• Journal of Korean Society of Rural Planning
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• v.5 no.1 s.9
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• pp.35-44
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• 1999

The purpose of this study is to find the bi-polar adjectives for rural stream landscape evaluation by the semantic differential scale and to suggest the major determinants of visual preference in rural stream landscapes. For this, the bi-polar adjectives for rural stream landscape evaluation was found by the method of the reliability test, and the spatial image was analyzed by the factor analysis. The level of visual preference was measured by slide simulation test, and these data were analyzed by the multiple regression. The major findings of this study can be summarized as follows : 1) Of the bi-polar adjectives expressing psychological and physical characteristics, the hi-polar adjectives which demonstrated reliability and consistency run as follows : Bi-polar adjectives expressing psychological characteristics : 'calm-bustling', 'unfamiliar-familiar', 'still-active','depressing-brisk', 'discomfortable-comfortable', 'suppressed-free', 'lifeless-living', 'quiet-noisy', 'unpleasant-pleasant'. Bi-polar adjectives expressing physical characteristics : 'artificial-natural', 'narrow-wide', 'rocky-not rocky', 'desolate-fertile', 'dirty-clean', 'enclosed-open', 'flat-steep', 'not gravelly-gravelly', 'thicketed-not thicketed', 'not weedy-weedy'. 2) Two factors, the harmony and the movement, were derived from the factor analysis for the psychological variables. Three factors, the naturalness, the rock, and the vegetation, were derived from the factor analysis for the physical variables. 3) Rural stream landscape types were classified into four types by the multi-dimensional scaling method. Type III, IV obtained higher rank of visual preference and type I, II obtained lower. 4) For all types, the factors determining the level of visual preference were found to be the harmony, the naturalness, and the vegetation. The visual preference determinants of rural stream landscape need to be considered in improving or restoring the rural stream landscapes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.1
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• pp.109-117
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• 2013

Polar codes are the first provable error correcting code achieving the symmetric channel capacity in a wide case of binary input discrete memoryless channel(BI-DMC). However, finite length polar codes have an error floor problem with successive-cancellation list(SCL) decoder. From previous works, we can solve this problem by concatenating CRC(Cyclic Redundancy Check) codes. In this paper we propose to make polar codes having extended-minimum distance from original polar codes without outer codes using correlation with generate matrix of polar codes and that of RM(Reed-Muller) codes. And we compare performance of proposed polar codes with that of polar codes concatenating CRC codes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.45-51
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• 2015

In this paper, we discuss the belief propagation decoding algorithm for polar codes. The performance of Polar codes for shorter lengths is not satisfactory. Motivated by this, we propose a novel technique to improve its performance at short lengths. We showed that the probability of messages passed along the factor graph of polar codes, can be increased by multiplying the current message of nodes with their previous message. This is like a feedback path in which the present signal is updated by multiplying with its previous signal. Thus the experimental results show that performance of belief propagation polar decoder can be improved using this proposed technique. Simulation results in binary-input additive white Gaussian noise channel (BI-AWGNC) show that the proposed belief propagation polar decoder can provide significant gain of 2 dB over the original belief propagation polar decoder with code rate 0.5 and code length 128 at the bit error rate (BER) of $10^{-4}$.

• Membrane and Water Treatment
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• v.6 no.1
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• pp.27-42
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• 2015

In this study, poly (phenylene oxide) (PPO) and poysulfone (PSf) were sulfonated and aminated respectively. Both sulfonated poly (phenylene oxide) (SPPO) and aminated polysulfone (APSf) were characterized via the measurement of FT-IR, swelling degree, ion exchange capacity (IEC), and ion conductivity. Then the surfaces of these membranes were modified by surface fluorination using 2000 ppm $F_2$ gas against $N_2$ gas for 1 h at room temperature. The surface fluorinated SPPO and APSf membranes were characterized again to determine any differences between the pristine and fluorinated membranes. In total, 3 types of bi-polar membranes were prepared by varying the IEC of the APSf and having a fixed value for the IEC of the SPPO. The hypochlorite concentration generated by using the surface fluorinated membranes was dependent on the IEC of the APSf and ranged from 683 to 826 ppm, while there was a considerable improvement in the durability of the surface fluorinated membranes as they remained intact even after operating for 4 h.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.2011-2016
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• 2018

In this study, we have been investigated pin to plate pulsed bi-polar discharges in saline solutions, where bubble generation occurs. We integrate basic I-V-t electrical characteristics with the ICCD shadowgraph images, and finally instant and time averaged I-V waveforms. We observed that the bubble formation phase dynamics is quite different corresponding to the polarity applied to the pin electrode. When the pin electrode is a cathode, the bubble tends to be periodically detached from the pin electrode and the numerous tiny voltage spikes occur related to the electron emission from a pin cathode casing via, we judge from, direct dissociation of water molecules by energetic electrons. On the contrary, the bubble tends to stick to the pin electrode, when the pin electrode is anode; the bubble grows in size throughout the pulse duration. The dynamic electrical characteristics relative to the applied polarity of a pin electrode are presented and discussed by analysis of time averaged I-V waveforms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.134-139
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• 2005

This paper works on the manufacture and performance evaluation of bi-polar power supplied diesinking electrical discharge machine. The design and implementation of diesinking electrical discharge machine consists of two parts which are a polarity voltage controller design and a servo motor controller design and they are verified and manufactured through simulation. The performance of the implemented machine and conventional one were evaluated by comparing its machining speed and roughness of machined surface. Eventually, the designed machine showed improved performance in the speed and the roughness.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.291-293
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• 2003

A semiconductor switch-based fast hi-polar high voltage pulse generator is proposed in this paper The proposed pulse system is made of a thyristor based-rectifier, DC link capacitor, a push-pull resonant inverter, a high voltage transformer. secondary capacitor, a high voltage IGBT & diode stacks, and a variable capacitor. The proposed system makes hi-polar high voltage sinusoidal waveform using resonance between leakage inductance of the transformer and secondary capacitor and transfers energy to output load at maximum of the secondary capacitor voltage. Compared to previous hi-polar high voltage pulse power supply using nonlinear transmission line, the proposed pulse power system using only semiconductor switches has simple structure and gives high efficiency

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.219.1-219
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• 2005

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2002.10a
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• pp.125-134
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• 2002

This is a prospective study in which we evaluate the 5-10 year results of BiPolar shoulder arthroplasty in 64 patients (71 shoulders) with primary glenohumeral osteoarthritis. Fifty two patients (56 shoulders) were followed for greater than 60 months (average 79months)1 and no patients were lost to follow Lip. The average age of the patient at operation was 72.5 years. The UCLA score increased from 10.8 preoperatively to 25,7 postoperatively. The final Constant score in this elderly subset of patients averaged $65\%$ (unadjusted). Eighty seven percent of patients were satisfied with their final result. Excellent pain relief was achieved with a VAS of 2.5 (0=no pain, 15=excruciating pain). Active anterior forward flexion improved from $45^{\circ}$ to $104^{\circ}$. Seventy five percent of patients reveal persisting head-shell motion at an average of 7 years. There were two reoperations because of humeral stem loosening; both stems should have been cemented at the initial arthroplasty. It is demonstrated that BiPolar shoulder arthroplasty is durable over time, with clinical results equivalent to that in the literature when compared with hemiarthroplasty and total shoulder replacement.

• Polymer(Korea)
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• v.39 no.2
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• pp.338-345
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• 2015

Poly(phenylene oxide) (PPO) and polyether imide (PEI) were sulfonated and aminated to create sulfonated poly(phenylene oxide) (SPPO) and aminated polyether imide (APEI), respectively. Characterization of the SPPO and APEI were performed via measurements of FTIR, thermogravimetry (TGA), swelling degree, ion exchange capacity (IEC), and ion conductivity. Next, the surfaces of these membranes were modified by surface fluorination at room temperature. The surface fluorinated SPPO and APEI membranes underwent characterization again for the mentioned measurements to determine any differences. The 3 types of bi-polar membranes were prepared by varying the IEC of the APEI at a fixed SPPO IEC value, which were applied to the low and high NaCl concentration of feed solution at the different current density, respectively. The hypochlorite concentration derived from the surface fluorinated membranes was dependent on the IEC of the APEI and ranged from 491 to 692 ppm at $80mA/m^2$. At low current density of $5mA/m^2$, the hypochlorite concentrations ranged from 18 to 28 ppm for the 4 hrs surface fluorinated membranes and their durability increased greatly.