• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.255-258
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• 2003

Recently, Digital Watermarking is used to authenticate data and to determine whether the data are distorted or not in medical images which is digitalized. The Fourier Mellin method using the Fourier Transform and the Log-Polar coordinate transform gets an invariant feature for RST distortion in images. But there are several problems in the real materialization. Interpolation of the image value should be considered according to the pixel position and so a watermark loss, original image distortion, numerical approximation is happened. Therefore there should be solved to realization of the Fourier Mellin method. Using the Look up table, there reduce the data loss caused by the conversion between Rectangular and Polar coordinate. After diagnose, medical images are transformed the Polar coordinate and taken the Discrete Fourier transform in the center of ROI region. Maintaining the symmetry in Fourier magnitude coefficient, the gaussian distributed random vectors and binary images are embedded in medical images.

• Progress in Superconductivity
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• v.4 no.2
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• pp.132-136
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• 2003

Extremely selective high temperature superconducting (HTS) band -pass filters were developed for the base transceiver station applications of Digital Cellular communication Service (DCS). The filters have a bandwidth of 25 MHz at a center frequency of 834 MHz. There are 12 resonators which have spiral-meander microstrip-line structures in order to reduce far-field radiations with a reasonable tunability. As a result, the size of filters is 5 mm $\times$ 17 mm $\times$ 41 mm. Device characteristics exhibited a low insertion loss of -0.4 dB with a -0.2 dB ripple and a return loss better than -10 dB in the pass-band at 65 K. The out-of-band signals were attenuated better than 60 dB about 3.5 MHz from the lower band edge, and 3.8 MHz from the higher band edge.

• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.947-952
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• 2009

The purpose of this study is to analyze skin wettedness($w$) used as the rate index of thermal comfort, and to evaluate the wear comfort of outdoorwear. Skin wettedness is widely used to express the degree of thermal comfort. If skin wettedness exceeds a certain threshold, the body feels damp and discomfort. An experiment which consisted of rest(30 min), exercise(30 min) and recovery(20 min) periods was administered in a climate chamber with 10 healthy male participants. Two kinds of outdoorwears made of 100% cotton fabrics (Control) and specially engineered fabrics having feature of quick sweat absorbency and high speed drying fabric (Functional) were evaluated in the experiment. The condition of climate chamber was controlled according to the thermal insulation of 4 kinds of experimental ensembles(E1~E4). Total sweat loss, sweat loss absorbed into clothing and skin temperature were measured. Skin wettedness was calculated from the ratio of evaporative rate to the maximal evaporative capacity. Skin wettedness of 'Functional' was lower than 'Control' in the 3 kinds of ensembles(E1, E2, E4) because the materials of 'Functional' were composed of quick sweat absorbency and high speed drying fabrics, water vapour permeability and waterproof fabrics.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1323-1329
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• 2011

The purpose of study was to analyze how the visual information affects balance control of individuals during single leg stance. A total of 27 young normal people (20 males and 7 females, age: $13.7{\pm}2.6$, height: $162.3{\pm}13.2$ cm, weight: $53.9{\pm}13.9$ kg) was voluntarily involved in the experiment. The subjects were requested to maintain balance for 20 seconds with eyes both open and closed on a force plate and then foot ground reaction data were collected for that duration. Results showed that mean velocity of COP in closed eyes condition was larger 1.84 times than that of the open-eyes condition and range of vertical angle was increased approximately one degree in the closed eyes condition. To accomplish a balance, the frequency power in mediolateral and anteroposterior components of the foot-ground reaction force was increased by 1.3~1.4 times. Consequently, visual absence during single leg stance can result in critical loss of balance and lead to instability of body control.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.5
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• pp.63-71
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• 2007

The conversion efficiency, durability and pressure drop of the automotive exhaust catalysts are dependent on the flow distribution within the substrate. Conventional porous medium approaches assuming monolith resistance based on the one-dimensional laminar flow for simulating the flow through the automotive exhaust catalysts over-predict the flow uniformity in the monolith. In this study, additional pressure loss is also considered by accounting for entrance effects due to the oblique flow incident on the front face of monolith as a consequence of flow separation and recirculation within the diffuser. The incorporation of an additional pressure loss improves the predictions for the maximum flow velocity within the substrate. An numerical study has also been conducted for the three-dimensional unsteady incompressible non-reacting flow inside various dual-monolith catalytic converters for the rapid acceleration/deceleration driving.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.28-33
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• 2017

In this study, the composite material of expandable graphite was made to the material development for improving such as a composite material of the sandwich panels or material properties of a fire door and was tested by the ISO 1182, ISO 5660-1(Cone calorimeter Method). For the test, the composite material of expandable graphite, what the expandable graphite ratio was increased by respectively 0g~30g, was classified A1,A2, A3, A4, and made to the test specimens. Through cone calorimeter test, peak heat release rate(HRR) and total heat release(THR), expanded thickness and expansion rate of each composite material of expandable graphite, and fire prone crack and mass loss rate after burning was measured. Thus, the effect of the addition of the expandable graphite and whether is suitable for reference as a fire retardant, was analyzed. Consequently the correlation of THR and fire retardant performance rate was confirmed.

• Asian Journal of Business Environment
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• v.7 no.3
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• pp.17-22
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• 2017

Purpose - Clarifying one of the biggest public Hospital Costs and incomes according to patients' case mix. It leads to prepare financial information about pubic medical tariffs and hospital operational costs. Research design, data, and methodology - This study calculates the costs both, with and without taking into account capital costs. This holds for comparison of hoteling based on case mix in all medical procedures. The checklists were reviewed and filled by reviewing accounting documents of the hospital, warehouse exclusion list, and daily books of laundry and CSR. Data was analyzed descriptively by using Excel. Results - In both cases, the hospital is losing in terms of hoteling. Because the buildings and equipment are new, this loss is not tangible. However, this will be revealed when costs of reconstruction and replacement of equipment. The loss rate per day of hospitalization was 569318 Rials for Coronary Care Unit (CCU), 528171 Rials for Post Intensive Care Unit (Post ICU), 474570 Rials for ICU, 233183 Rials for Post CCU and 204803 for Surgical ward. Conclusions - Income of hoteling was lower than its costs. ANOVA showed a strong relationship between case mix and hospital costs as well as case mix and its income. This suggests that optimal case mix can minimize the costs and maximize income.

• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.952-959
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• 2018

Clustering is one of the most fundamental algorithms in machine learning. The performance of clustering is affected by the distribution of data, and when there are more data or more dimensions, the performance is degraded. For this reason, we use a stacked auto encoder, one of the deep learning algorithms, to reduce the dimension of data which generate a feature vector that best represents the input data. We use k-means, which is a famous algorithm, as a clustering. Sine the feature vector which reduced dimensions are also multi dimensional, we use the Euclidean distance as well as the cosine similarity to increase the performance which calculating the similarity between the center of the cluster and the data as a vector. A deep clustering networks combining a stacked auto encoder and k-means re-trains the networks when the k-means result changes. When re-training the networks, the loss function of the stacked auto encoder and the loss function of the k-means are combined to improve the performance and the stability of the network. Experiments of benchmark image ad document dataset empirically validated the power of the proposed algorithm.

• Journal of Navigation and Port Research
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• v.36 no.1
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• pp.35-41
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• 2012

In this paper, we analyze the current submarine cooling system and study control algorithms for cooling system. Cooling system are installed in the submarine propulsion motor to protect the motor from high-temperature by iron loss and copper loss. The cooling system control the sea water and fresh water pump RPM to keep the motor temperature stable by external environment and motor RPM holding time. The cooling system simulation program is made for checking the cooling performance, and simulation is performed with various control strategy. The results with proposed cooling algorithm is shown to improve the thermal stability and efficiency of cooling system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.563-568
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• 2003

In this paper, a miniaturized parallel coupled bandpass filter using multi-layered LTCC(Low Temperature Co-fired Ceramics) substrate for SOP(System-On-Package) is proposed for applications to wireless communication systems. The fabricated BPF is composed of five 106${\mu}{\textrm}{m}$ thick LTCC layers and its size is 5.24mm x 4.3mm x 0.53 mm. The measured characteristics of the BPF show the center frequency of 5.8GHz, bandwidth of 200MHz, insertion loss of 2.326dB and return loss of 13.679dB. In addition, the attenuation is 28.052dB at 4.7GHz.