• Journal of Korean Academy of Nursing
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• v.5 no.1
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• pp.70-78
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• 1975

The investigators conducted this survey to find out prevalence of diseases and symptoms of the 812 nurses who were working at the 12 Seoul city and University's hospital in Seoul by retrospective study The results of survey were summarized as follows: 1. Distribution of Prevalence Rate of Diseases and Symptoms. 1) An average prevalence rate of diseases and Symptoms of the nurses/100 persons was 64.3 cases at Present October I.1972 2) The total number of diseases and Symptoms was 522 cases at present Oct, I 1972 for the survey nurses. The prevalence rate of following diseases/100 persons were as, foot sore-11, 3. myopia-9.7, neuralgia-9.6, anemia-9.1, insomnia-8.6 cases and the corrected number percent of prevalence rate of diseases and symptoms of the above diseases into 100 denominator were as follows : foot sore-17.6% , myopia-15.4%, neuralgia-14.9%, anemia-14.2% insomnia-13.2%. 3) The prevalence rate of diseases and symptoms/100 person for the age group of 45 and over was 140.0 cases and the age of 35-39 years was 27.3 cases. 4) The prevalence rate of diseases and symptoms/100 persons by the rotation system of nurses'duty/day were as follows: two shift system rotation-86.7 cases, three shift system rotation-67.9 cases and day duty only was 56.2 cases, 5) The prevalence rate of diseases and symptoms/100 person by the basic nursing education background seemed to be lower occurrence against to the higher education and it was 94.4 cases at the Technical Nursing High School graduates. 6) The prevalence rate of diseases and symptoms/100 persons by the marital status of the nurses were as follows; single-64.8 cases, married-48, 7 cases, and widowed-28.6 cases. II. Relationship Between working Experience and prevalence of the Disease and symptoms. 1) There were no relationship by statistical test between prevalence of eye disease and experience at the eye ward(p〉0.05), skin disease and experience at the dermatology ward (p〉0.05), foot sore and experience at the operating room (p〉0.05), varicose vein and experience at the operating room (p〉0.05), sore finger and experience at the central supply room (p〉0.05), infectious disease and experience at the isolation ward(p〉0.05). 2) There was significant relationship by statistical test between pulmonary tuberculosis and experience at the tuberculosis ward (p〉0.05) prevalence of pulmonary tuberculosis was five times in experienced group than non experienced group.

• Journal of the Ergonomics Society of Korea
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• v.22 no.3
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• pp.13-26
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• 2003

The purpose of this study is to investigate the present conditions of the night work and shift work systems in the heavy chemical industrial complexes found in Changwon, Masan, and Chinhae. Korea. We will attempt to define and classify their problems; and to discover further ways to improve their systems. Fifty production factories were carefully selected as the subjects for this study. The shift systems were classified into five categories. The consecutive night shifts were long in almost all cases with 6 days (36 factories) and 7 days (13 factories). It was found that the night work of about] 2 hours continues for a long period in the weekly rotation full-day shift systems and the night-including non-full-day shift systems, and there was no holiday during a shift cycle in the continuous full-day shift systems. The work time in most shift systems was longer than the 44-hours/week permitted by Korean law. Considering the characteristics of these various types of shift systems, the most essential thing to reduce the shift workers' work load may be to shorten their working hours and improve the schedule of shift systems. It is highly recommended as a fundamental solution. to reduce the portal-to-portal hours from 12 to 8 in the night-including non-full-day shift systems and the weekly rotation full-day shift systems, and at least to employ a 4-team 3-shift system in the continuous full-day shift systems. In addition to this, it should from now on be taken as a goal to restructure the types of shift systems by taking such measures as avoiding continuous night work if possible, providing sufficient off-duty intervals both before and after night shift, providing increased opportunities for workers to nap during night work. and increasing the number of holidays.

• Journal of Industrial Technology
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• v.19
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• pp.1-7
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• 1999

This is the pre-study to pile up the basic technique for the electro-discharge machining in the field of micro-drilling. The machined chips are flowed out from the machining area by the flow arisen from the high speed rotation of the electrode. The cylindrical shape electrode, whose diameter is 0.5mm, is clamped by the three point clamping type clamper and the clamper is attached at the front shaft of the high speed rotating DC motor. The current for machining is controlled by pulse width modulation technique and the machining conditions such as frequency and duty ratio are changed to find out the effect of the variables for machined results.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.528-532
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• 1987

Closed-loop fiber-optic gyroscope with linear scale factor for a wide dynamic range is demonstrated using a gating process and two-harmonic phase modulation, of which the second harmonic is obtained by a frequency doubler. Also the effects of the second harmonic and duty cycle of gating signal on the linearity of scale factor are estimated theoretically and compared with the measured data. The experimental results show the best linearity of scale factor is about 0.5% within the rotation rate 90.deg./sec. The closed-loop fiber-optic gyroscope with gated two-harmonic phase modulation can be used in the application demanding less sensitive performance and modest scale factor linearity.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.1
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• pp.47-51
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• 2017

Generally, a working excavator has only one directional bucket tilting angle, which is up-forward. However, side direction rotation of the bucket would allow variety of working output. We designed a hydraulic rotary actuator comprising a double rod hydraulic cylinder with a rack-pinion gear set for use in excavator bucket with side tilting mechanism, thus converting the linear to angular motion. The proposed side tilting rotary actuator was designed with parts suitable for medium size of heavy duty excavator. These mechanical parts were inexpensive to purchase and the manufacturing cost was reasonable. The proposed mechanism is potentially useful for excavator with variety of working output.

• ETRI Journal
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• v.37 no.3
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• pp.480-490
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• 2015

The reliability of sensor networks is generally dependent on the battery power of the sensor nodes that it employs; hence it is crucial for the sensor nodes to efficiently use their battery resources. This research paper presents a method to increase the reliability of sensor nodes by constructing a connected dominating tree (CDT), which is a subnetwork of wireless sensor networks. It detects the minimum number of dominatees, dominators, forwarder sensor nodes, and aggregates, as well as transmitting data to the sink. A new medium access control (MAC) protocol, called Homogenous Quorum-Based Medium Access Control (HQMAC), is also introduced, which is an adaptive, homogenous, asynchronous quorum-based MAC protocol. In this protocol, certain sensor nodes belonging to a network will be allowed to tune their wake-up and sleep intervals, based on their own traffic load. A new quorum system, named BiQuorum, is used by HQMAC to provide a low duty cycle, low network sensibility, and a high number of rendezvous points when compared with other quorum systems such as grid and dygrid. Both the theoretical results and the simulation results proved that the proposed HQMAC (when applied to a CDT) facilitates low transmission latency, high delivery ratio, and low energy consumption, thus extending the lifetime of the network it serves.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.415-424
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• 2019

In this paper, a minimum rotation radius was designed and fabricated to overcome the threshold so that elderly or disabled people who have difficulty moving can move and transfer safely and conveniently in a narrow room. In the indoor environment, where the sedentary culture develops, this study aimed to provide convenience for passengers with fracture diseases, geriatric diseases, and other knee and waist diseases. First, links, seats, armrests, covers, motors, batteries, chargers, controllers, etc. were attached to the frame so that they could be moved and lifted indoors. The product design and structure were designed considering the user's environment and physical characteristics, and IoT functions were added. A driving experiment was performed to confirm the operating performance of the manufactured indoor moving and lifting wheelchair. The performance tests, such as continuous running time, turning radius, maximum actuator load, maximum lift height, sound pressure level, minimum sensing distance of the driving aid sensor, interworking of server and app programs, device compatibility, and duty cycle error rate, were performed. As a result of the test, the built-in wheelchair could achieve the performance test target of each item and operate successfully.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.220-234
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• 2013

The purpose of this study is to understand the types and features of subjectivity perceptions of the police by applying Q methodology that draw upon schematic model in subjectivity study. A survey was carried out among police officers in Gangwon province, South Korea, to classify the 61 selected Q-statements into a normal distribution using a 11 point scale. The collected data was analyzed using QUANL program, and principal component factor analysis using varimax rotation was used to identify the types of perceived image of the police. Type I can be categorized by a strong concern for the education & manpower management, Type II can be categorized by advocating for duty observance, Type III can be categorized by the pursuit of publicized police image and Type IV can be categorized by the suggestions for legal improvement. The use of Q methodology provides insights into the image of the police that would not be available through traditional methodologies and offers a foundation for essential efforts to address and overcome concerns about the image of the police.

• Tribology and Lubricants
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• v.39 no.5
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• pp.183-189
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• 2023

A bearing is a mechanical component that transmits rotation and supports loads. According to the type of rotating mechanism, bearings are categorized into ball bearings and tapered roller bearings. Tapered roller bearings have higher load-bearing capabilities than ball bearings. They are used in applications where high loads need to be supported, such as wheel bearings for commercial vehicles and trucks, aircraft and high-speed trains, and heavy-duty spindles for heavy machinery. In recent times, the demand for reducing the driving friction torque in automobiles has been increasing owing to the CO₂ emission regulations and fuel efficiency requirements. Accordingly, the research on the driving friction torque of bearings has become more essential. Researchers have conducted various studies on the lubrication, friction, and contact in tapered roller bearings. Although researchers have conducted numerous studies on the friction in the lips and on roller misalignment and skew, studies considering the influence of roller shape, specifically roller shape errors including lips, are few. This study investigates the driving friction torque of tapered roller bearings considering roller geometric uncertainties. Initially, the study calculates the driving friction torque of tapered roller bearings when subjected to axial loads and compares it with experimental results. Additionally, it performs Monte Carlo simulations to evaluate the influence of roller geometric uncertainties (i.e., the effects of roller geometric deviations) on the driving friction torque of the bearings. It then analyzes the results of these simulations.

• Korean Security Journal
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• no.21
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• pp.53-74
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• 2009

The fatigue of the Private Security Guard, such as the increase of demanded conditions, are increasing by the change of environment of inside and outside of the Society. Private Security Guard unable to solve the problem of fatigue created by their tasks has high possibility of jeopardizing their associated and citizens as well as themselves. Furthermore, fatigue can also have not good effects on Organization in various aspects. Accordingly, the problem of Private Security Guard's fatigue has significant meanings especially on effectiveness of the Organization. So this study is performed to provide implications for Private Security Guard's life quality grows by grasping not only influence that fatigue has on job attitudes, and whole relation among fatigue, Turnover Intention and Job Satisfaction that are consequences of fatigue. The private security companies of their Turnover Intention and job satisfaction from the job to the significant influence of, Dae-Jun Chungnam Province and the 215 Private Security Guards working in 20 companies. This following the summary of this study in the relation between perceptions on fatigues and Turnover Intention and Job Satisfaction, perceptions on fatigues influences on Turnover Intention.