• 한국안광학회지
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• 제17권3호
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• pp.273-278
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• 2012

목적: 20대와 40대 초반 근시안의 성별 및 근시도에 따른 최대조절력의 평균 크기를 비교 분석하여 세대간 조절력의 변화를 알아보고자 하였다. 방법: 20대 초반과 40대 초반의 근시안 각 100명을 대상으로 하여 푸쉬업법(pushup method)을 이용하여 최대조절력을 측정하였다. Hofstetter 공식을 이용하여 얻어진 최대조절력 기대값을 기준으로 기대최소치 미만군(under), 정상군(normal), 기대최대치 초과군(excess)으로 분류하여 비교하였다. 결과: 20대 초반의 평균 조절력은 9.77~11.64 D$(10.77{\pm}2.49D)$, 40대 초반의 평균 조절력은 4.67~6.21 D$(5.34{\pm}1.28D)$로 나타났고, 20대 초반에서 조절력의 기대최소치 미만군은 20%, 정상군 75%, 기대최대치 초과군 5%의 분포를 나타내었고, 40대 초반에서는 조절력의 기대최소치 미만군 18%, 정상군 82%를 나타내었고, 기대최대치 초과군은 나타나지 않았다. 결론: 두 연령층 모두에서 연령이 증가함에 따라 조절력의 감소를 나타내었는데, 근시도와 성별에 따른 유의성은 나타나지 않았다. 또한 각 연령대별로 최대조절력의 기대평균치와 최대조절력 평균의 차를 비교해 보았을 때 20대 초반에서 기대평균치보다 더 작은 것으로 나타나 상대적으로 근업 기회가 많은 20대의 조절력 저하가 훨씬 빨리 나타날 것으로 예상된다.

• 수산해양교육연구
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• 제29권3호
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• pp.811-821
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• 2017

This paper intends to propose the direction for improving the welfare space in crew accommodation of fishing vessels engaged in coastal and inshore fishery business in order to solve the phenomenon which young fishers trend to avoid working on fishing vessels. Coastal and inshore fisheries are defined as permitted fisheries business under the Fisheries Act and classified into coastal fisheries and inshore fisheries based on a gross tonnage of 10 tons. Fisheries Act also stipulates the upper limit tonnage regulation and the restrictions on bottoms of fishing vessels permitted for coastal and inshore fisheries to protect fishery resources and to prevent overfishing. It is difficult to increase the welfare space in crew accommodation of fishers under such restrictions because the welfare space in crew accommodation could be secured by reducing the space for the strength of fishing. Therefore, this paper compares the revision trend of the international convention(The Work in Fishing Convention, 2007) and domestic laws on welfare space in crew accommodation of fishing vessels engaged in coastal and inshore fishery business to find out the problems and improvement points in securing the welfare space in crew accommodation of fishing vessels. As a result, it is proposed to revise the Enforcement Ordinance of the Fisheries Act so as to secure the welfare space in crew accommodation of coastal and inshore fishing vessels within the scope of maintaining the maximum allowable tonnage limit regulation by adding an exemption provisions of the restrictions on bottoms of fishing vessels in which case the gross tonnage is increased for securing the spaces for crew accommodation and sanitary facilities of fishers without increasing net tonnage where the bottoms of fishing vessels is increased by renovating or replacing the fishing vessels bigger than the bottoms of fishing vessels permitted within the scope of maintaining the maximum allowable tonnage limit regulation.

• 한국안광학회지
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• 제12권4호
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• pp.107-110
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• 2007

농촌지역 50대~80대 남녀 137명을 대상으로 자동 안굴절력계에 의한 원용 교정도수 측정, Trial frame와 Trial lens set을 사용한 근용 도수 측정, 최대조절력의 1/2과 2/3를 사용하였을 때의 유효조절력 산정 등을 통하여 조절력을 분석해 보았다. 그 결과 50대에서는 1.84~2.46D, 60대에서는 1.55~2.06D, 70대에서는 1.43~1.90D, 80대에서는 1.22~1.62D로 조사되어 기존에 알려진 나이에 따른 조절력에 비해 다소 높게 나타났다.

• 한국임상보건과학회지
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• 제11권1호
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• pp.1639-1643
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• 2023

Purpose. We wanted to find out how the changes in brain function affected by the beats per minute (BPM) of music affected visual function. Methods. The subjects were 40 people in their 20s (30 men, 10 women) with no eye disease, strabismus, amblyopia and a corrected visual acuity of 1.0 or higher. Wearing headphones while excluding surrounding noise as much as possible, we played music while adjusting the beat rate at 40 BPM intervals from 80 to 200 BPM. Then, pupil size measurement, lag of accommodation test, and minus lens addition method maximum accommodation test were performed and analyzed. Results. As a result of analyzing changes in visual function according to beats per minute [BPM], it was found that although sound can be consciously affected, it does not directly affect visual function significantly in terms of accommodative lag and changes in pupil size. It was confirmed that the effect was limited to the maximum accommodation. Conclusions. In clinical practice, it is necessary to conduct a refraction test while keeping in mind that there are changes in visual function depending on the BPM of surrounding sounds.

• 수산해양기술연구
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• 제48권1호
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• pp.91-98
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• 2012

This study is aimed to utilize a basic data for setting up an allowable air noise with IMO standard in accommodation and working areas of 24m longer fishing vessels. The air noise in accommodation and working areas of 300 tons class squid-jigger were evaluated and the levels were compared to the allowable levels of IMO. The results indicated that the maximum range of noise levels was estimated to be between 54.8dB (A) and 83.2dB, and the correlation between the distance from the main engine to measuring point and the maximum noise level of each point was shown to be y=-13.8log (r)+92.91 ($r^2=0.821$). In addition, except the case of making an accommodation area near to the engine room in 24m longer jigging vessels, it was evaluated that the accommodation noise regulation of 1,600 tons international voyage vessels with 60dB (A) or an improved noise level with 65dB (A) could be properly applied.

• 한국지능시스템학회논문지
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• 제23권1호
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• pp.46-50
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• 2013

본 논문은 다수의 구동기 고장을 가진 유연 관절 로봇의 적응 고장 수용 제어기를 제안한다. 다수의 구동기 고장의 크기와 일어나는 시간은 알려지지 않는다고 가정한다. 구동기 고장을 수용하기 위해 추종 오차의 수렴율과 오버슈트의 최대치로 특성화된 미리 정의된 성능을 보장하는 유계 조건을 갖는 적응 고장 수용 제어기를 설계한다. 르아프노브 안정도 이론을 이용하여 페루트 시스템의 모든 신호가 준 전역적이고 균일하고 궁극적으로 유계됨을 증명하고 추종 오차가 미리 정의된 성능 유계에서 벗어나지 않음을 보인다.

• Journal of the Optical Society of Korea
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• 제15권4호
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• pp.345-351
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• 2011

We present a novel approach to the holographic three-dimensional display using a liquid crystal shutter for binocular display applications. One of the difficult problems in implementing a binocular holographic three-dimensional display is the extremely narrow viewing angle. This problem is attributed to the spatial light modulator pixel number which restricts the maximum spatial bandwidth of the spatial light modulator. In our proposed method, a beam splitter and liquid crystal shutter are used to present two holograms of a three-dimensional scene to the corresponding eyes. The combination of holographic display and liquid crystal shutter can overcome the problem of the extremely narrow viewing angle, presenting threedimensional images to both eyes with correct accommodation depth cues.

• Journal of information and communication convergence engineering
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• 제14권3호
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• pp.191-199
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• 2016

In this study, we investigate the safety requirements and test methods of a radiofrequency stimulator. The main test items include controls of a minimum output, accommodation range, and output parameters that have been known as the safety requirements in conformity with international standards. As the test criteria for controlling the minimum output, an increase or decrease in a unit of 1 mA or 1 V or less was applied to the output amplitude regulator for both continuous and discontinuous control, and the output at the minimum setting was manipulated to not exceed 2% of the maximum setting. For controlling the output parameters, one of the representative test criteria states that the current limit of 250 mA should be equal to or less than 1,500 Hz. Consequently, when applying the radiofrequency stimulator on the human body, we need to ensure that the safety requirements conform to the international standards.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1596-1604
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• 2013

Coordinating operation between large-scale wind power and thermal units in multiple time scale is an important problem to keep power balance, especially for the power grids mainly made up of large coal-fired units. The paper proposes a novel operation mode of multi-scale unit commitment (abbr. UC) that includes mid-term UC and day-ahead UC, which can take full advantage of insufficient flexibility and improve wind power accommodation. First, we introduce the concepts of multi-scale UC and then illustrate the benefits of introducing mid-term UC to the wind-coal intensive grid. The paper then formulates the mid-term UC model, proposes operation performance indices and validates the optimal operation mode by simulation cases. Compared with day-ahead UC only, the multi-scale UC mode could reduce the total generation cost and improve the wind power net benefit by decreasing the coal-fired units' on/off operation. The simulation results also show that the maximum total generation benefit should be pursued rather than the wind power utilization rate in wind-coal intensive system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.307-310
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• 2000

Recently, the demand for the Floating, Production Storage, and Offloading facility(FPSO) which has some economic and technical advantages, has increased in offshore oil production areas. The basic characteristics of a 343,000 DWT class FPSO which is being built in Hyundai Heavy Industries and shall be installed in offshore Angola, is almost same as that of oil carriers. However, she do not have self-propulsion system, but has additional facilities for oil production and positioning system. Main noise source contributing to the cabin noise of the accommodation, are classified into the machine in the engine room and the deckhouse, HVAC system, and the topside equipments. In general, the noise regulation for the offshore structure is much severer than that of the common commercial ships and the maximum acceptable sound pressure level of cabins is specified in 45dB(A). This paper describes the procedure of noise analysis along with its results. Noise analysis has been carried out for the case of emergency diesel generator running condition and the case of normal production condition and the results has been compared with the measurement results of the first case. Based on the results, proper countermeasures to reduce excessive noise level has been applied considering the characteristics of sources and receiver spaces and can be satisfied the specifications at all spaces.