• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.276-282
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• 2012

Vessels receive stress during their navigations as well as during their cargo operations. This stress may cause damages to the hull and may result in accidents. So the hull stress monitoring system(HSMS) is recommended in order to prevent these accidents. In this paper, we manufactured fiber Bragg grating(FBG) sensor and the model ship for towing tank experiments. The strain characteristics of the model ship on the water wave were measured through the towing tank experiment. The FBG sensors and electric strain gauges were attached on the connection jig, and then the characteristics of the FBG sensor were compared with those of the electric strain gauge. The strain of model ship was increased according to the increment of the amplitude of water wave. In particular, the largest strain was measured in the center of the model ship. As the wave period increased, the strain of model ship was decreased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1444-1450
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• 2013

Esophageal stethoscope is used for monitoring the heart sounds and breath sounds of patients during surgery under a general anesthesia. Recently, an electronic esophageal stethoscope (EES)[1] has been developed for the purpose of real-time monitoring these information visually. This system uses only a microphone as the sound sensor. A drawback of the EES system is that it may be difficult to distinguish the first sound ($S_1$) and the second sound ($S_2$) of heart, because their periods are irregular depending on patients. In this paper, we propose an improved EES system in which the infrasound is measured by adding a pressure sensor as well as a sound sensor. We investigate some correlations between the infrasound and characteristics of the heart sound. The proposed system has been tested on 15 patients. The results show that the new system is capable of detecting the first sound more reliably and easily determining the heart rate and breathing period.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.241-243
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• 2014

Recently, as the coastal erosion impacts greats to both social and economical aspects, each local government is trying to setup its countermeasures. However, it is necessary to survey the change of sediment movement characteristics and investigate the continuous environment change by long-term monitoring after building prevention constructions. In this study, predictions on wave deformation and sediment movement deduced through the numerical modeling are made, based on the ordinary and extraordinary wave through seasonal superiority wave direction, height, period and long-term wave characteristics on the eroded beach of central West sea.

• International Journal of Highway Engineering
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• v.18 no.3
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• pp.11-19
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• 2016

PURPOSES : This study supports the evidence that it is possible to rehabilitate a damaged pavement with a lane closure specifically based on the Gimcheon~Sunsan project. METHODS : The prediction results from the simulation programs were compared with field monitoring, which focused on traffic management planning, congestion (length, time, and passing speed), bypass, and user cost, among others. RESULTS : The research results showed that lane closure application and pavement repair of the aged pavement in Korea were possible, even though the prediction results were minimally different from the field monitoring. The road agency contributes to service life extension of the rehabilitated pavement using this method. CONCLUSIONS : A marginal effect caused by the lane closure was observed on travelling users or vehicles, and the user cost of pavement repair decreased. Therefore, introducing the repair method or rehabilitation in Korea is possible. Information dissemination through various media was properly done to execute the project well. Moreover, the construction area traffic utilized nearby alternative roads. Therefore, improving the repaired pavemen's service life while ensuring that the pavement management agency can provide a road with comfortable user riding quality was possible.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.61-69
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• 2008

Land-use in northern Cheongju region is changing rapidly because of the increased interactions of human activities with the environment as population increases. Land-use change detection is considered essential for monitoring the growth of an urban complex. The analysis was undertaken mainly on the basis of the multi-temporal Landsat images (1991, 1992 and 2000) and DEM data in a post-classification analysis with GIS to map land-use distribution and to analyse factors influencing the land-use changes for Cheongju city. The area of each land-use category was also calculated for monitoring land-use changes. Land-use statistics revealed that substantial land-use changes have taken place and that the built-up areas have expanded by about $17.57km^2$ (11.47%) over the study period (1991 - 2000). This study illustrated an increasing trend of urban and barren lands areas with a decreasing trend of agricultural and forest areas. Land-use changes from one category to others have been clearly represented by the NDVI composite images, which were found suitable for delineating the development of urban areas and land use changes in northern Cheongju region. Rapid economic developments together with the increasing population were noted to be the major factors influencing rapid land use changes. Urban expansion has replaced urban and barren lands.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7193-7196
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• 2013

Ovarian cancer patients need a surveillance program for the detection of tumor progression after completion of treatment. The methods generally consist of history taking, physical examination, tumor marker monitoring and imaging. However, the details of recurrence detection with each method are not well defined. To clarify this issue, ovarian cancer patients who achieved complete or partial responses and developed tumor progression at the follow up time between January 2004 and December 2010 in University Hospital Chiang Mai, Thailand, were reviewed. Clinical data, CA 125 level and imaging results at the tumor progression time were recorded and analyzed. There were 144 ovarian cancer patients meeting the inclusion criteria with the mean age of 51 years and 62.5% of them were in an advanced stage. Complete response was achieved in 89 patients (61.8%) after primary treatment. The median progression free survival and overall survival were 15.5 months and 37.5 months, respectively. Abnormal symptoms presented in 49.3% of the studied patients and 59.7% developed physical examination abnormalities. In addition, CA 125 was elevated in 89.6% while in 74.3% of tumor progression was identified by CT-scan. Short treatment time period and a high level of CA 125 were significant independent prognostic factors in these patients. In conclusion, careful history taking, physical examination and monitoring of CA 125 levels are important methods for tumor progression detection in a surveillance program for epithelial ovarian cancer patients.

• Journal of Biomedical Engineering Research
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• v.12 no.4
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• pp.235-242
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• 1991

This research has reported that the selection and assessment of treatment in anxiety disorders depend to a large extend on patient reports of somatic symptomatology. However, the correspondence between such reports and actual physiological data Is unknown as the physiological measures used were taken in laboratory. The purpose of the ambulatory momboring device is, therefore, to present for analysis physiological data derived from the sub jects during their daily activities. The physiological parameters of interest are heart rate, respiratory rate, skin conductance level/response, skin temperature, and activity level. This device had an microcomputer based data acquisition unit, Interfaced to it for the purpose of data collection. The data is collected usually over a period of 12 hours. The data from the ambulatory monitoring device can be used to assess the psychophysiology of anxiety in the field. The data from the device will also reveal if patients who report different sets of symptoms differ physiologically too. Thls will help physicians for the right kind of treatment and also solve the many uncertainties that have existed thus far in quantizing anxiety.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.46-56
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• 2002

The low temperature, low salinity and low density sea water which was originated from the southern part of the Yellow Sea and distributed from the surface to 20 m depth was transported by the northwesterly wind during the period from the middle of March to the beginning of April, 1998 and had an influence on the northern coastal sea area of Cheju Island. Accordingly, this kind of accumulated data may supply the fundamental data for the realtime monitoring of oceanographic conditions and may improve degree of the forecasting accuracy of fishing and oceanographic conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.313-320
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• 2005

Stick-slip friction is one of the material removal mechanisms in tribology. It occurs when the static friction force is larger than the dynamic friction force, and make the friction curve fluctuated. In the friction monitoring of chemical mechanical polishing(CMP), the friction force also vibrates just as stick-slip friction. In this paper, an attempt to show the similarity between stick-slip friction and the friction of CMP was conducted. The prepared hard pa(IC1000/Suba400 stacked/sup TM/) and soft pad(Suba400/sup TM/) were tested with SiO₂ slurry. The friction force was measured by piezoelectric sensor. According to this experiment, it was shown that as the head and table velocity became faster, the stick-slip time shortened because of the change of real contact area. And, the gradient of stick-slip period as a function of head and table speed in soft pad was more precipitous than that of hard one. From these results, it seems that the fluctuating friction force in CMP is stick-slip friction caused by viscoelastic behavior of the pad and the change of real contact area.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.4
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• pp.167-174
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• 2002

This study describes a fetal heart rate(FHR) estimation algorithm using phonogram. Using a phonogram amplifier, various fetal heart sounds are collected in a university hospital. The FHR estimation algorithms consists of a lowpass filter, decimation, envelop detection, pitch detection, and post-processing. The post-processing is the FHR decision procedure using all informations of fetal heart rates. Using the algorithm and other parameters of fetal heart sound, a fetal monitoring software was developed. This can display the original signals, the FFT spectra, FHR and its trajectory. Even though the fetal phonogram amplifier detects the fetal heart sounds well, the sound quality is not so good as the ultrasonography. In case of very week fetal heart sound, autocorrelation of it showed clear periodicity. But two main peaks in one period is an obstacle in pitch detection and peaks are not so vivid. The proposed FHR estimation algorithm showed very accurate and stable results. Since the developed software displays multiple parameters in real time and has convenient functions, it will be useful for the phonogram-style fetal monitoring device.