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        검색결과 36

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Limitations of shoulder range of motion (ROM), particularly shoulder internal rotation (SIR), are commonly associated with musculoskeletal disorders in both the general population and athletes. The limitation can result in connective tissue lesions such as superior labrum tears and symptoms such as rotator cuff tears and shoulder impingement syndrome. Maintaining the center of rotation of the glenohumeral joint during SIR can be challenging due to the compensatory scapulothoracic movement and anterior displacement of the humeral head. Therefore, observing the path of the instantaneous center of rotation (PICR) using the olecranon as a marker during SIR may provide valuable insights into understanding the dynamics of the shoulder joint. Objects: The aim of the study was to compare the displacement of the olecranon to measure the rotation control of the humeral head during SIR in individuals with and without restricted SIR ROM. Methods: Twenty-four participants with and without restricted SIR ROM participated in this study. The displacement of olecranon was measured during the shoulder internal rotation control test (SIRCT) using a Kinovea (ver. 0.8.15, Kinovea), the 2-dimensional marker tracking analysis system. An independent t-test was used to compare the horizontal and vertical displacement of the olecranon marker between individuals with and without restricted SIR ROM. The statistical significance was set at p < 0.05. Results: Vertical displacement of the olecranon was significantly greater in the restricted SIR group than in the control group (p < 0.05). However, no significant difference was observed in the horizontal displacement of the olecranon (p > 0.05). Conclusion: The findings of this study indicated that individuals with restricted SIR ROM had significantly greater vertical displacement of the olecranon. The results suggest that the limitation of SIR ROM may lead to difficulty in rotation control of the humeral head.
        4,000원
        2.
        2023.07 구독 인증기관 무료, 개인회원 유료
        This study proposes a new collaborative filtering model that integrates Restricted Boltzmann Machines. The proposed two-stage model is applied to household-level supermarket purchase data. Results show that our model fits the data better and outperforms existing collaborative filtering methods in predicting shopping patterns. The proposed model also improves interpretations of market complexity and common causes of coincidence associated with customers’ multi-category purchases.
        4,000원
        6.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Due to global climate change, mega-droughts have occurred frequently. Since long-term droughts make it difficult to secure the water resources, water supply needs to be restricted in a reasonable manner. In the event of limited water supply, the waterworks need to develop a restricted water supply strategy. This study showed that analyzing daily water supply could be used to respond to the first stage of a drought. According to an analysis of Korea's major water authorities, there was about 7~21% of room for daily minimum water supply in case of a drought. Restricting the water supply by lowering pressure is a good strategy for local water authorities with high water leakage rate since leakage is inversely dependent with pressure. For this method, it is necessary to quantify water deficiency and pressure at each node using a simulation. Since DDA-based software is not possible to predict changes in demand at nodes with pressure reduction, WaterGEMS, a PDA software, was used to quantitatively predict water shortages and pressures at each node. Locations where water is deficient need to install booster pumps or to be dispatched with water tank truck and bottled water. Without these support, lowering pressure could not be an option for water works. This paper suggests a method for waterworks to plan a drought by lowering pressure to restrict water supply using daily water supply analysis and PDA based simulation.
        4,000원
        9.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 시계제한으로 인한 선박 출항통제 해제 후 교통량이 폭주하는 것을 예방하기 위해 현 선박통제규정을 개선하고자 하였다. 평상시의 교통량과 출항통제 해제 후의 교통량를 분석하기 위해 AIS 데이터를 수집하였다. 출항통제 유무에 따른 피크시간 교통량의 차이를 확인하기 위하여 통계검정을 실시하였다. 연구결과 1만톤 미만 그룹에서는 t-test를 실시한 결과, 유의미한 교통량의 차이가 있는 것으로 나타났다. 1만톤 이상 그룹에서는 Mann-Whitney test 결과, 선박 통제 유무에 따른 교통량의 차이가 없는 것으로 나타났다. 출항통제 해제 후 1만톤 미만의 중소형 선박들은 평상시 보다 교통량이 142% 증가하여 1만톤 이상 대형선박과 동시에 출항하게 됨에 따라 교통 폭주를 야기한 것으로 분석되었다. 이러한 교통량 폭주에 따른 선박 충돌사고 개연성을 미연에 방지하고자 현 규정을 길이 160 m 미만 또는 총톤수 1만톤 미만의 선박은 항해 가능하도록 개선할 것을 제언하였다.
        4,000원
        11.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper we have examined the linear stability of triangular equilibrium points in the photogravitational restricted three body problem when both primaries are triaxial rigid bodies, the bigger one an oblate spheroid and source of radiation. The orbits about the Lagrangian equilibrium points are important for scientific investigation. A number of space missions have been completed and some are being proposed by various space agencies. We analyze the periodic motion in the neighbourhood of the Lagrangian equilibrium points as a function of the value of the mass parameter. Periodic orbits of an infinitesimal mass in the vicinity of the equilibrium points are studied analytically and numerically. The linear stability of triangular equilibrium points in the photogravitational restricted three body problem with Poynting- Robertson drag when both primaries are oblate spheroids has been examined by A. Kumar (2007). We have found the equations of motion and triangular equilibrium points for our problem. With the help of the characteristic equation we have discussed stability conditions. Finally, triangular equilibrium points are stable in the linear sense. It is further seen that the triangular points have long or short periodic elliptical orbits in the same range of μ.
        3,000원
        12.
        2015.09 KCI 등재 구독 인증기관·개인회원 무료
        This study deals with the generalization of the Elliptic Restricted Three-Body Problem (ER3BP) by considering the effects of radiation and oblate spheroid primaries. This may illustrate a gas giant exoplanet orbiting its host star with eccentric orbit. In the three dimensional case, this generalization may possess two additional equilibrium points (L6,7, out-of-plane). We determine the existence of L6,7 in ER3BP under the effects of radiation (bigger primary) and oblateness (small primary). We analytically derive the locations of L6;7 and assume initial approximations of (μ-1, ±3A2), where  and A2 are the mass parameter and oblateness factor, respectively. The fixed locations are then determined. Our results show that the locations of L6,7 are periodic and affected by A2 and the radiation factor (q1).
        13.
        2015.09 KCI 등재 구독 인증기관·개인회원 무료
        This work considers the elliptic restricted three-body problem under effects of radiation of the bigger primary, and an oblate spheroid for the smaller primary to mimic an exoplanetary system with a gas giant planet. Under the in uences of both effects we look for the existence of the triangular equilibrium points and the in uences of the radiation and oblateness on the locations and motion of the points. We set the system in a normalized rotating coordinate system and derive equations of motion for the third infinitesimal object. Our study shows that the effects modify the equilateral/isosceles triangle shape with respect to the primaries. The triangular points also have non-planar motion with period depending on the value of the planet oblateness.
        14.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a series of research plan, this study is to provide basic data necessary for the development of fishing industry which will contribute in establishing sound fishing culture in Jeju island through systematic management of fishing, protection of fishery resources and establishment of safety measures for fishermen in accordance with ‘Fishing Management and Support Act’. To attain the proposed objective, this study conducted literature review and surveys on restriction standards of harmful substances generated from fishing equipment and baits, examined the current status of fishing management in popular fishing sites of other cities, and then reviewed and analyzed the fishing management and fishing–restriction zones in Jeju island. The survey on the opinions on the restriction criteria of fishing methods, tools and period, including the acceptable standards for harmful substances showed that general fishermen preferred ‘alleviating the measure (44.8%)’ to ‘aggravating the measure (23.0%)’. Meanwhile, maritime police showed dominant opinion toward ‘aggravating the restriction (52.2%)’ over ‘alleviating the measure (4.3%)’. Furthermore, fishing–related enterprise is favored ‘aggravating the restriction (32.6%)’ over ‘alleviating the measure (27.9%)’. In the survey on the tolerance of fishing baits including criterion for content of certain substance in different types of bait, it showed 57.5% of general fishermen preferred alleviating restriction criteria while 20.7% of them favored tougher restriction. Whereas, 33.3% of maritime police group insisted such fishing baits should be more restricted while 16.7% answered it should be alleviated. 35.9% of fishing–related enterprise was in favor of alleviation while 14.3% preferred aggravation. Upon investigation on the status of fishing management in other cities and towns, it turned out that most of them had safety and convenience facilities, installed warning and guide signs in fishing sites, and set no fishing zones. The review of fishing management and restricted area showed that 10 sites required access restriction and 2 of 10 sites were considered to be partially restricted for weather and season. 82 fishing sites were regarded as unnecessary to be restricted and installation of safety facility and guide signs is necessary for the safety of fishermen.
        4,000원
        15.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the mineral resource protection policies and regulations in production countries of natural resources including rare metals are becoming more stringent. Such environment makes which market has malfunction. In other word, those are not perfect or pure market. Therefore because each market of natural resources have special or unique characters, it is difficult to forecast their market prices. In this study, we constructed several models to estimate prices of natural resources using statistical tools like ARIMA and their business indices. And for examples, Indium and Coal were introduced.
        4,000원
        16.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is one of the research series for providing basic data that would contribute to the development of the field of fishing industry through the systematic fishing management, protection of fishery resources and healthy fishing culture with safety measures for fishermen in Jeju island according to the implementation of 「Fishing Management and Support Act」. As a result of analyzing the related acts, the contents of this study are related with provisions of 「Fishing management and Support Act」 on acts on fishing management, fish bait management, support for fishing and fishing related industries and with provisions of 「Act of the preservation and management of desert island」on the preservation, use and development of desert island (use and development in a desert island, behavior in usable desert island). As a result of the survey, the rocks on the seashore showed the highest popularity with 52.6% for fishermen and the seawall was the highest with 47.1% for Maritime police as their fishing place in the fishing related activity data. And as the survey result about the awareness of 「Fishing management and Support Act」, 65.2% of general fishermen, 36.0% of maritime police and 70.5% of fishing related agencies answered that they knew the act. It was also surveyed whether they consider its contribution to fishing related industry development and positive result was shown by general fishermen and maritime police with 46.8%, 48.0% respectively whereas fishing-related enterprises showed negative answer with 47.7%. In the survey of fishing related regulation standard, general fishermen, maritime police and fishing related agencies all showed different opinions regarding the regulation standard. It is recommended that regulation standard needs to be set up after detailed review.
        4,200원
        17.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The water distribution system should be invariably operated on continuous pattern for 24 hours a day. Occasionally, it is not practically possible to operate for 24 hours due to water shortage or financial constraints. Therefore an intermittent water supply is unavoidable in water shortage area and developing countries.But the intermittent water supply can introduce large pressure forces and rapid fluid accelerations into a water supply network. These disturbances may result in new pipe failure, leakage and secondary contamination.This paper proposed an improvement methodology to prevent the disturbances by intermittent water supply. For the study, the hydraulic variation of intermittent flow in water distribution system was measured and analyzed in the field by comparing with simulation of hydraulic model. Installations of control valves such as, pressure reducing and sustaining and air valves were employed for pressure and flow control. The effectiveness of the methods are presented by comparing hydraulic conditions before and after introducing the proposed solutions.
        4,200원
        18.
        2013.10 구독 인증기관·개인회원 무료
        Recently, the mineral resource protection policies and regulations in production countries of natural resources including rare metals are becoming more stringent. Such environment makes which market has malfunction. In other word, those are not perfect or pure market. Therefore because each market of natural resources have special or unique characters, it is difficult to forecast their market prices. In this study, we constructed several models to estimate prices of natural resources using ARIMA and their business indices. And for examples, Indium and Coal were introduced.
        19.
        2013.04 구독 인증기관·개인회원 무료
        우리나라 전 국토의 6.58%를 차지하고 있는 국립공원은 생태계 현황을 대표하는 지역으로 한국에 서식하는 생물종 39,150종 중 40%에 해당하는 15,727종이 서식하고 있다 (국립공원관리공단, 2012). 특히 환경부에서 지정한 멸종위 기종 221종 중에서 65%에 해당하는 144종이 서식하고 있 어 인간의 간섭 및 개발압력으로부터 마지막 피난처의 중요 한 역할 또한 수행하고 있다. 국립공원은 자연생태계와 자 연 및 문화경관 등을 보전하고 지속가능한 이용을 도모함을 목적으로 하는 자연공원법에 의하여 지정되는 자연공원의 하나로서 자연생태계의 보전뿐만 아니라 지속가능한 이용 또한 고려되어야 한다. 즉, 생물종 서식처의 보존 뿐만 아니 라 탐방객의 이용 또한 고려되어야 하며 이를 위해서는 생 물종의 서식현황 분석은 반드시 선행되어야 할 과제이다. 그러나 생물종이 다양하고 서식처가 광범위하여 종의 전체 적인 서식현황을 분석에는 많은 시간과 비용이 수반된다. 따라서 시간과 공간이 제한되는 산불조심기간 중 산불통제 구간을 대상으로 야생동물의 서식현황을 분석해 보고자 하 였다. 아울러 구례군 지역에 서식하는 야생동물의 서식현황 을 분석하여 보호지역 관리에 기초자료를 제공하고자 하였 다. 월 1회 정기적으로 탐방로를 중심으로 야생동물의 식흔, 배설물 등 흔적을 2010년부터 2012년까지 최근 3년간 모니 터링 하였으며, 모니터링 시 GPS 좌표 측점, 사진촬영, 주변 환경조사 등을 병행하였다. 아울러 무인센서카메라를 10대 설치하여 실체를 확인하였으며, 조사된 자료는 GIS DB로 구축하였다. 최근 3년간, 지리산국립공원 노고단~피아골계곡에서 조 사된 야생동물 흔적은 124건으로 삵 59건, 담비 27건, 족제 비 21건, 멧토끼 10건, 멧돼지 4건, 고라니 2건, 오소리 1건 등이었다. 이중 삵과 담비는 멸종위기종으로서 86건으로 발 견종의 69%를 차지하고 있었다. 특히 봄과 가을철 산불통 제기간 중에는 월평균 19회 관찰되었는데 이는 다른 기간 평균 4회 보다 5배정도 많은 횟수로 탐방객의 출입이 제한 되었을 때 위협요인이 감소됨으로서 서식여건이 보다 안정 화되어 훨씬 많이 발견되고 있음을 알 수 있었다. 2010년부터 2012년 지리산국립공원 구례지역에서 조사 된 야생동물 698건의 서식 분포특성을 분석한 결과 삵 286 건, 담비 139건, 족제비 95건, 수달 53건, 오소리 30건, 멧돼 지 30건, 멧토끼 29건, 너구리 16건, 고라니 13건, 노루 4건, 하늘다람쥐 3건 등이었다. 특히 멸종위기종인 삵, 담비, 수 달, 하늘다람쥐 등이 481건으로 68%를 차지하고 있어 멸종 위기 야생동물의 출현빈도가 매우 높음을 알 수 있었다. 최근 3년간 야생동물 서식현황을 분석한 결과 타기간 보 다 산불방지기간에 출현빈도가 높아 탐방객의 출입에 따른 위협요인을 계량적으로 파악할 수 있었으며, 특히, 봄철 산 불방지기간은 야생동물의 번식기라는 점에서 보다 안정된 서식처를 제공한다는 의의가 있을 수 있다. 또한 멸종위기 종의 흔적이 전체종의 68%가 발견됨으로서 멸종위기종의 서식처를 제공하고 있음을 알 수 있었다. 향후 이러한 결과 를 바탕으로 각 야생동물에 대한 서식처 분석과 더불어 이 를 통한 관리방안이 수립될 필요성이 있다.
        20.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to identify the level of masseter muscle tension according to the levels of restricted movement and pain in the temporomandibular joint(TMJ), thereby verifying the fact that excessive masseter muscle tension can be a cause for restricted movement and pain in the TMJ. The subjects of this study were 81 men and women in their 20s and 30s, who feel uncomfortable with their masticatory function on the preferred chewing side. The subjects were measured in terms of the range of motion (ROM) and deviation of the TMJ and the degree of pain in the affected region. The ROM and deviation of the TMJ were measured using the Global Posture System(GPS) after instructing each subject to open his/her mouth to the fullest and taking photos of the subject with a digital camera. The tension of the masseter muscle was measured with a Pressure Threshold Meter(PTM). After the measurements, in order to compare the ROM of the TMJ, the subjects were divided into two groups based on the ROM of above 35mm and below 35mm. For the deviation and pain, based on the average of total subjects, the subjects were divided into two groups of above and below average. Thereafter, the levels of masseter muscle tension were compared between each pair of groups. According to the results, when each variable was compared between the respective two groups, in terms of the deviation, the pressure pain threshold(PPT) of the masseter muscle revealed a statistically significant difference(p<.05). However, the ROM and pain showed no statistically significant difference. Consequently, masseter muscle tension may cause restricted movement in the TMJ. In particular, the deviation and tension in the masseter muscle is considered to be a factor that causes deviation in the TMJ.
        3,000원
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