• 산업경영시스템학회지
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• 제35권4호
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• pp.33-40
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• 2012

Dentists are known to be highly exposed to the musculoskeletal disorders (MSD). The present study investigated the prevalence of MSD among Korean dentists and association between their MSD and physical workload. In addition, detailed causes related to the physical workloads were identified in dental operation, and needs for improvement of dental instrument and environment were collected from Korean dentists. The standardized Nordic questionnaire was used to survey body troubles and three types of questionnaires were made to investigate the physical workloads, causes of the physical workloads and improvement priority of dental equipments, respectively. A total of 104 Korean dentists were participated in the survey. Neck trouble (82%) was the most prevalent in Korean dentists, and shoulder (68%) and low back trouble (56%) followed, while low back trouble was reported to be most frequent in previous studies. The body troubles were related to the physical workload of the corresponding body parts, although they were not associated with personal characteristics. Most Korean dentists selected 'to keep direct view inside patient's mouth' and 'no support of the hand with dental instruments' as the causes of awkward and strenuous work postures. They wanted design improvement for some equipment in their operating room such as operating light and arrangement of workplace.

• 한국ITS학회 논문지
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• 제8권3호
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• pp.71-82
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• 2009

As a solution to spectrum under-utilization problem, Cognitive radio (CR) introduces a dynamic spectrum access technology. In the area, one of the most important problems is how secondary users (SUs) should choose between the available channels, which means how to achieve load balancing between channels. We consider spectrum load balancing problem for CR system in frequency domain and especially in time domain. Our objective is to balance the load among the channels and balance the occupied time length of slots for a fixed channel dynamically in order to obtain a user-optimal solution. In frequency domain, we refer to Dynamic Noncooperative Scheme with Communication (DNCOOPC) used in distributed system and a distributed Dynamic Spectrum Load Balancing algorithm (DSLB) is formed based on DNCOOPC. In time domain, Spectrum Load Balancing method with QoS support is proposed based on Dynamic Feed Back theory and Hash Table (SLBDH). The performance of DSLB and SLBDH are evaluated. In frequency domain, DSLB is more efficient compared with existing Compare_And_Balance (CAB) algorithm and gets more throughput compared with Spectrum Load Balancing (SLB) algorithm. Also, DSLB is a fair scheme for all devices. In time domain, SLBDH is an efficient and precise solution compared with Spectrum Load Smoothing (SLS) method.

• 산업경영시스템학회지
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• 제33권2호
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• pp.33-38
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• 2010

To survive head-to-head competition, we should keep our labor productivities above those of other nations. However, our labor productivities are low compared to those of the developed countries. It is the well-known fact that we make up for the productivities with long work hours. Entering the line of developed nations safely and enjoying well-being age freely, we need to achieve high labor productivities without sacrificing work hours. What would be a fine solution? Back to the basics! Although it is important to enforce R&D on high-tech products, we should have so-called bluebird philosophy, being faithful to the basics and trying to find solutions at a stone's throw. Basics of basics may be unceasing improvement, establishing reasonable standard times, and maintaining them. To support going back to the basics, this thesis proposes VITAMAX, a motion and time study software. As VITAMAX stands for "Visual Improvement and Time Analysis for Maximizing Profits", it provides a simple and powerful visual tool which is useful for improving manual works and determining standard times. Since VITAMAX is based on the Microsoft Excel and VBA, it is very cost-effective and easy to use. VITAMAX may contribute to the profit increase of manufacturing companies, especially for the small and medium-sized enterprise.

• 화약ㆍ발파
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• 제39권3호
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• pp.44-64
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• 2021

4차 산업혁명 시대의 도래와 함께 빅데이터의 활용과 인공지능 기법을 활용한 공학적 응용이 증가하고 있다. 발파 분야에서도 인공지능 기법을 활용한 다양한 연구들이 보고되고 있다. 본 논문에서는 발파분야에서 많이 활용되고 있는 인공신경망, 퍼지 이론, 유전자 알고리즘, 떼 지능, 서포트 벡터머신과 같은 인공지능 기법을 소개하고 이들 기법을 이용한 발파진동, 비석, 암석 파쇄도, 폭풍압, 여굴 예측 기법에 대한 연구들을 조사, 정리하였다. 향후 인공지능 기법을 활용하여 보다 효율적이고 안전한 발파설계, 발파 효율 향상과 발파에 의한 주변 환경에 미치는 영향을 최소화하기 위하기 위한 발전적인 접근 방향에 대한 논의에 활용할 수 있는 기초 자료를 제공하고자 한다.

• PNF and Movement
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• 제11권1호
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• pp.7-16
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• 2013

Purpose : The purpose of this study is to analyze the effect of the proprioceptive exercise program on balance performance in order to the suggest hemiplegic patients the therapeutic intervention. Methods : In this study, Proprioceptive exercise program was applied to 11 hemiplegic patients for 6 weeks as follows: First of all, hemi leg flexion-extension pattern was applied in a supine position. Secondly, alternated leg flexion pattern was applied in a standing posture with one hand support on the unstable platform. Thirdly, rhythmic stabilization techniques were applied in a standing posture on the unstable platform. Results : Significant differences were observed the chronic low back pain patient for VAS, BBS. Chronic low back pain patient improved all test. The results of this study were summarized as follows: 1. After intervention, there was a statistically significant change in the dynamic balance (FSST, TUG, FRT) performance(p<.05). 2. After intervention, there was also a statistically significant change in the static balance (FICSIT-4) performance(p<.05). Conclusion : The result of the study suggests that muscle strength exercise by the intervention of proprioceptive exercise program improves the hemiplegic patients' static and dynamic balance performance.

• Geomechanics and Engineering
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• 제32권6호
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• pp.601-613
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• 2023

Low liquid limit silt, widely distributed in the middle and down reaches of Yellow River, has the disadvantages of poor grading, less clay content and poor colloidal activity. It is very easy to cause vehicle jumping at the bridge-embankment transition section when the low liquid limit silt used as the backfill at the abutment back. In this paper, a series of laboratory tests were carried out to study the physical and mechanical properties of the low liquid limit silt used as back filling. Ground granulated blast furnace slag (GGBFS) was excited by active MgO and hydrated lime to solidify silt as abutment backfill. The optimum ratio of firming agent and the compaction and mechanical properties of reinforced soil were revealed through compaction test and unconfined compressive strength (UCS) test. Scanning electron microscope (SEM) test was used to study the pore characteristics and hydration products of reinforced soil. 6% hydrated lime and alkali activated slag were used to solidify silt and fill the model of subgrade respectively. The pavement settlement regulation and soil internal stress-strain regulation of subgrade with different materials under uniformly distributed load were studied by model experiment. The effect of alkali activated slag curing agent on curing silt was verified. The research results can provide technical support for highway construction in silt area of the Yellow River alluvial plain.

• 여성건강간호학회지
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• 제7권2호
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• pp.188-202
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• 2001

This study was designed to investigate the effect of one-to-one labor support on labor pain, labor stress response, childbirth experience and neonatal status for primipara by a quasi experiment (nonequivalent control group pretest-posttest design), from April 30, 1999 to February 20, 2000. The subjects of this experiment consisted of eighty two primipara with single gestation, full term, uncomplicated pregnancies. Forty one were in the experimental group and forty one in the control group. Their mean age was 25.95 years, their mean gestation period was 39.9 weeks. A caring package of one-to-one labor support had three components. Physical support consisted of massage, back pressure, touch. Emotional support was provided by a continuous nurse's presence, acceptance and encouragement. Informational support involved teaching breathing skills, relaxation skills and knowledge about the labor process. Data assessed labor pain, pulse rate and blood pressure to measure labor stress response. Also, in measuring the value of labor stress response, plasma epinephrine, plasma norepinephrine and serum cortisol were measured. In the 24 hours after birth, the data for the postpartum mother's childbirth experiences was collected. Umbilical cord arterial blood pH, one minute and five minute Apgar score were measured after birth. Data was analyzed by t-test, $x^2$-test, repeated measures ANOVA, ANCOVA with SAS Program. The results were as follows; 1. Labor pain was significantly low in the experimental group(P=.016). 2. No significant group effects were found, but significant time effects were found for plasma epinephrine, norepinephrine, serum cortisol, pulse rate and blood pressure. 3. The childbirth experience of the experimental group was significantly more positive than the control group (P = .005). 4. The umbilical cord arterial blood pH of the experimental group was significantly higher than the control group(P=.014). There was no significant difference between the two groups in neonatal one minute and five minute Apgar scores. In conclusion, these findings indicate that one-to-one labor support could be effective in decreasing labor pain, and increasing positive childbirth experiences, also increasing the neonatal umbilical cord arterial blood pH for primipara. So, one-to-one labor support could be applied as an effective nursing treatment for primipara.

• 한국산업보건학회지
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• 제27권4호
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• pp.352-360
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• 2017

Objectives: 본 연구의 목적은 방문요양 요양보호사들의 세부업무 영역별 특성이 근골격계통증에 미치는 영향을 알아보고, 요양보호사들의 근골격계통증을 경감시키는 방안을 마련하고자 하는 것이다. Methods: 본 연구는 P시에 위치한 C, K 재가센터 소속 요양보호사 192명을 대상으로 실시하였다. 대상자들에게 근골격계통증척도와 요양보호사의 세부업무에 대한 작업부담체크리스트를 작성하게 한 후, 수집된 자료를 SPSS 21.0 프로그램을 이용하여 분석하였다. Results: 요양보호사의 근골격계통증 자각증상 정도를 보면, 허리통증과 어깨통증의 수치가 가장 높았다. 세부업무 영역별 특성이 근골격계통증에 미치는 영향을 알아본 결과, 신체수발영역의 '식사수발하기, 이동지원하기, 목욕지원하기, 체위변경하기, 건강관리영역의 '물리치료보조하기, 욕창관리하기', 시설환경 관리영역의 '청소 및 세탁물관리'가 영향을 미치는 것으로 나타났다. Conclusion: 요양보호사들은 거동이 불편한 대상자들을 이동시키거나 체위를 변경하는 동작 등 신체적으로 무리가 가중되는 환자의 비율이 높아 신체 하중을 가장 많이 받는 허리와, 어깨의 통증을 일으킬 우려가 매우 높다. 이에, 요양보호사들에게 통증이 주로 발생할 수 있는 부위의 과부하를 줄여줄 수 있는 인체역학적 자세에 대한 교육이 필요하다. 그리고 위험한 업무에 대해서는 장비 및 인력의 지원이 제공 되어야 할 것이며, 지속적으로 다각적 차원의 사회적 지원이 필요할 것이다.

• 한국산학기술학회논문지
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• 제12권3호
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• pp.1091-1097
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• 2011

본 논문은 자동차용 시트의 내부에 설치되어 탑승자의 등 부위를 지지하여 편안한 승차감을 제공하는 자동차용 시트의 플라스틱 서스펜션 어셈블리 개발에 관한 것이다. 운전자의 허리를 균등하게 지지하여 주는 구조를 갖도록 설계하고 시트 백 프레임과 플라스틱 서스펜션이 원활하게 조합될 수 있는 구조로 개발하고자 한다. 체압 분포 특성을 고려하여 서스펜션의 단품을 설계하고 기능성을 평가하였다. 또한 실제와 동일한 사이즈의 서스펜션을 모델링하고 구조해석을 수행하였다. 기존 스프링 서스펜션과 새로 개발된 플라스틱 서스펜션의 해석결과 및 실제 측정값이 유사함을 확인하고 최적의 해석 및 설계를 확립하였다.

• 한국터널지하공간학회 논문집
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• 제14권1호
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• pp.37-53
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• 2012

터널 설계 시 사용되는 지반 물성치는 불확실성을 내포한다. 본 연구에서는 최적의 지반물성치를 찾기 위해 터널 계측자료를 활용하여 MATLAB 프로그램의 인공신경망 분석 기능을 이용한 역해석을 수행하였다. 터널 내공변위에 많은 영향을 주는 탄성계수와 측압계수를 변화시켜 총 81개의 학습자료를 구축하였다. 최적의 학습모델을 구축하기 위해 은닉층 수와 노드(node) 수 및 학습율과 관성항을 변화시켜가며 매개변수 연구를 수행하였다. 한편 최적의 학습모델은 평균제곱오차(MSE, Mean Squared Error)와 결정계수($R^2$)를 비교하여 선정되었고, 이를 이용하여 정확한 지층의 탄성계수와 측압계수를 찾았다. 향후 주어진 지반조건에서 최적의 터널 지보패턴을 결정하는 등의 목적으로 본 연구에서 제시된 방법이 적용될 수 있을 것으로 기대된다.