• 산업경영시스템학회지
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• 제24권65호
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• pp.31-40
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• 2001

We Propose an improved shovel design to minimize physical discomfort and the risk of cumulative trauma disorder at shoveling tasks. The specifications of shovels in Korean standard data were scrutinized to check if they met the anthropometric specification of Korean population in 1997. We also applied "Body Map" pictograph and self-conscious checklist to field survey to analyze the discomfort of shoveling task. Thirty male subjects whose age were ranging from 18 to 65 voluntarily participated in the experiment. The measurement results show that shoveling workers were exposed to hazards of CTD's. Especially, when workers were involved in ditch digging and construction their trunk vend more than 120 degree. In order to compare the new designed shovel and the traditional K.S shovel, an analysis of variance was performed and we obtained very strong evidence that the new designed shovel was better in reducing physical discomfort. According to the results from electromyograrn experiment the new shovel contributed to improving subjective comfort level and reducing low back muscle fatigue. For futher study, the research may be extended to determine the relationship among shovel sharpness, type, digging motion and digging force.ing force.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1312-1320
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• 2008

In this paper, we analyzed the error rate performance of convolution coded 16 QAM signal with Optimum Threshold Detection with maximum ratio combining diversity in Rician Fading Environments. The performance of 16-QAM signal with CTD (conventional threshold detection) which employs convolution coding technique was analyzed and the performance improvement of convolution coded 16-QAM signal with OTD (optimum threshold detection) which is varied according to fading parameter "K" and AWGN in Rician Fading channel was simulated. As a result of analysis, it was shown the effect of performance improvement to overcome the environment of mobile radio data communication channel.

• Ocean Science Journal
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• 제42권1호
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• pp.1-8
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• 2007

Acoustic volume backscattering strength data were collected and Conductivity Temperature Depth (CTD) measurements were conducted in the southern Yellow Sea in summer 2005 and 2006. The high temporal and vertical resolution acoustic data measured with a 307 kHz Acoustic Doppler Current Profiler (ADCP) and a 250 kHz acoustic Doppler profile (ADP) had dominant diel variation, which resulted from vertical migration of sound scatterers. Some scatterers congregating in the bottom layer in the daytime migrated upward at dusk, and migrated downward into the bottom layer at dawn. The migration speeds were estimated. More than 33 days data show that the diel migration varies with time. The feature of migration measured with ADCP and ADP is consistent to some extent with what is described in the study on vertical migration of zooplankton in the southern Yellow Sea with conventional net samples.

• Ocean Science Journal
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• 제43권2호
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• pp.81-90
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• 2008

A study of estuarine flows during a neap tide was performed using 13-hour roving acoustic Doppler current profiles (ADCP) and conductivity-temperature-depth (CTD) profiles in the Altamaha River estuary, Georgia, U.S.A. The least-squared harmonic analysis method was used to fit the tidal ($M_2$) component and separate the flow into two components: the tidal and residual ($M_2$-removed) flows. We applied this method to depth-averaged data. Results show that the $M_2$ component demonstrates over 95% of the variability of observation data. As the flow was dominated by the $M_2$ tidal component in a narrow channel, the tidal ellipse distribution was essentially a back-and-forth motion. The amplitude of $M_2$ velocity component increased slightly from the river mouth (0.45 m/sec) to land (0.6 m/sec) and the phase showed fairly constant values in the center of the channel and rapidly decreasing values near the northern and southern shoaling areas. The residual flow and transport calculated from depth-averaged flow shows temporal variability over the tidal time scale. Strong landward flows appeared during slack waters which may be attributed to increased baroclinic forcing when turbulent mixing decreases.

• 한국해양학회지:바다
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• 제13권3호
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• pp.190-199
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• 2008

북동태평양 열대 해양의 해수특성과 해양구조를 파악하기 위하여 2005년 7-8월에 $131.5^{\circ}W$ 관측선에서 관측한 CTD 자료를 분석하였다. 또한 적도 부근 태평양의 해수특성을 전반적으로 이해하기 위하여 서태평양 $137^{\circ}-142^{\circ}E$에서의 CTD 자료도 분석하여 동태평양의 분석 결과와 비교하였다. 여름철 동태평양의 표층수온은 적도반류 해역에서 가장 높았다. 이것은 $28^{\circ}C$ 이상의 고온수가 봄과 여름철에 적도반류를 타고 서태평양으로부터 동태평양으로 이동하여 약 $4^{\circ}-15^{\circ}N$ 사이에서 동서로 연결되기 때문이다. 북적도해류의 표층에 나타나는 저염분 고용존산소의 해수는 동태평양의 파나마만으로부터 서태평양의 필리핀 부근까지 이동하는 저염분수 때문이다. 반면 남적도해류의 표층에 고염분과 저용존산소의 해수가 분포하는 것은 남태평양 아열대 기원의 고염분수가 적도를 넘어 남적도해류 표층의 열대해수(Tropical Water)와 심층의 고염분수를 형성하고 있기 때문이다. 수심 약 500-1500 m 사이의 중층에서는 염분최소층이 분포하는데, $5^{\circ}N$ 이남은 남극중층수(AAIW) 기원의 해수가, $5^{\circ}N$ 이북은 북태평양중층수(NPIW) 기원의 해수가 분포한다. $4^{\circ}-6^{\circ}N$ 해역에서는 직경 약 200 km이며 반시계 방향으로 회전하는 냉수성 소용돌이(cold eddy)가 관측되었다. 서태평양에 비해 동태평양에서 표층수온은 $1^{\circ}C$ 이상 낮았으며 표층염분은 높았다. 적도 부근의 표층 아래에 분포하는 고염분수는 동태평양에서 상대적으로 저염분(약 0.5 psu) 이었고, $14^{\circ}N$ 이남에서 염분최소층의 염분과 밀도는 동태평양에서 높았다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.596-605
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• 1994

An efficient measurement and evaluation system for hand tool tasks will provide a practical solution to the problem of designing and evaluating manual tool tasks in the workplace. Few studies on the biomechanical analysis of hand postures and tool handling tasks exist because of the lack of appropriate measurement techniques for hand force. A measurement system for the finger forces and joint angles for analysis of manual tool handling tasks was developed in this study. The measurement system consists of a force sensing glove made from twelve Force Sensitive Resistors and an angle-measuring glove (Cyberglove$\^$TM/, Virtual technologies) with eighteen joint angle sensors. A biomechanical model of the hand using the data from the measurement system was also developed. Systems of computerized procedures were implemented integrating the hand posture measurement system, biomechanical analysis system, and the task analysis system for manual tool handling tasks. The measurement system was useful in providing the hand force data needed for an existing task analysis system used in CTD risk evaluation. It is expected that the hand posture measurement developed in this study will provide an, efficient and cost-effective solution to task analysis of manual tool handling tasks. These tasks are becoming increasingly important areas of occupational health and safety of the country.

• 한국지구과학회지
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• 제28권5호
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• pp.545-555
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• 2007

Ocean general circulation model developed by GFDL on the basis of MOM4 of FMS are examined and evaluated in order to elucidate the global ocean status. The model employs a tripolar grid system to resolve the Arctic Ocean without polar filtering. The meridional resolution gradually increases from $1/3^{\circ}$ at the equator to $1^{\circ}$ at $30^{\circ}N(S)$. Other horizontal grids have the constant $1^{\circ}$ and vertical grids with 50 levels. The ocean is also coupled to the GFDL sea ice model. It considers tidal effects along with fresh water and chlorophyll concentration. This model is integrated for a 100 year duration with 96 cpu forced by German OMIP and CORE dataset. Levitus, WOA01 climatology, serial CTD observations, WOCE and Argo data are all used for model validation. General features of the world ocean circulation are well simulated except for the western boundary and coastal region where strong advection or fresh water flux are dominant. However, we can find that information concerning chlorophyll and sea ice, newly applied to MOM4 as surface boundary condition, can be used to reduce a model bias near the equatorial and North Pacific ocean.

• 한국지구과학회지
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• 제41권4호
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• pp.356-366
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• 2020

The accuracy of satellite-observed sea surface salinity (SSS) was evaluated in comparison with in-situ salinity measurements from ARGO floats and buoys in the seas around the Korean Peninsula, the northwest Pacific, and the global ocean. Differences in satellite SSS and in-situ measurements (SSS errors) indicated characteristic dependences on geolocation, sea surface temperature (SST), and other oceanic and atmospheric conditions. Overall, the root-mean-square (rms) errors of non-averaged SMOS SSSs ranged from approximately 0.8-1.08 psu for each in-situ salinity dataset consisting of ARGO measurements and non-ARGO data from CTD and buoy measurements in both local seas and the ocean. All SMOS SSSs exhibited characteristic negative bias errors at a range of -0.50- -0.10 psu in the global ocean and the northwest Pacific, respectively. Both rms and bias errors increased to 1.07 psu and -0.17 psu, respectively, in the East Sea. An analysis of the SSS errors indicated dependence on the latitude, SST, and wind speed. The differences of SMOS-derived SSSs from in-situ salinity data tended to be amplified at high latitudes (40-60°N) and high sea water salinity. Wind speeds contributed to the underestimation of SMOS salinity with negative bias compared with in-situ salinity measurements. Continuous and extensive validation of satellite-observed salinity in the local seas around Korea should be further investigated for proper use.

• 한국자기공명학회논문지
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• 제13권2호
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• pp.126-134
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• 2009

UBLCP1 is composed of Ubiquitin Like domain and RNA Polymerase II Phosphatase I domain. Phosphatase domain (25.9KDa) has been cloned into the E.coli using pET32a vector with TEV protease cleavage site and successfully purified as a monomer using affinity chromatography and histidine tag was cleaved with TEV protease for structural studies. Our results indicated that the Phosphatase domain showed well-defined folded structure based on data from one-dimensional and two-dimensional NMR spectroscopy. Data form circular dichroism also suggested that Phosphatase domain consisted of both ${\alpha}$ -helix and ${\beta}$ -sheet. This information will be used for detailed structural study of UBLCP1.

• 한국환경과학회지
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• 제17권12호
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• pp.1353-1361
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• 2008

Quality control of Argo(Array for Real-time Geostrophic Oceanography) data is crucial by reason that salinity measurements are liable to experience some drift and offset due to biofouling, contamination of sensor and wash-out of biocide. The automated Argo real-time quality control has a limit of sorting data quality, so that WJO program is adopted as standardized method of Argo delayed mode quality control (DMQc) in the world that is a precise quality control method. We conducted DMQC on pressure, temperature and salinity measured by Argo floats in the Pacific Ocean including expert evaluation. Particularly, salinity data were corrected using WJO program. 4 salinity profiles of Argo delayed mode were compared with nearby in situ CTD data and other Argo data in deep layer where oceanographic conditions are stable in time and space. The differences of both salinities were lower than target accuracy of Argo. As compared with the difference of salinities before DMQC, those after DMQC decreased by 60-80 percent. Quality of delayed mode salinity data seemed to be improved correcting salinity data suggested by WJO program.