• 한국치위생학회지
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• 제19권5호
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• pp.665-676
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• 2019

Objectives: The purpose of the study was to analyze the association between indirect vision skills and neck, shoulder, and back pain in dental hygienists. Methods: This cross-sectional study included 85 dental hygienists working full-time at dental clinics. A survey was performed for musculoskeletal symptoms in the neck, shoulders, and back of the subjects. The O'Connor tweezer dexterity test was performed using a mirror to evaluate their indirect vision skills. For statistical analyses, the t-test and one-way analysis of variance were performed. Results: The neck was the most common region of musculoskeletal pain (89.4%). The most intense pain was experienced in the neck (70.6%) and right shoulder (60.0%). Neck pain (20.0%) caused the most interference with clinical practice. Indirect vision skills were lower in the group with severe pain in the left shoulder or with high interference in work due to the left shoulder pain (p=0.026 and p= 0.017, respectively) or right shoulder pain (p=0.004). Conclusions: In this study, neck pain was a major musculoskeletal symptom among dental hygienists, and poor indirect vision skills were associated with the development of shoulder pain. Therefore, to prevent such musculoskeletal symptoms, dental hygienists should become proficient in indirect visualization, which enables a balanced and neutral posture.

• The Korean Journal of Pain
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• 제36권1호
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• pp.84-97
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• 2023

Background: The concept of high-impact chronic pain (HICP) has been proposed for patients with chronic pain who have significant limitations in work, social life, and personal care. Recognition of HICP and being able to distinguish patients with HICP from other chronic pain patients who do not have life interference allows the necessary measures to be taken in order to restore the physical and emotional functioning of the affected persons. The aim was to reveal the risk factors and predictors associated with HICP. Methods: Patients with chronic pain without life interference (grade 1 and 2) and patients with HICP were compared. Significant data were evaluated with regression analysis to reveal the associated risk factors. Receiving operating characteristic (ROC) analysis was used to evaluate predictors and present cutoff scores. Results: One thousand and six patients completed the study. From pain related cognitive processes, fear of pain (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.87-0.98; P = 0.007) and helplessness (OR, 1.06; 95% CI, 1.01-1.12; P = 0.018) were found to be risk factors associated with HICP. Predictors of HICP were evaluated by ROC analysis. The highest discrimination value was found for pain intensity (cut-off score > 6.5; 83.8% sensitive; 68.7% specific; area under the curve = 0.823; P < 0.001). Conclusions: This is the first study in our geography to evaluate HICP with measurement tools that evaluate all dimensions of pain. Moreover, it is the first study in the literature to evaluate predictors and cut-off scores using ROC analysis for HICP.

• 한국심리학회지 : 문화 및 사회문제
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• 제22권1호
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• pp.87-118
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• 2016

본 연구는 상사의 비인격적 감독이 상사에 대한 부하의 정서노동에 미치는 영향을 확인하고 이러한 정서노동이 동료들을 향한 대인 일탈행동 및 가정 영역에서의 일-가정 갈등에 어떤 영향을 미치는지 그 과정을 살펴보고자 하는 목적으로 이루어졌다. 또한 비인격적 감독과 부하의 정서노동 간의 관계에서 위계적 조직풍토의 조절효과, 정서노동과 일-가정 갈등, 대인 일탈행동 간의 관계에서 각각 가정지원인식, 조직 내 사회적 네트워크의 조절효과를 검증하고자 했다. 다양한 직종의 현직자들을 대상으로 설문조사를 실시하였으며, 총 291명의 자료가 분석에 사용되었다. 분석 결과, 비인격적 감독을 높게 지각할수록 상사를 향한 부하의 정서노동이 증가함을 확인할 수 있었다. 또한, 비인격적 감독은 상사에 대한 부하의 정서노동이라는 매개과정을 통해 조직 구성원의 일-가정 갈등을 높이고 대인 일탈행동을 증가시킨다는 것이 밝혀졌다. 더불어, 위계적 조직풍토를 높게 지각할 경우 비인격적 감독과 부하의 정서노동 간의 관계가 더 강하게 나타남을 알 수 있었다. 이러한 연구 결과를 토대로 연구의 의의 및 시사점, 그리고 연구가 갖는 한계점과 향후 연구를 위한 제언 등을 통합적으로 논의하였다.

• 항공우주정책ㆍ법학회지
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• 제22권2호
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• pp.27-51
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• 2007

The cumulative result of the work by the ICAO Secretariat, the Secretariat Study Group and the Council Special Group on the Modernization of the Rome Convention of 1952 are two draft Conventions, namely: "Draft Convention on Compensation for Damage Caused by Aircraft to Third Parties, in case of Unlawful Interference", and "Draft Convention on Compensation for Damage Caused by Aircraft to Third Parties" The core provisions of the former draft Convention are as follows: The liability of the operator is strict, that is, without the necessity of proof of fault. It would be liable for damage sustained by third parties on condition only that the damage was caused by an aircraft in flight(Article 3). However, such liability is caped based on the weight of the aircraft(Article 4). It is envisaged to create an independent organization called the Supplementary Compensation Mechanism, with the principle purpose to pay compensation to persons suffering damage in the territory of a State Party, and to provide financial support(Article 8). Compensation shall be paid by the SCM to the extent that the total amount of damages exceeds the Article 4 limits(Article 19). The main issues on the farmer draft Convention are relating to breaking away from Montreal Convention 1999, no limits on individual claims but a global limitation on air carrier liability, insurance coverage, cap of operators' strict liability, and Supplementary Compensation Mechanism. The core provisions of the latter draft Convention are as follows: the liability of the operator is strict, up to a certain threshold tentatively set at 250,000 to 500,000 SDRs. Beyond that, the operator is liable for all damages unless it proves that such damage were not due to its negligence or that the damages were solely due to the negligence of another person(Article 3). The provisions relating to the SCM and compensation thereunder do not operate under this Convention, as the operator is potentially for the full amount of damages caused. The main issues on the latter draft Convention are relating to liability limit of operator, and definition of general risks. In conclusion, we urge ICAO to move forward expeditiously on the draft Convention to establish a third party liability and compensation system that can stand ready to protect both third party victims and the aviation industry before another 9/11-scale event occurs.

• Journal of Hospice and Palliative Care
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• 제4권1호
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• pp.14-25
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• 2001

목적 : 통증에 있어서의 성별차이에 대한 연구결과에 있어서 일치하지 않고 있다. 이에 암환자를 대상으로 성별에 따른 통증정도를 살펴보고, 통증과 우울 및 활동도의 상호작용에 있어서도 성별에 따른 차이가 있는 지를 규명하기 위함이다. 방법 : 1999년 2월부터 6월까지 서울소재 S대학교 병원 혈액종양내과에 입원 또는 외래치료중인 암환자 140명(남성 78명, 여성 62명)을 대상으로 하였으며, 통증정도는 한국판 간이 통증 평가도구(BPI-K), 우울은 한국판 Beck Depression Inventory를 이용한 설문지를 통하여 수집되었고, 기타 인구학적 및 임상학적 자료는 의무기록 열람 및 주치의의 의견을 참조하여 수집되었다. 대상자를 서술하기위해 빈도, 평균, 표준편차를 구하였으며, 집단간 비교에서 불연속척도는chi-square test를 하였고, 연속척도는 t-test를 하였으며, 변인간 상관관계는 Pearson 상관계수를 구하였다. 결과 : 1) 통증의 중증도의 경우 통증정도가 24시간 동안 가장 심했을 때 통증 평균은 남성이 5.77점, 여성이 6.45점이었다. 통증으로 인한 지장정도는 남성의 경우 기분(5.49점), 인생을 즐김(5.36점), 통상적인 일(5.00점)이 순이었으나, 여성의 경우는 통상적인 일(7.48점), 인생을 즐김(7.16점), 기분6.53점) 순이었다. 2) 통증의 중증도의 경우 24시간 동안 평균 통증정도(t=-2.130, P=.035)에서 남성과 여성간에 유의한 차이가 나타났으며, 통증으로 인한 장애정도에서는 활동(t=-2.450, P=.015), 기분(t=-2,321, P=.022), 보행 능력(t=-2.762, P=.007), 통상적인 일(t=-4.946, P=.000), 대인관계(t=-2.595, P=.010), 수면(t=-2.071, P=.040), 인생을 즐김(t=-3.198, P=.001)에서 남성과 여성간에 통계적으로 유의한 차이가 나타났다. 3) 통증과 우울과의 상관관계 분석결과, 통증의 중증도에서 남성의 경우 24시간동안 가장 심했을 때 통증정도와 우울(r=0.323, P<.05), 평균 통증정도와 우울(r=.236, P<.05) 및 조사당시 바로 지금 느끼는 통증정도와 우울(r=0.248, P<.05)이 통계적으로 유의한 정적 상관관계가 나타난 반만 여성에서는 조사당시 바로 지금 느끼는 통증정도와 우울(r=.250, P<.05)만이 유의한 정적상관관계가 나타났다. 통증으로 인한 지장정도의 경우 남성은 모든 항목과 우울간 유의한 정적상관관계가 나타난 반만 여성에서는 전 항목과 우울간에 유의한 관계가 나타나지 않았다. 통증과 활동성 정도와의 상관관계 분석결과, 통증의 중증도에서 남성의 경우 24시간동안 가장 심했을 때 통증정도와 활동성 정도(r=0.378, P<.05), 평균 통증정도와 활동성 정도가(r=.330, P<.05)가 유의한 정적상관관계가 나타난 반면, 여성에서는 활동성 정도와 통증의 중증도는 유의한 관계가 없는 것으로 나타났다. 남성은 관계를 제외한 모든 항목의 통증으로 인한 지장정도와 활동성 정도가 유의한 정적상관관계가 나타난 반만 여성에서는 보행 능력, 통상적인 일, 인생을 즐김 항목과 활동성 정도간 유의한 정적 상관관계가 있었다. 결론 : 암환자의 통증정도 및 지장정도는 여성이 남성보다 높았으며, 통증과 우울 및 활동도와의 상관관계에서 차이를 보였다. 앞으로 암성통증 관리 대책 수립시 여성과 남성의 이러한 차이를 고려하여야 한다.

• 한국안전학회지
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• 제31권5호
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• pp.28-34
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• 2016

When a electric power cable is installed in the air for newly or exchanged working, it is necessary at all time to hold a constant tension for an overhead power cable. And also a pendanted power cable is an extreme job to have work in a high sky. For this reason, the objective of this paper developments working robot for preventing disaster that tension of cable installed automatically power cable to hold a constant. So the working robot works at all the time two tasks for mobil and tension it come into a inference between two tasks, control is difficult. Control methode needs to suppress inference of two tasks. In this paper, for installation of overhead power cable, the scheme and control methode of working robot is presented. the robot work at a same time tow tasks that have hold a constant tension of the power cable and move a constant place while unfasten a winding cable at a drum on a chassis. Working robot consist of three parts with mobile system, tension system and control part. As it is applied the feedback/feedforward control, methode of hybrid control is established to suppress that interference come into between two tasks. The simulation programs is made out using models of mobil and tension system, and a proposed controllers. In accordance with simulation, the model of each systems is discussed to make out proper. And also parameters of controllers is selected a suitable value and the driving performance of robot is evaluated.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권11호
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• pp.532-537
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• 2006

Lightning induced faults accounts for more than 66% at the transmission lines of KEPCO. The lightning causes damages to power system equipments including transmission line, the blackout of electricity and the electro-magnetic interference. Because of this reason, we need the real time lightning information for the optimal operation of power system. And, it is required to obtain and accumulate the lightning current parameters for the insulation design. In 2005, KEPRI constructed a lightning detection network, the KLDNet (i.e. Kepco Lightning Detection & Information System) and launched a lightning information service for KEPCO customers. It is intended to provide data service on the operation of transmission lines and collect lightning-related data, which is the most important factor regulating power system design and operation. The new system will replace LPATS, the old detection system, which has been operating since 1995 and is rapidly failing in terms of both detection performance and location accuracy. The purpose of this paper is to explain the work performed and the results of that work in performing a site survey of several locations. The purpose of the site survey is to find locations acceptable for the installation of a lightning location receiver in support of a Lightning detection system(LDS). A restriction was placed on the surveyed locations, as they must belong to the Korea Electric Power Company. This requirement was made to facilitate the communication needs of the LDS network. Total of 15 sites were evaluated as possible LDS sensor sites. Some of the sites were rejected for physical reasons and therefore no electrical testing was performed. Of the 15 sites, total of 10 sites were considered acceptable and 5 sites were rejected for various reason. In this paper, we would like to explain the site survey and detection efficiency for LDS.

• 대한기계학회논문집A
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• 제21권12호
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• pp.1992-2007
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• 1997

A new algorithm for planning a collision-free path is developed based on linear prametric curve. In this paper robot is assumed to a point, and two linear parametric curve is used to construct a path connecting start and goal point, in which single intermediate connection point between start and goal point is considered. The intermediate connection point is set in polar coordinate(${\theta}{\delta}$) , and the interference between path and obstacle is mapped into CPS(connection point space), which is defined a CWS GM(circular work space geometry mapping). GM of all obstacles in workspace creates overlapping images of obstacle in CPS(Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The empty area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidian Space. A GM based on connection point in elliptic coordinate(${\theta}{\delta}$) is also developed in that the total length of path is depend only on the variable .delta.. Hence in EWS GM(elliptic work space geometry mapping), increasing .delta. and finding the value of .delta. for collision-free path, the shortest path can be searched without carring out whole GM. The GM of obstacles expersses all possible collision-free path as empty spaces in CPS. If there is no empty space available in CPS, it indicates that path planning is not possible with given number of connection points, i.e. path planning is failed, and it is necessary to increase the number of connection point. A general case collision-free path planning is possible by appling GM to configuration space obstacles. Simulation of GM of obstacles in Euclidian space is carried out to measure performance of algorithm and the resulting obstacle images are reported.

• Journal of Communications and Networks
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• 제6권3호
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• pp.216-225
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• 2004

In a cellular network, if there are too many data users in a cell, data may suffer long delay, and system's quality-of-service (QoS) will degrade. Some traditional schemes such as dynamic channel-allocation scheme (DCA) will assign more channels to hot (or overloaded) cells through a central control system (CC) and the throughput increase will be upper bounded by the number of new channels assigned to the cell. In mobile-assisted data forwarding (MADF), we add an ad-hoc overlay to the fixed cellular infrastructure and special channels-called forwarding channels- are used to connect mobile units in a hot cell and its surrounding cold cells without going through the hot cell's base station. Thus, mobile units in a hot cell can forward data to other cold cells to achieve load balancing. Most of the forwarding-channel management work in MADF is done by mobile units themselves in order to relieve the load from the CC. The traffic increase in a certain cell will not be upper bounded by the number of forwarding channels. It can be more if the users in hot cell are significantly far away from one another and these users can use the same forwarding channels to forward data to different cold neighboring cells without interference. We find that, in a system using MADF, under a certain delay requirement, the throughput in a certain cell or for the whole net-work can be greatly improved.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.444-444
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• 2011

Recently, patterned magnetic films and elements attract a wide interest due to their technological potentials in ultrahigh-density magnetic recording and spintronic devices. Among those patterned magnetic structures, magnetic anti-dot patterning induces a strong shape anisotropy in the film, which can control the magnetic properties such as coercivity, permeability, magnetization reversal process, and magneto-resistance. While majority of the previous works have been concentrated on anti-dot arrays with a single magnetic layer, there has been little work on multilayered anti-dot arrays. In this work, we report on study of the magnetic properties of bilayered anti-dot system consisting of upper perforated Co layer of 40 nm and lower continuous Ni layer of 5 nm thick, fabricated by photolithography and wet-etching processes. The magnetic hysteresis (M-H) loops were measured with a superconducting-quantum-interference-device (SQUID) magnetometer (Quantum Design: MPMS). For comparison, investigations on continuous Co thin film and single-layer Co anti-dot arrays were also performed. The magnetic-domain configuration has been measured by using a magnetic force microscope (PSIA: XE-100) equipped with magnetic tips (Nanosensors). An external electromagnet was employed while obtaining the MFM images. The MFM images revealed well-defined periodic domain networks which arise owing to the anisotropies such as magnetic uniaxial anisotropy, configurational anisotropy, etc. The inclusion of holes in a uniform magnetic film and the insertion of a uniform thin Ni layer, drastically affected the coercivity as compared with single Co anti-dot array, without severely affecting the saturation magnetization ($M_s$). The observed changes in the magnetic properties are closely related to the patterning that hinders the domain-wall motion as well as to the magneto-anisotropic bilayer structure.