• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.207-214
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• 2015

In this paper the independence axiom, one of two principal axioms of axiomatic design theory, is applied to the leveling system development as an design criteria. After functional requirements and corresponding design parameters constitute an initial design matrix for the leveling system, sequence, which is compatible with the independence axiom, of the design parameters of the design matrix is determined and independent components of block leveling system are revealed. As a result of axiomatic design, system configuration related to the design sequence is developed. In order to verify and validate the developed block leveling system, test with real hull block leveling work in site by using total station which is used to acquire three dimensional coordinate of target point is performed. Comparison with measured data and output data from the block leveling system shows the system accuracy is under 1 mm so that the developed system is verified and validated to be used in site.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1943-1950
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• 2015

Korean representative residence type is apartment house. Due to this, civil complaint related to living noise is rapidly increasing. Here, in case when they suffer from surrounding noise in daily life, they can raise civil complaint. However, in general home, it is difficult to measure noise utilizing expert equipment, in many cases they use smart phone app. Noise measurement app that was previously released has markedly low correctness, e.g. value is differently measured in the same condition, therefore, it is difficult to be used for the actual noise measurement. Therefore, this paper suggests mobile data process system for noise measurement of living environment utilizing smart phone. The expected effect of this research can be utilized as the civil complaint material by conveniently measuring the noise and presuming the direction that the noise appeared at the home that has no equipment.

• Economic and Environmental Geology
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• v.37 no.2
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• pp.235-244
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• 2004

The shear strength of deep-sea core sediments from the nofheast equatorial Pacific was measured in various conditions to ensure precision of results. The comparison items were 1) two different measuring systems (hand-held vane and motorized vane), 2) in different places of on-board immediately after collecting the core samples and on-land laboratories after storing these samples for three months in a cold room, 3) two different core samples from a multiple corer within a sampling station, and 4) four different measuring points (holes) from a core sample. In this experiment, the values of shear strength in deep-sea sediments show significant change with depth which increase toward the bottom of core. Also, the results of two cores recovered at the same station indicate that vertical variation of shear strength is mainly caused by the change of physical properties. They strongly support the fact that the difference of vue syrtem and/or experimental conditions are not major factor in the variation of geotechnical properties.

• Journal of Environmental Science International
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• v.15 no.8
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• pp.727-735
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• 2006

In this study, the PHYTO-PAM-fluorometric method was used to evaluate the ETR$_{max}$ in terms of sensitivity to DIN/DIP against 14 microalgae: Prorocentrum micans, Heterocapsa triquetra, Gymnodinium impudicum, Cymnodinium catenatum, Amphidinium caterae, Chlorella vulgaris, Chroococcus minutus, Microcystis aeruginosa, Chlorella ellipsoidea, Nannochloris oculata, Oocystis lacustris, Chroomonas salina, Gloeocystis gigas, and Prymnessium parvum. We found that P. micans, H. triquetra, and A. caterae exposed to the maximum level of DIN/DIP were significantly smaller in the ETR$_{max}$ than that of the minimum and moderate mixture. Unlikely the ETR$_{max}$, the initial slope alpha was not significantly different at the level of 60 DIN/DIP. In G. catenatum, the moderate levels of 15 and 20 in DIN/DIP were found to be significantly different from the ETR$_{max}$ at Chl-Ch4. Gymnodinium impudicum had a higher value than that of the ETR$_{max}$ than that of dinoflagellates used in this study, ranging from 306.1 (Ch4, DIN/DIP: 10) to 520.1 (Ch4, DIN/DIP: 30). The ETR$_{max}$ value obtained from other microalgae was similar to C. impudicum at any of the ratios of DIN/DIP and channels. Consequently, the influence of offshore water current assures us of the suppression of photosynthesis and electron transport rate in dinoflagellates. Gymnodinium impudicum has not been researched in the area of red tides in Korea, but it will be enough to creat the massive algal blooms in the future because of higher potential photochemical availability.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.4
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• pp.441-448
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• 1996

The cyclone/annular denuder system/filter pack sampling system (ADS) was used to collect the acidic air pollutants in Chongju city. The data set was collected on nine different days with 24 hour sampling period from July 27 through August 27, 1995. The chemical species measured were $HNO_3, HNO_2, SO_2 and NH_3$ in the gas phase, and $PM_{2.5}(d_P<2.5 \mum), SO_4^{2-}, NO_3^- and NH_4^+$ in the particulate phase. Mean concentrations measured from this study were: $0.90 \mug/m^3 for HNO_3, 1.27 \mug/m^3 for HNO_2, 10.9 \mug/m^3 for SO_2, 4.82 \mug/m^3 for NH_3, 27.5 \mug/m^3 for PM_{2.5}, 5.24 \mug/m^3 for SO_4^{2-}, 1.22 \mug/m^3 for NO_3^-, and 1.64 \mug/m^3 for NH_4^+$. The fine particle $(PM_{2.5})$ mass measured for the ADS samples was slightly higher than the fine particle mass measured for the corresponding dichotomous sampler. For the wind coming from Chongju industrial complex the concentrations of acidic air pollutants measured were higher when compared with other directions. Specially, $SO_2 and PM_{2.5}$ concentrations for the wind coming from Chongju industrial complex were 3.6 and about 2 times, respectively, higher than those of other wind directions. High correlations were observed between $PM_{2.5} and fine particle's ion components $(r=0.82 with SO_4^{2-}, r=0.76 with NO_3^- and r=0.89 with NH_4^+). NH_4^+ and SO_4^{2-}$ was also highly correlated (r=0.97).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.558-561
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• 2018

Human errors have known as a majority of maritime navigational accidents such as collision and grounding. A large number of relevant research applied indirect research methods such as survey and interview. The research methods are limited to collect objective data regarding human errors due to its nature. Therefore, the purpose of this study is to improve the limitation of human error measurement of navigators by applying wearable sensors. Infrared sensors by using a 3-D printer to accommodate the special environment of a ship were developed for the study. As results, a significant reliance on the Integrated Navigation System including Electronic Chart Display and Information System (ECDIS) and Radar. The results are expected to motivate further research to investigate human errors of ship navigators to reduce the maritime navigational accidents.

• Korean Journal of Optics and Photonics
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• v.8 no.3
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• pp.189-193
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• 1997

Aspheric pick-up lenses are increasingly used in consumer products such as computer and multimedia, as their mass production has become possible owing to the injection molding process. However still much work needs to be done for more effective manufacture of aspheric lenses, one area of which is the in-line inspection of produced lenses. In this paper, we present a lateral-shearing interferometer that has specially been designed to have a high immunity to external vibration and atmospheric disturbance. The interferometer comprises four prisms. They are directly attached to each other using an immersion oil so that relative sliding motions between the prisms are allowed. Their relative displacement can readily generate necessary lateral-shearing and phase-shifting to determine the wavefront of the beam collimated by the lens under inspection. A special phase-measuring algorithm of arbitrary-bucket is adopted to compensate the phase-shifting error caused by the thickness reduction in the immersion oil. Zernike polynomial fitting has done for determinating quantitative aberration of aspheric pick-up lenses. The interferometer built in this work is robust to external mechanical vibration and atmospheric disturbance so that experimental results show that it has a repeatability of less than λ/100.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.174-174
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• 2016

하천은 침식작용과 퇴적작용에 의해 유사를 하류방향으로 이동시킨다. 하천의 침식작용은 하상을 변화시키고 교량, 보 등의 하천 구조물의 안전성을 저해하여 국민의 재산과 생명에 막대한 피해를 입힌다. 또한 퇴적작용은 상류로부터 이동한 유사를 하도 내에 퇴적시켜 하천의 형상을 변화시키고, 통수면적을 감소시켜 홍수기에 범람 빈도와 규모를 증가시킨다. 이처럼 부유사 자료는 하천 구조물의 설계, 수자원 개발 및 관리를 위한 하천계획의 전반에 있어 매우 중요한 자료이지만, 국내의 경우 유사량 측정방법에 대한 연구가 미비하여 대부분 유사량 채집기를 활용한 직접 측정이 이루어지고 있다. 하지만 유사량 채집기를 활용한 관측은 매우 제한된 지역에서 간헐적으로 실시되고 있어 측정 자료가 부족한 실정이다. 이러한 한계를 극복하고자 간접적인 측정 방식을 개발하였으나 우리나라의 강우 특성상 홍수기를 거치면서 하천의 수리학적 특성이 변화하여 관계식의 신뢰도가 떨어지며 자주 갱신해야 한다는 어려움이 있다. 본 연구에서는 횡방향 유속과 신호대잡음비(Signal to Noise Ratio, SNR)를 측정하는 H-ADCP(SonTek, SL-3000)와 레이저 회절을 이용하여 지점의 입도분포와 부유사 농도를 측정하는 레이저부유사측정기(LISST : Laser In-Situ Scattering and Transmissometry)를 이용하여 자료를 취득하였다. 그리고 취득된 신호대잡음비, 부유사 농도간의 관계분석을 통해 회귀식을 구축한 후, 초음파 산란도로 정의되는 신호대잡음비를 활용하여 실내 실험수로의 부유사량을 산정하였고 실측 부유사량과의 비교를 통해 오차 분석을 실시하였다. 오차 분석 결과 실측 부유사량은 138.15g/s, 추정 부유사량은 165.372g/s로 신호대잡음비를 이용하여 추정한 부유사량이 약 19% 과다산정 하는 것으로 나타났다. 본 연구의 결과는 현재 우리나라에 다수 설치되어 있는 수평초음파도플러유속계(H-ADCP)를 활용한 지속적인 부유사량 관측의 토대를 마련할 것으로 사료된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.993-995
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• 2014

Typical dwelling pattern of apartment houses in Korea. Because of this the noise of life problem arise, complaints are surging. In real-life, if suffering is unavoidable due to ambient noise, to handle a civil complaint the using a noise meter. At home, it is difficult to measure the noise using professional equipment. So, many uses smartphone application in general. But released existing noise measurement application has different value from the sensor sensitivity for each smartphone model to same situation. The value is lacks precision and this is not considered as having been made by measuring the actual noise purpose. Therefore in this paper, we propose a mobile data processing system for the living environment of noise measurement using a smartphone. Benefits of this study is to improve the accuracy of noise measurements and to find direction of noise to handle complaints.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.312-315
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• 2014

Smoke generated from business establishments and factories will not only cause air pollution but also have a significant impact on the human body. Generally, the most common method for measuring the turbidity of the plume generated from the stack is a method of observing by the transmissometer mounted in the chimney or Method 9 from the US EPA(Environmental Protection Agency) which is a visual method of determining plume turbid emitted from stationary sources. However, these methods need a lot of cost to build and maintain. In this paper, we build a plume turbidity measurement module programs using light sensing. We design and implement a module which acquires the pictures of the plume using a digital camera and measures the turbidity of it using the DOM(Digital Optical Method). In addition, we demonstrate the excellence by comparing and analyzing implemented module and other methods.