• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.91-100
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• 2012

Wireless monitoring system for the structural health evaluation has a limit to the reliability of measured response. The objective of this study is to evaluate an effective measurement range of the wireless monitoring system on the analyzed data. For the wireless monitoring system, Bluetooth and Wi-Fi are applied to datalogger-receiver and receiver-personal computer, respectively. For the model of the monopile structure response, a laboratory-scale monopile is manufactured with Mono Cast Nylon and a lateral loading is applied by hammer impacting. Strain gauges attached on the model monopile are connected with the datalogger. The distances of datalogger-receiver and receiver-personal computer are changed for the evaluation of the measurement range. Experimental results show that the receiving rates of the response remain almost constant within limited distance, while the receiving rates dramatically decrease out of effective range. In addition, the receiving rates affect on the measured natural frequencies of the model monopile. This study suggests that the effective range evaluation of the wireless monitoring system may be used for the determination of a monitoring distance to the monopile installed in the offshore wind farm.

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.15-20
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• 2016

In this study we measured a differential ASF to improve the accuracy of time synchronization with the signal transmitted from Pohang 9930M Loran station. We obtained the differential ASF which is calculated from a difference of the TOA measurements between KRISS and Chungnam National University(CNU), and KRISS and National Maritime PNT Office respectively. The TOA measurement at KRISS was measured by UTC(KRIS) reference clock and other sites were measured by atomic clocks respectively. The time variations of differential ASF measurements at CNU and National Maritime PNT Office were within $0.1{\mu}s$ and $0.05{\mu}s$ respectively. And we found the time variations of $0.1{\mu}s$ depending on the surrounding radio-wave environments from the differential ASF measurements of 60 minute moving averages. We can improve the accuracy of time synchronization of the local clock to within 10 ns by compensating the differential ASF through removing the common component of ASF. And we measured the absolute ASF between the Pohang transmit station and KRISS by the measurement technique of absolute time delay using a cesium atomic clock. The average ASF between two points is about $3.5{\mu}s$.

• The KIPS Transactions:PartB
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• v.14B no.3 s.113
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• pp.171-182
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• 2007

We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Then we present a method to eliminate the tracked contour object by replacing with the background scene we get from other frame. First we track the object using LOD (Level-of-Detail) canny edge maps, then we generate background of each image frame and replace the tracked object in a scene by a background image from other frame that is not occluded by the tracked object. Our tracking method is based on level-of-detail (LOD) modified Canny edge maps and graph-based routing operations on the LOD maps. We get more edge pixels along LOD hierarchy. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible. The first frame background scene is determined by camera motion, camera movement between two image frames, and other background scenes are computed from the previous background scenes. The computed background scenes are used to eliminate the tracked object from the scene. In order to remove the tracked object, we generate approximated background for the first frame. Background images for subsequent frames are based on the first frame background or previous frame images. This approach is based on computing camera motion. Our experimental results show that our method works nice for moderate camera movement with small object shape changes.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.79-87
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• 1990

Using Zung's self-rating depression scale, the authors studied depression in 310 elderlies residing in the 9 home for the aged (HFA) in Kyungbuk area, and 234 elderlies living in Taegu city and 107 elderlies attending a Life-long education program in Taegu, which serve as a control group, Community resident elderlies(CRE). The research had been administered during the period from June to August, 1986. The results were as follows : 1. The mean scores of male. female. and the total of the elderlies in HFA were $38.95{\pm}11.55$, $44.18{\pm}14.15$:: and $42.8{\pm}13.7$ respectively while CRE marked $40.8{\pm}11.3$ for male, $45.2{\pm}12.0$ for female, and $43.4{\pm}11.9$ for the total. Therefore there were significant differences between male and female in both groups(p<0.01, p<0.001), though no significant difference between the two groups. However, the depression score of elderlies in HFA might be much higher than that of CRE if 81 elderlies(14.2%) in HFA who had been left out of the statistical evaluation due to their having severe depression, organic brain syndrom, or pseudoementia, etc had been included. 2. The score distribution by items for the elderlies in HFA were from highest scores hopelessness, worthlessness, emptiness, decreased appetite, confusion, while for CRE, hopelessness, decreased appetite, psychomotor retardation, indecisiveness, and worthlessness. Elderlies in HFA showed significantly high scores in depressed mood, weight loss, suicidal rumination(ideation) and psychomotor excitement, while CRE showed significantly high scores in decreased appetite, psychomotor retardation, indecisiveness, and dissatisfaction. 3. Elderlies who scored over 50 numbered 10 males(16%), 57 females(34%), and total of 67(29%) in HFA and 28 males(21%), 77 females(37%), and total of 105(31%) in CRE : female showed higher seores in both groups. 4. Psychosocial factors such as getting older(respectively p<0.01, p<0.01), being Buddhist(respectively p<0.01, p<0.01), and monthly pocket money less than \30,000(respectively p<0.001, p<0.001) were found to have a noticable impact on the depression level of the elderlies in both groups. Factors such as illiteracy (p<0.001, monthly pocket money less than \10,000(p<0.05), and having no family(p<0.01) recorded significantly higher scores among CRE than the elderlies in HFA.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.55-66
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• 1990

This research is focused on the attitudes toward dying and hospice. 4subjects groups are Ca. patient, Ca. patien's family, elderly, medical personnel. A 40 questionare was filled out by each participant. For this study chi-square and T-test was done. The result were as follows : 1. Telling the truth 61.2% of all subject groups agreed upon telling the impending death. About 40% of elderly groups and cancer patient group were disagreed which is the highest percentage in all groups. Particularly medical personnel group were remarkably high in telling the truth. 2. Attitudes of medical personnels 43.3% of all groups agreed upon medical personnels prefer to avoid dying patient. In medical personnel group. 44% of respondents disagred comparably higher than other group. But 37.7% of medical personnel agreed. It showed that medical personnels admitted their negative feelings toward dying patient in considerable degree. 3. Attitudes toward mechanical assistance for life-expanding or hopeless patient. 44.8% of all groups disagreed upon mechanical assistance for hopeless case. Elderly (54.9%) and medical personnels (50%) disagreed, which is higher than cancer patient (33.3%) and (22.8%) of cancer patient's family. 4. Special facility and educational preperation for dying patient. 67.4% of all groups agreed upon the needs of special facility for dying, 81.3% of medical personnels agreed which is highest percentage in all group. 5. Attitudes of family members of dying patient. 82.3% of all groups agreed upon the family members feel annoyed at dying patient. 34% of cancer patient's family member and 48% of cancer patients group agreed, but elderly group showed highest percentage(84%). 6. Perception of dying patient about imminent death. 58.3% of all group thought dying patients are aware of their impanding death even though they had not beent told. 77.3% of medical personnel agreed which is highest percentage in all group.

• Tuberculosis and Respiratory Diseases
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• v.55 no.3
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• pp.280-286
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• 2003

Background : $^{99m}Technetium$ methylene diphosphonates($^{99m}Tc$ MDP) bone scintigraphy is current method of choice for the detection of bone metastases, but whole body $^{18}F$-fluoro-deoxy-D-glucose positron emission tomography($^{18}FDG$ PET) offers superior spatial resolution and improved sensitivity. So we compared whole body $^{18}FDG$ PET with $^{99m}Tc$ MDP bone scintigraphy in patients with skeletal metastases from lung cancer. Patients and Methods : Ninety-two patients with lung cancer taken $^{18}FDG$ PET together with a $^{99m}Tc$ MDP bone scintigraphy within 1 month between March 2000 and March 2003 were investigated retrospectively. Results : The sensitivity, specificity and accuracy of the $^{99m}Tc$ MDP bone scintigraphy versus $^{18}FDG$ PET for the detection of bone metastases in lung cancers were 59% vs 82%, 71% vs 94%, and 68% vs 91%, respectively. In the diagnosis of bone metastases from lung cancer, $^{18}FDG$ PET was statistically superior to $^{99m}Tc$ MDP bone scintigraphy in its specificity and accuracy(p<0.0001). Conclusions : Whole body $^{18}FDG$ PET may be useful in detecting bone metastases among patients with lung cancer.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.77-86
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• 2013

The neuroprotective effects of herbal ethanol extract (GP-EX) from Gynostemma pentaphyllum on dopamine neurons in animal model of Parkinson's disease (PD) were investigated. Rats and mice were administered with rotenone (2.5 mg/kg) for 28 days and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg) for 5 days for the PD models, respectively and the animals were simultaneously treated with GP-EX (30 mg/kg, daily). After preparing the PD models, the animals were also administered with L-DOPA (10 mg/kg) for 14 days with or without GP-EX treatment. Treatment with GP-EX (30 mg/kg) inhibited the rotenone- and MPTP-induced neurotoxic effects in dopamine neurons of rats or mice, which was determined by the numbers of tyrosine hydroxylase-immunohistochemical staining survival cells, as well as the levels of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid. GP-EX (30 mg/kg) also showed the protective effects on neurotoxicity which was induced by long-term administration of L-DOPA (10 mg/kg) in rotenone- and MPTP-induced animal model of PD. The used doses of GP-EX (30 mg/kg) did not produce any signs of toxicity, such as weight loss, diarrhea, or vomiting, in rats and mice during the treatment periods. These results suggest that GP-EX has the protective functions against chronic L-DOPA-induced neurotoxic reactions in dopamine neurons of rotenone- and MPTP-induced animal model of PD. Therefore, the natural GP-EX may be beneficial in the prevention of PD progress and L-DOPA-induced neurotoxicity in PD patients.

• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.41-51
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• 2012

Soils are commonly unsaturated in the near surface. The stiffness of soils is affected by the amount of air and water. The objective of this study is to evaluate the porosity of the unsaturated soils by using the elastic waves including compressional and shear waves. The elastic waves are measured at different degrees of saturation by controlling the matric suction. Thus, the unsaturated soils are characterized at different levels of the matric suction. Shear and compressional waves are measured by using the bender elements and the piezo disk elements, respectively. Both transducers are installed on the walls of the rectangular cell. The unsaturated soils are prepared by using uniform size sands and silts. Test results show that both compressional and shear wave velocities change according to the matric suction. The elastic modulus, the shear modulus, and the Poisson's ratio are estimated based on the measured elastic wave velocities. In addition, the void ratio of the unsaturated soils estimated using elastic wave velocities matches well with the volume based void ratio. This study demonstrates that the elastic waves can be effectively used for the characterization of unsaturated soils.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.882-890
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• 2009

In this paper, we describe a compensation method that can be used for the situation where Loran receivers lose their phase lock to the received Loran signals when Loran signals are employed for the synchronization of national infrastructures such as telecommunication networks, electric power distribution and so on. In losing the phase lock to the received signals in a Loran receiver, the inner oscillator of the receiver starts free-running and the performance of the timing synchronization signals which are locked to the oscillator's phase is very severly degraded, so the timing accuracy under 1 us for a Primary Reference Clock (PRC) required in the International Telecommunications Union (ITU) G.811 standard can not be satisfied in the situation. Therefore, in this paper, we propose a method which can compensate the phase jump by using a compensation algorithm when a Loran receiver loses its phase lock and the performance evaluation of the proposed algorithm is achieved by the Maximum Time Interval Error (MTIE) of the measured data. From the performance evaluation results, it is observed that the requirement under 1 us for a PRC can be easily achieved by using the proposed algorithm showing about 0.6 us with under 30 minutes mean interval of smoothing with 1 hour period when the loss of phase lock occurs.

• Journal of the Korean GEO-environmental Society
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• v.17 no.1
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• pp.49-54
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• 2016

An active layer distributed on surface of an extreme cold region causes a frost heave by repeating the freezing and thawing according to the seasonal temperature change. Since the height of frost heave is greatly affected by the thickness of active layer, an accurate evaluation of the thickness of active layer is necessary for the safe design and construction of the infrastructure in the extreme cold region. In this study, dynamic cone penetrometer, which is miniaturized in-situ penetration device, is applied for the evaluation of active layer depth distribution. As the application tests, two dynamic cone penetration tests were conducted on the study sites located in Solomon and Alaska. In addition, ground temperature variations were obtained. As the results of the application tests, the depth of interface between the active layer and the permafrost was evaluated from the difference in dynamic cone penetration indexes of the active layer and the permafrost, and a layer was detected around the interface considered as an ice lens layer. Also, the interface depths between the above zero and the below zero temperature determined from the ground temperature variations correspond with the interface depths evaluated from the dynamic cone penetration tests. This study demonstrates that the dynamic cone penetrometer may be a useful tool for the evaluation of the active layer in the extreme cold region.