.244-256
• /
• 2012

Objectives: This study was conducted to assess the level of depression and its association with sociodemographic characteristics and health related characteristics, job-related characteristics, sleep quality, occupational stress among manufacturing male immigrant worker in Korea. Methods: Total number of subject were 287 workers employed in 19 manufacturing industry. A structured self-administered questionnaire was used to assess each responder's sociodemographic and health related characteristics, job-related characteristics, sleep quality (PSQI), Korean occupational stress (KOSS), Depression (CES-D). The job stress questionna ire was used according to KOSS-26 and depression symptoms were measured using CES-D, which was translated into Korean. We used multiple logistic regression analysis to assess the relationship between risk factors included job stress, sleep quality and depression. Results: The prevalence of depression in survey subjects was 63.9%and poor group (PSQI) (5 point and over at PSQI score)among all subjects were 83.28%. Adjusting for confounding factor, higher the occupational stress (KOSS), depression levels were significantly higher (${\beta}=0.5575$), worse quality of sleep, the more depressed the level was slightly high ${\beta}=0.118$) did not reach statistical significance. Conclusions: The prevalence of depressive symptoms among the study subjects was higher than that among the Korean workers. Especially, the level of depression was more influenced by occupational stress than quality of sleep. Therefore, the author recommend to prepare the effective strategy for reducing the depression and also reducing the occupational stress among immigrant male workers, and the author consider that it need to support the convenient working environment such as consultation for difficulty or health care among immigrant male workers.

• 대한임베디드공학회논문지
• /
• 제15권5호
• /
• pp.215-225
• /
• 2020

Light detection and ranging (LiDAR) sensors detect the distance of the surrounding environment and objects. Conventional LiDAR sensors require a certain amount of a power because they detect objects by transmitting lasers at a regular interval depending on a constant resolution. The constant power consumption from operating multiple LiDAR sensors is detrimental to autonomous and electric vehicles using battery power. In this paper, we propose two algorithms that improve the inefficient power consumption during the constant operation of LiDAR sensors. LiDAR sensors with algorithms efficiently reduce the power consumption in two ways: (a) controlling the resolution to vary the laser transmission period (T_P) of a laser diode (LD) depending on the vehicle's speed and (b) reducing the static power consumption using a sleep mode depending on the surrounding environment. A proposed LiDAR sensor with a resolution control algorithm reduces the power consumption of the LD by 6.92% to 32.43% depending on the vehicle's speed, compared to the maximum number of laser transmissions (N_x·max). The sleep mode with a surrounding environment-sensing algorithm reduces the power consumption by 61.09%. The proposed LiDAR sensor has a risk factor for 4-cycles that does not detect objects in the sleep mode, but we consider it to be negligible because it immediately switches to an active mode when a change in surrounding conditions occurs. The proposed LiDAR sensor was tested on a commercial processor chip with the algorithm controlling the resolution according to the vehicle's speed and the surrounding environment.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1996년도 춘계학술대회
• /
• pp.10-13
• /
• 1996

We have developed the digital polysomnograph system to enhance the manual sleep study. This system is composed of host PC and target board. The host computer is IBM-PC Pentium 133 MHz and the target board is PC31 (processor type: TMS320C31). These two Processors communicate with each other by dualport RAM. Target board acquire 16 channel sleep signals from the Polysomnographic system (GRASS model 78, USA) and digitize them. We used high resolution monitor$(1600{\times}1280)$ to simulate the paper-recording quality of polysomnographic signal. We also implemented the GUI based polysomnographic staging program on the windows environment. Clinicians can score the sleep stage, and edit and mark the event efficiently. Finally it can support making patient database.

• Journal of Information Processing Systems
• /
• 제2권1호
• /
• pp.39-43
• /
• 2006

In this paper, we proposed TASL-MAC, a medium-access control (MAC) protocol for wireless sensor networks. In wireless sensor networks, sensor nodes are usually deployed in a special environment, are assigned with long-term work, and are supported by a limited battery. As such, reducing the energy consumption becomes the primary concern with regard to wireless sensor networks. At the same time, reducing the latency in multi-hop data transmission is also very important. In the existing research, sensor nodes are expected to be switched to the sleep mode in order to reduce energy consumption. However, the existing proposals tended to assign the sensors with a fixed Sleep/Listening schedule, which causes unnecessary idle listening problems and conspicuous transmission latency due to the diversity of the traffic-load in the network. TASL-MAC is designed to dynamically adjust the duty listening time based on traffic load. This protocol enables the node with a proper data transfer rate to satisfy the application's requirements. Meanwhile, it can lead to much greater power efficiency by prolonging the nodes' sleeping time when the traffic. We evaluate our implementation of TASL-MAC in NS-2. The evaluation result indicates that our proposal could explicitly reduce packet delivery latency, and that it could also significantly prolong the lifetime of the entire network when traffic is low.

• 디지털콘텐츠학회 논문지
• /
• 제19권3호
• /
• pp.489-496
• /
• 2018

본 연구는 공분산구조분석을 이용하여 소방공무원의 직무스트레스, 사회심리적 요인(A형 행동유형, 자기존중감, 통제신념) 및 수면의 질이 피로수준에 미치는 영향을 규명하고자 하였다. 공분산 구조분석 결과, 피로수준에 가장 큰 영향을 미치는 요소는 직무스트레스 요인에 이어, 사회심리적 요인, 수면의 질 순서로 나타났다. 이와 같은 결과는 소방공무원의 피로수준이 직무스트레스, 사회심리적 요인, 수면의 질과의 인과관계가 성립됨을 시사한다. 따라서 소방공무원의 피로수준 감소를 위한 근무환경의 개선뿐만 아니라 제도적인 뒷받침이 필요하리라 생각된다.