• Journal of KIISE:Databases
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• v.35 no.6
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• pp.481-494
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• 2008

In this paper we propose Fourier magnitudes based privacy preserving clustering on time-series data. The previous privacy-preserving method, called DFT coefficient method, has a critical problem in privacy-preservation itself since the original time-series data may be reconstructed from privacy-preserved data. In contrast, the proposed DFT magnitude method has an excellent characteristic that reconstructing the original data is almost impossible since it uses only DFT magnitudes except DFT phases. In this paper, we first explain why the reconstruction is easy in the DFT coefficient method, and why it is difficult in the DFT magnitude method. We then propose a notion of distance-order preservation which can be used both in estimating clustering accuracy and in selecting DFT magnitudes. Degree of distance-order preservation means how many time-series preserve their relative distance orders before and after privacy-preserving. Using this degree of distance-order preservation we present greedy strategies for selecting magnitudes in the DFT magnitude method. That is, those greedy strategies select DFT magnitudes to maximize the degree of distance-order preservation, and eventually we can achieve the relatively high clustering accuracy in the DFT magnitude method. Finally, we empirically show that the degree of distance-order preservation is an excellent measure that well reflects the clustering accuracy. In addition, experimental results show that our greedy strategies of the DFT magnitude method are comparable with the DFT coefficient method in the clustering accuracy. These results indicate that, compared with the DFT coefficient method, our DFT magnitude method provides the excellent degree of privacy-preservation as well as the comparable clustering accuracy.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.203-209
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• 2008

Nowadays the risk of radiation is getting more serious, so we must know the exact dose that was irradiated, Because very high radiation dose is used in radiation therapy field. We used the ionization chamber which measure the radiation dose in this study. We tried to know the incorrect result from the distortion of geometric structure of ionization chamber and we studied how to find the distortion of geometric structure of ionization chamber. We used a radio fluoroscopy to find the wound degree of electrode of ionization chamber and a reconstructed 3D CT image to analyze the wound degree of electrode quantitatively. we measured degree of distortion by comparing with absorbed dose of normal electrode and wound electrode. The comparative result is not absolute dosimetry at specific point but relative dosimetry between thats. We measured 4 MV, 10MV photon with same absorbed dose and dose rate. The degree of distortion of wound electrode was totally $5.5{\sim}7.2%$, and there was no difference between two energies. The variation induced from radiation dose to be irradiated and dose rate, and the degree of distortion from wound direction also was almost similar value. We could find that the geometric structure of ionization chamber that can influence a basic measurement of radiation dose can be changed by old usage and inattention of management in this study, especially winding of electrode can be happened, in radiation therapy field, It is very important to keep precise radiation dose quantitatively.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.173-180
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• 1996

This paper briefly describes the KITSAT-1 and KITSAT-2 spacecrafts and presents the functions, calibration procedures and in-orbit results of the KITSAT-2 analog sun sensors have been flown as an experimental payload for the future mission. We have two constraints in their design: small size and very low power consumption due to the tight mass and power budget of the spacecraft. Two one-dimensional analog sun sensors are mounted on the top facet of the KITSAT-2 spaceraft. Each has $\pm$60 degrees of view angle and they cover 210 degree field of view in total as the 30 degree view angles are overlapped. Only the relative sun angle around the Z-axis (yaw-axis) and the spin rate of the spacecraft can be achieved as the one dimensional sun sensors are used and they are aligned with the Z-axis. The calibration formulae are obtained using the fifth order line fitting algorithm for each sun sensor on the ground and they are applied to the obtained in-orbit data. ASS-1 with silicon solar cells has maximum error of 1.5 degree and ASS-2 with silicon photocells manufactured at KAIST has maximum error of 0.5 degree except near 0 degree of sun ray incident anagle where random reflection of incident sun ray is maximum in orbit. The results are presented in chapter 4. The performance of each sun sensor and the possible mounting errors are stated in chapter 5.

• Journal of Family Relations
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• v.21 no.2
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• pp.25-51
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• 2016

Objectives: This research started with the attempt to comprehend the relationship between household types and psychological stability by linking single-person households to the emotional index "depression." Method: For this purpose, we first compare to see if there is a difference in socio-demographic variables, social relationships, the degree of depression between single households and multi-person households, and to comprehend the relative influence that household types have on depression by taking other factors under consideration. Results: Then based on the results, we compare and analyze the factors that affect the degree of depression on single-person households and multi-person households, respectively. To summarize the results, first of all, residents in single-person households are somewhat older but show lower level of income, education, and health condition compared to peers inmulti-person households. They also had a consistently high level not only in the frequency of contact and emotional connection with families, relatives, and friends, but also in the degree of depression when compared to multi-person households. Secondly, for depression, considering the various factors targeting all the households, the following had a strong influence in the order of "health condition compared to peers," "emotional connection with family," "household types," "emotional connection with colleagues," "frequency of contact with neighbors," "gender," and "age."The degree of depression increases in the following conditions: if the health condition is worse, lower emotional connection with family, single-person household, lower emotional connection with colleagues, lower the frequency of contact with neighbors, female, and older the age. Thirdly, comparing the factors that affect depression by dividing single-person households and multi-person households, "health condition compared to peers" and "emotional connection with family" had the largest effect in common, respectively. In cases of living alone, regardless of other factors, the degree of depression increases with "health condition compared to peers" and "emotional connection with family." Conclusions: On the contrary, in multi-person households, "health condition compared to peers," "emotional connection with family," "emotional connection with colleagues," "income," and "gender" are important.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.74-83
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• 2022

Objective : Oblique lumbar interbody fusion (OLIF) is a surgical technique that utilizes a large interbody cage to indirectly decompress neural elements. The position of the cage relative to the vertebral body could affect the degree of foraminal decompression. Previous studies determined the position of the cage using plain radiographs, with conflicting results regarding the influence of the position of the cage to the degree of neural foramen decompression. Because of the cage obliquity, computed tomography (CT) has better accuracy than plain radiograph for the measurement of the obliquely inserted cage. The objective of this study is to find the correlation between the position of the OLIF cage with the degree of indirect decompression of foraminal stenosis using CT and magnetic resonance imaging (MRI). Methods : We review imaging of 46 patients who underwent OLIF from L2-L5 for 68 levels. Segmental lordosis (SL) was measured in a plain radiograph. The positions of the cage were measured in CT. Spinal canal cross-sectional area (SCSA), and foraminal crosssectional area (FSCA) measurements using MRI were taken into consideration. Results : Patients' mean age was 69.7 years. SL increases 3.0±5.1 degrees. Significant increases in SCSA (33.3%), FCSA (43.7% on the left and 45.0% on the right foramen) were found (p<0.001). Multiple linear regression analysis shows putting the cage in the more posterior position correlated with more increase of FSCA and decreases SL correction. The position of the cage does not affect the degree of the central spinal canal decompression. Obliquity of the cage does not result in different degrees of foraminal decompression between right and left side neural foramen. Conclusion : Cage position near the posterior part of the vertebral body increases the decompression effect of the neural foramen while putting the cage in the more anterior position correlated with increases SL.

• Journal of the Korean Geotechnical Society
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• v.39 no.8
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• pp.29-39
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• 2023

The degree of saturation determines the connectivity of void space and the particle surface. Thus, it greatly affects the electrical conductivity of soils. This study aimed to analyze the electrical conductivities of coarse grains with a high relevance of pore water conduction and fine grains with a high relevance of surface conduction based on the degree of saturation. It also aimed to express the electrical conductivity of unsaturated soils as a combination of surface and pore water conductions using the modified Archie's equation. Samples were prepared in a plastic cell equipped with four electrodes, and the electrical conductivity was measured based on the porosity at various degrees of saturation (40%~100%). The results demonstrate that Archie's equation can be used to express the electrical conductivity of coarse grains, with a saturation exponent of ~1.93 regardless of the pore water conductivity. However, the saturation exponent of fine grains varied considerably with pore water concentration. This variation can be attributed to the relative magnitude of surface conduction with respect to the electrical conductivity of soils at different pore water concentrations. Thus, the degree of saturation has varying effects on pore water conduction and surface conduction. Therefore, different saturation exponents must be used for pore water conduction and surface conduction to predict the electrical conductivity of unsaturated soils using the modified Archie's equation.

• Asian Oncology Nursing
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• v.3 no.2
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• pp.145-154
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• 2003

Purpose: The study was to furnish basic raw materials that evaluate the efficacy of meatal care according to the form and the relative importance of symptom distress which most of cancer sufferers have been experienced. For that, an investigation of five diverse major cancer symptom distress made a comparison between symptom distress and degree of suffering. Method: Study subjects were 138 inpatients with stomach cancer, lung cancer, hepatocellular carcinoma(HCC), large intestine cancer and breast cancer, except those in the terminal-stage, in 'H' university hospital in Seoul and 'K' center in Ilsan gathered from November 20, 2002 to February 20, 2003. To measure the correlation between feeling of discomfort and agony caused by cancer, 5 point scale (from zero to four), stood on the basis of Symptom Distress Scale (SDS, Rodes & Watson, 1987), was used for this study and the Cronbach's coefficient alpha was 0.95. Accumulated data was analyzed with SPSS 10.0 for window, also used by ANOVA and Duncan's Multiple Range Test. Pearson's Correlation Analysis. Results: 1. Symptom distress of cancer patients was noted and defined in their severity-fatigue, anorexia, pain, depression, dyspepsia, changing appearance and nausea. The degree of symptom distress was fatigue, dyspepsia, depression, anorexia, pain, changing appearance and the degree of suffering was nausea, pain, anorexia, dyspepsia, vomiting, breathing difficulty, changing appearance and fatigue. 2. Examining the difference of degree of symptom distress in each cancer cases, it takes the precedence of them. First, in case of stomach cancer, depression, pain, vomiting and nausea were shown in sequence. In case of lung cancer depression, pain, sleeping problem, anxiety, changing appearance, inattentiveness and vomiting were showed in sequence, depression, changing appearance, sleeping problem, pain in case of HCC, depression, pain in case of large intestine cancer and lastly in case of breast cancer changing appearance, depression, pain and anxiety were shown in sequence. The category of the degree of symptom distress that has a signifiant difference was anorexia, activity discomfort, fatigue, constipation or diarrhea, breathing difficulty, dyspepsia, caughing, fever or chillness, scotoma and urinary disorder. Verifying the highest degree of symptom distress in each cancer cases, anorexia was 1.94(F=4.00, p<.01) in stomach cancer, activity discomfort was 0.97(F=3.08, p<.01) in lung cancer and HCC, fatigue was 2.32(F=4.64, p<.01) in HCC, constipation or diarrhea was 1.83(F=22.31, p<.001) in large intestine cancer, breathing difficulty was 1.83(F=4.00, p<.01) in lung cancer, dyspepsia was 2.69(F=9.98, p<.001) in stomach cancer, coughing was 1.53(F=20.49, p<.001) in lung cancer, fever or chillness was 1.23(F=6.88, p<.001) in lung cancer, scotoma was 1.20(F=3.02, p<.05) in lung cancer and urinary disorder was 1.54(F=11.56, p<.001) in HCC. 3. Examining the difference degree of suffering on cancer cases, the result was as follows; depression of lung cancer was 1.17(F=3.76, p<.01), anorexia of stomach cancer was 1.61(F=3.89, p<.01), constipation or diarrhea of large intestine cancer was 1.42(F=10.43, p<.001), changing appearance of breast cancer was 1.65(F=5.43, p<.001), breathing difficulty of lung cancer was 2.27(F=18.57, p<.001), dyspepsia of stomach cancer was 1.97(F=13.56, p<.001), coughing of lung cancer was 1.70(F=22.07, p<.001), fever or chillness of lung cancer was 1.13(F=4.41, p<.01), scotoma of lung cancer was 0.87(F=3.34, p<.05), anxiety of lung cancer was 0.87(F=4.50, p<.001) and urinary disorder of HCC was 1.43(F=16.71, p<.001). 4. In consequence, comparing between symptom distress and degree of suffering on cancer patients undergoing chemotherapy, lung cancer patients showed the highest feeling of discomfort following stomach cancer, HCC, breast cancer and large intestine cancer(F=2.88, p<.05). On those undergoing radiotherapy, lung cancer, HCC, breast cancer, large intestine cancer was in sequence(F=3.78, p<.05) and those resisting radiotherapy, lung cancer, HCC, stomach cancer, large intestine cancer and breast cancer was in sequence(F=2.72, p<.05). 5. Correlation between symptom distress and degree of suffering on cancer patients was generally significant. Conclusion: this study not only defines a significant correlation between symptom distress and degree of suffering but also proffers basic data to evaluate the efficient meatal care depending upon diverse spectrums of symptom distress and degree of suffering.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.157-161
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• 2003

Proline is known as an osmoprotectant accumulating in response to salt and dehydration stresses. An increased level of proline is achieved by either an induced synthesis or a reduced degradation of proline. In an attempt to increase salt tolerance in carrot, a P5CS gene from mothbean was introduced via an Agrobacterium-mediated transformation. The resulting carrot cells and the regenerated plants containing the transgene showed increased levels of proline compared to nontransgenics. The transgenic cell line, Pj2 showed about 6 times increased degree of tolerance determined by relative growth after a treatment in 250 mM NaCl. In facts, due to the retarded growth shown in non-saline condition, Pj2 cells grow only about 1.2 times better than nontransgenic control under salt stress condition. Taken together, it appears that a P5CS is a key enzyme in proline biosynthesis and the increased accumulation of proline by overexpression of the enzyme is enough to enhance tolerance to salt stress in carrot.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.320-323
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• 1998

Lysozyme was covalentyl conjugated with galactomannan through a amino-carbonyl reaction between the lysine $\varepsilon$-amino groups of lysozyme and the reducing ends of galactomannan at a relative humidity of 79% and 6$0^{\circ}C$. The resulting lysozyme-galactomannan conjugate (LGC) was investigated for its antibacterial activity against Escherichia coli. Lysozyme alone did not exhibit antibacterial activity against E. coli. in contrast , significant bactericidal effect was observed for LGC, depending on the reaction temperature. The degree of conjugation between lysozyme and galactomannan was dependent on the incubation time, which affected the antibacterial efficiency against E. coli. This study demonstrated that the amino-carbonyl reaction between lysozyme and galactomannan could be a potential tool to modify lysozyme toward broadening its antibacterial spectrum to Gram-negative bacteria.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1256-1263
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• 2004

Output feedback passivation problem is studied when the given system is not minimum-phase or does not have relative degree one. Using a parallel connection with an additional dynamics, the authors provide a dynamic output feedback control law which renders the composite system passive. Sufficient conditions are presented under which the composite system is output feedback passive. As an application of the dynamic passivation scheme, a point-to-point control law for a flexible joint robot is presented when only the position measurements are available. This provides an alternative way of replacing the role of the velocity measurements for the proportional-derivative (PD) feedback law. The performance of the proposed control law is illustrated in the simulation studies of a manipulator with three revolute elastic joints.