• 산업경영시스템학회지
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• 제20권44호
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• pp.323-332
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• 1997

This study evaluated the compression force at the L5/S1 disc using EMG(Electromyography). EMG signals were analyzed under the condition of fixed vertical factor (20Cm∼80Cm), two horizontal factors (35Cm, 55Cm), and two weight factors (10Kg, 25Kg) 2 times per minute for each posture. Also, the result was compared with the compression force of each posture which computated by the equation of NIOSH(National Institute for Occupational Safety and Health) guide to manual lifting(1991). The experimental result show that EMG signals have more an effect on the Weight than the Horizontal factors. Also, there are not significant differences on the analysis result of EMG signals between Health members and not, because the body buildings which doing Health members are not enhanced the motor unit due to the MMH(Manual Material Handing).

• 제어로봇시스템학회논문지
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• 제8권12호
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• pp.1004-1013
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• 2002

A multirate state feedback control (MRSFC) method is proposed for systems sensitive to disturbance and noise based on the multirate estimator design using current estimator. MRSFC updates the controller output slower than the measurement sampling fiequency of system output by a lifting factor $R=T_c/T_s$ The closed-loop MRSFC system is less sensitive to disturbance and noise due to filtering effect than the conventional single-rate control system The multirate estimator gain can be obtained by solving a conventional pole placement problem such that MRSFC has the same spectrum of eigenvalues in the s-plane as the single-rate control. We applied the proposed multirate state feedback controller to a galvanometer servo system Simulation and experimental results show that settling and tracking performances are improved compared with a conventional single-rate pole placement control (PPC).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.473-476
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• 2003

We suggest 2 dimensional Fast Fourier Transform using Polynomial Transform and integer Fast Fourier Transform. Unlike conventional 2D-FFT using the direct quantization of twiddle factor, the suggested 2D-FFT adopts implemented by the lifting so that the suggested 2D-FFT is power adaptable and reversible. Since the suggested FFT performg integer-to-integer mapping, the transform can be implemented by only bit shifts and auditions without multiplications. In addition. polynomial transform severely reduces the multiplications of 2D-FFT. While preserving the reversibility, complexity of this algorithm is shown to be much lower than that of any other algorithms in terms of the numbers of additions and shifts.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.71-72
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• 2016

Most of studies on PC method aim at the structural analysis and development of PC members, and studies on the construction management aspect are insufficient. Therefore, this study tries to investigate 'hallow PC column composite method(HPC composite method)' from the viewpoint of construction management and analyze the construction cost of the composite method. On the assumption that each comparative method was applied to the zone, the difference in construction cost between the two methods was analyzed. As a result, HPC composite method increased the initial investment cost because of its factor technology, but reduced transport cost, lifting cost, and installation cost through lightweight columns. This study analyzed only the difference in construction cost of HPC composite method so that it has the limitation in evaluating its economy. Therefore, to evaluate the economy of HPC composite method, it is considered to research more the construction cost of HPC composite method.

• 대기
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• 제18권4호
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• pp.367-386
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• 2008

The Weather Research and Forecasting (WRF) model was designed to identify the role of the Taebaek Mountains in the occurrence of heavy snowfall in Yeongdong area with a strong northeast wind on January 20-21, 2008. To this end, in addition to the control simulation with the realistic distribution of the Taebaek Mountains, a sensitivity experiment that removed the orography over the Taebaek Mountains was performed. The control simulation results showed that the resulting wind field and precipitation distribution were similar to what were observed. Results from the sensitivity experiment clearly demonstrates the presence of orographic lifting on the windward slope of the mountains. It is concluded that the altitude of the Taebaek Mountains is the main controlling factor in determining the distribution and amount of precipitation in the Yeongdong area for the case of heavy snowfall in January 2008.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.190-190
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• 2000

This paper presents a multirate state feedback control (MRSFC) method for systems sensitive to disturbance and noise based on the multirate estimator design using the current estimator. MRSFC updates the controller output slower than the measurement sampling frequency of system output by a lifting factor R=T$\sub$c//T$\sub$s/. The closed-loop MRSFC system is less sensitive to disturbance and noise due to filtering effect than the conventional single-rate control system. The multirate estimator gain is obtained from solving a conventional pole placement problem such that MRSFC has the same spectrum of eigenvalues in the s-plane as the single-rate control. We applied the proposed multirate state feedback controller to a galvanometer servo system. Simulation and experimental results show that settling and tracking performances are improved compared with a conventional single-rate pole placement control (PPC).

• 한국습지학회지
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• 제5권1호
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• pp.29-40
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• 2003

This study was performed to research the relation between airmass thunderstorm and stability index with 12 years meteorological data(1990~2001) at Busan. Also We used the analysed stability indices from University of Wyoming to consider airmass thunderstorm. The frequency of thunderstorm occurrence during 12 years was 156 days(annual mean 13days). The airmass thunderstorm frequency was 14 days, most of those occurrence were summertime(59%). And occurrence hour of airmass thunderstorm was distributed from 1300LST to 2100LST broadly. The highest forecast index for airmass thunderstorm at Busan was K index, the lowest forecast index was SWEAT index. The forecasting of thunderstorms is based primary on the concepts of conditional instability, convective instability, and forced lifting of air near the surface. Instability is a critical factor in severe weather development. Severe weather stability indices can be a useful tool when applied correctly to a given convective weather situation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.876-881
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• 2003

This study focused on to design and toanalysis of a myoelectronic hand. We considered a low frequency factor in human life and to quantify low frequency which a human body responded to using a 1-axis ant a 3-axis accelerometer. The dynamic myoelectronic hand are important for tasks such a continuous prosthetic control and a EMG signal recognition, which have not been successfully mastered by the most neural approached To control myoelectronic hand, classifying myoelectronic patterns are also important. Experimental results of FEM are 110㎫ on Thumb, 200㎫ on Index finger, 220㎫ on Middle finger 260㎫ on Ring finger and 270㎫ on Little finger. Experimental results of accelerometer are 1.4-0.4(m/s2) ,(5-20(〔Hz〕) in Feeding activity and 0.4-0(m/s2) (0-10〔Hz〕) in Lifting activity. Considering these facts, we suggest a new type myoelectronic hand.

• 한국산업보건학회지
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• 제20권3호
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• pp.139-146
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• 2010

Recent studies suggest that prolonged standing at work is associated with varicose veins (VV). The objective of this study was to analyze the differences of VV risk in terms of work types in casino dealers and hotel service workers. Symptoms of VV were evaluated using a self-reported questionnaire from 2,092 participants, and muscle fatigue in the lower legs were evaluated using surface electromyography. The shift rate of median frequency in Gastrocnemius was -30.0% among the casino dealers working in prolonged static standing posture, and - 14.3% among the casino dealers sitting during working time. After adjusting age, gender, smoking, and family history of VV, the risk ratio of VV was 3.67(95% CI 2.03-6.59) in group I (prolonged standing and occasional walking at work), 6.29(95% CI 3.48-11.35) in group II (prolonged standing, occasional walking and heavy lifting at work), and 8.07(95% CI 4.51-14.43) in groupIII(prolonged static standing at work). In conclusion, prolonged standing at work may be a work related risk factor of VV.

• 한국산업보건학회지
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• 제16권4호
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• pp.385-397
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• 2006

A high prevalence of farmer's work-related musculoskeletal disorders(MSDs) have been reported in precedent studies. To offer the basic data for reducing the melon farmer's MSDs, a questionnaire survey about MSDs symptoms and work loaded body part and video analysis by 3 checklist(REBA, RULA, OWAS) for musculoskeletal risk assessment were carried. 94 melon farmers for this questionnaire and 1 typical farm for risk assessment were participated. A total of 80.9% of the farmers reported musculoskeletal symptoms and 60.6% reported musculoskeletal symptoms over NIOSH standard. The mainly symptom body part is low back, knee and shoulders. Main risk factors in melon farm are awkward postures, heavey/frequent lifting and repetitive hand/arm motions. The high risk tasks induced by video analysis were harvesting, removing the sprouts and covering with rags. These result can be used practically for planning intervention strategy and programs to prevent farmer's MSDs.