• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.299-307
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• 2018

Considering a nonlinear high power amplifier(HPA) and a predistorter, we have designed a four-dimensional 8-ary phase shift keying trellis-coded modulation(4D-8PSK-TCM) system, which is recommended for X-band satellite communications. Subsequently, we have evaluated and analyzed the spectrum, constellation characteristics, and BER performance of the system. In satellite communications, owing to the limited power, nonlinear characteristics that determine the operating point of the HPA must be analyzed because the HPA consumes high power. We herein report the design of the 4D-8PSK-TCM system, with efficiencies of 2 and 2.25 bits/channel-symbol. The simulation results confirmed that a 0.35 roll-off value is effective, considering the low peak-to-average power ratio(PAPR) characteristic and the narrow occupation bandwidth of the spectrum. It also confirmed that approximately 15~20 dB of output backoff(OBO) value is required at the HPA when the predistorter is not used, and approximately 1 dB of the OBO value is required when the predistorter is used.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.51-68
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• 2012

This paper aims to investigate the value in culture, history and ecology of the Mt. Palgong. It attempts to build the strategy for making use of The Mt. Palgong by literature survey, interview, and field survey. The main results are as follows: 1) The boundary of physical geography of the Mt. Palgong is classified into two. The boundary of the Mt. Palgong limits to granite mass block in a narrow sense, while in a broad sense, the boundary of the Mt. Palgong includes a contact aureole to be bordered on the Mt. Palgong granite mass block. The boundary from a cultural viewpoint limits to Daegu city(excluding Dalseong county) and Gyeongsan city, Yeongcheon city, Gunwi county and Chilgok (Dongmyeong-myeon, Giseong-myeon) in Gyeongbuk province. 2) In the geological boundary, one of the south-west slope is clearer than that of the north-east slope of the Mt. Palgong. The landforms such as tor, sheeting joint and gutter are well developed as a whole. Mountain landform such as boulder stream, polygonal cracking is relatively well developed on the south-west slope, while river landform is relatively well developed on the north-east slope of the Mt. Palgong. 3) It is necessary to develope various masterpiece of interesting stories related to Mt. Palgong in order to make the Mt. Palgong excellent tour complex. 4) It is desirable to designate the Mt. Palgong as a national park for systematic management. A master plan should be ultimately designed to raise brand value of Daegu city, and make good identity of the city by restoring 'The Mt. Palgong Jecheondan' and registering 'Gatbawi' as world heritage. 5) It is reasonable that the method of development in The Mt. Palgong should be based on the pattern of 'slow life town'. 'The Mt. Palgong museum' will then be designed to give visitors all the informations on The Mt. Palgong.

• Korean Journal of Oriental Medicine
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• v.6 no.1
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• pp.29-46
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• 2000

The clinical application of constitutional Diagnosis is the most important part of Sasang constitutional medicine. It has been studied in various way. The study of morphologic characteristics on the head and face has been identified but didn't considered the Variations of age and sex. For the statistic analysis of the correlation between the sasang constitution and the shape of the face, the head-facial part of 182 cases(the group of throughout the age) and 69 cases(the group of age 30 to 40) were measured by Martin's measurement and analysis of a) the measurement value of height and the component ratio from the Gnathion to each part of face by constitution. b) the measurement value of depth and the component ratio from T-projected to each part of the face by constitution. c) the measurement value of breadth and component ratio between each parts of the facial breadth by constitution. d) the characteristics on each part of face by constitution. e) the result of discriminant analysis about the constitution Authors obtained the results from the study as follows: 1. Taeum-In group is characterized by the value of variables had a tendency to maximum value in throughout the age, the charateristics that the total group show is the shape of face is wide shape in horizontally and flat, the nasal breadth is wider than other constitutions, the lips is narrower than Soyang-In in horizontally and thick shape in vertically, and the biogonial breadth is more developed than other constitutions, so lower face is developed. The charateristics that only the age of 30 40 group show is that the lips is thicker than Soeum-IN. The projection of inter-eyebrows is more projected than Soyang-IN. 2. Soeum-IN group is characterized by the value of variables had a tendency to minimum value in throughout the age. The characteristics that the total group show is the lips is thiner than other constitutions, the breadth of eyes is wider than other constitutions, the difference between sellion and nasal breadth is to be little. The charateristics that only the age of 30 40 group show is that the ratio of upper face in physiognomic face is lager than Soyang-IN. 3. The total age group of Soyang-In is characterized by the shape of face is long in vertically and narrow in horizontally, the total eyebrow breadth and lips and philtrun is wider than other constitutions. The charateristics that only the age of 30 40 group is characterized by the projection of sellion is more projected than Taeum-IN. 4. The values which showed significance in both age group V76, V52, V54, V55, V57, V59, V64, V65, V67, V88, V89, V148, V150, V151, V155, V160, V161, V28, V50, V99, V102, V167, V169, V173, V175, V177, V181 are 27 in all. 5. The values which was significant in the age 30 to 40 group V77, V78, V79, V109, V140, V142, V143, V166, V174 are 9 in all.

• Journal of the Korean housing association
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• v.26 no.2
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• pp.39-46
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• 2015

The 'pathways' in the Deteriorated Residential Area is the valuable place which represents the history of the community. The 'pathways' is the physical boundary which connects individual environment of private residential area to public environment and which has value as a medium for the definite site for regeneration of Deteriorated Residential Area. Thus, the 'pathways' is considered as the perfect material for the public design for spatial culture to regenerate the Deteriorated Residential Area. However, the most of the public design projects utilize the 'pathways' fragmentarily, there are few systematic studies based on the attribute of the Deteriorated Residential Area. The purpose of this study is the consideration on the attributes of the 'pathways', the detection of the spatial characteristics to find application of the 'pathways', and the cultivation of the baseline data for further research for the spatial nature of the Deteriorated Residential Area. For this study, theoretical consideration is practiced in advance to analyze the meaning of the 'pathways' and Deteriorated Residential Area, the case research is performed using design elements as the analytic frame, and the approach is inferred for systematic public design based on the above result. The objects of case research were chosen among the latest projects implemented in the Deteriorated Residential Area whose subject was 'pathways' and which showed successful result. The characteristics of them were investigated and the details were examined through the homepages of the projects, the reports related to the projects, research material, and interview with the people involved. And to conclude, 'pathways' represents the composition of contents, the space of movement, the formation of community, the landscape design, and the participatory design in the Deteriorated Residential Area. The 'pathways' also finds the proper secondary cultural material for the spatial characteristics and can create the space for the various movements, stay, and communication using the characteristics of movements. The narrow and closed space should be utilized actively to be altered into beautiful space and the Deteriorated Residential Area should be regenerated into coexistent design where people share their lives through sharing spaces.

• Journal of Korean Neurosurgical Society
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• v.51 no.5
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• pp.247-252
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• 2012

Objective : The anatomical knowledge is the most important and has a direct link with success of operation in cervical spine surgery. The authors measured various cervical parameters in cadaveric dry bones and compared with previous reported results. Methods : We made 255 dry bones age from 19 to 72 years (mean, 42.3 years) that were obtained from 51 subjects in 100 subjects who donated their bodies. All measurements from C3-C7 levels were made using digital vernier calipers, standard goniometer, and self-made fix tool for two different cervical axes (canal and disc setting). We classified into 4 groups (uncinate process, vertebral body, lamina, and pedicle) and measured independently by two neurosurgeons for 28 parameters. Results : We analyzed 23970 measurements by mean value and standard deviations. In comparing with previous literatures, there are some different results. The mean values for uncinate process (UP) width ranged from 5.5 mm at C4 and 5 to 6.3 mm at C3 and C7 in men. Also, in women, the mean values for UP width ranged from 5.5 mm at C5 to 6.3 mm at C7. C7 was widest and C5 was most narrow than other levels. The antero-posterior length of UP tended to increase gradually from C3 to C6. The tip way, tip distance, and base distance of UP also showed increasing pattern from C3 to C7. Conclusion : These measurements can provide the spinal surgeons with a starting point to address bony architectures surrounding targeted soft tissues for safeguard against unintended damages during cervical operation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7053-7060
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• 2015

In the present work, novel orange peel was extracted with 100%EtOH (ethanol) and fractionated into four fractions namely F1, F2, F3, F4 which were eluted from paper chromatographs using 100%EtOH, 80%EtOH, 50%EtOH and pure water respectively. The crude extract and its four fractions were evaluated for their total polyphenol content (TPC), total flavonoid content (TFC) and radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Their cytotoxic activity using WST assay and DNA damage by agarose gel electrophoresis were also evaluated in a human leukemia HL-60 cell line. The findings revealed that F4 had the highest TPC followed by crude extract, F2, F3 and F1. However, the crude extract had the highest TFC followed by F4, F3, F2, and F1. Depending on the values of $EC_{50}$ and trolox equivalent antioxidant capacity, F4 possessed the strongest antioxidant activity while F1 and F2 displayed weak antioxidant activity. Further, incubation HL-60 cells with extract/fractions for 24h caused an inhibition of cell viability in a concentration-dependent manner. F3 and F4 exhibited a high antiproliferative activity with a narrow range of $IC_{50}$ values ($45.9-48.9{\mu}g/ml$). Crude extract exhibited the weakest antiproliferative activity with an $IC_{50}$ value of $314.89{\mu}g/ml$. Analysis of DNA fragmentation displayed DNA degradation in the form of a smear-type pattern upon agarose gel after incubation of HL-60 cells with F3 and F4 for 6 h. Overall, F3 and F4 appear to be good sources of phytochemicals with antioxidant and potential anticancer activities.

• Journal of the Korean Ceramic Society
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• v.53 no.4
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• pp.400-405
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• 2016

Ferric oxide (${\alpha}-Fe_2O_3$, hematite) is an n-type semiconductor; due to its narrow band gap ($E_g=2.1eV$), it is a highly attractive and desirable material for use in solar hydrogenation by water oxidation. However, the actual conversion efficiency achieved with $Fe_2O_3$ is considerably lower than the theoretical values because the considerably short diffusion length (2-4 nm) of holes in $Fe_2O_3$ induces excessive charge recombination and low absorption. This is a significant hurdle that must be overcome in order to obtain high solar-to-hydrogen conversion efficiency. In consideration of this, it is thought that elemental doping, which may make it possible to enhance the charge transfer at the interface, will have a marked effect in terms of improving the photoactivities of ${\alpha}-Fe_2O_3$ photoanodes. Herein, we report on the synthesis by pulsed electrodeposition of ${\alpha}-Fe_2O_3$-based anodes; we also report on the resulting photoelectrochemical (PEC) properties. We attempted Ti-doping to enhance the PEC properties of ${\alpha}-Fe_2O_3$ anodes. It is revealed that the photocurrent density of a bare ${\alpha}-Fe_2O_3$ anode can be dramatically changed by controlling the condition of the electrodeposition and the concentration of $TiCl_3$. Under optimum conditions, a modified ${\alpha}-Fe_2O_3$ anode exhibits a maximum photocurrent density of $0.4mA/cm^2$ at 1.23 V vs. reversible hydrogen electrode (RHE) under 1.5 G simulated sunlight illumination; this photocurrent density value is about 3 times greater than that of unmodified ${\alpha}-Fe_2O_3$ anodes.

• Korea-Australia Rheology Journal
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• v.17 no.1
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• pp.1-7
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• 2005

Acrylonitrile-Butadiene-Styrene (ABS), polycarbonate (PC) and their alloys are an important class of engineering thermoplastics that are widely used for automotive industry, computer and equipment housings. For the process of recycling mixtures of ABS and PC, it is desirable to know how sensitive the blend properties are to changes in compositions. It was for this reason that blends of virgin ABS and virgin PC at five different compositions, namely, $15\%,\;30\%,\;50\%,\;70%$ and $85\%$ by weight of ABS were prepared and characterised by rheological and mechanical measurements. Rheological properties of these blends in steady, oscillatory and transient step shear and mechanical properties, namely, tensile strength, elongation-at-break and Izod impact strength are reported. The results show that PC behaves in a relatively Newtonian manner, but ABS exhibits significant shear thinning. The ABS-rich blends show a trend that is similar to that of ABS, while PC-rich blends, namely $0\%$ and $15\%$, exhibit a nearly Newtonian behaviour. However, at a fixed shear rate or frequency, the steady shear or the dynamic viscosity varied respectively in a non-mono-tonic manner with composition. Except for $15\%$ blend, the viscosities of other blends fall into a narrow band indicating a wide-operation window of varying blend ratio. The blends exhibited a lower viscosity than either of the two pure components. The other noticeable feature was that the blends at $70\%$ and $85\%$ ABS content had a higher G' than pure ABS, indicating an enhancement of elastic effect. The tensile yield strength of the blends followed the 'rule of mixtures' showing a decreasing value with the increase of ABS content in PC. However, the elongation-at-break and the impact strength did not appear to obey this 'rule of mixtures,' which suggests that morphology of the blends also plays a significant role in determining the properties. Indeed, scanning electron micrographs of the fracture surfaces of the different blends validate this hypothesis, and the $15\%$ blend is seen to have the most distinct morphology and correspondingly different behaviour and properties.

• Journal of Life Science
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• v.13 no.1
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• pp.29-33
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• 2003

The study was conducted to get genetic information on quantitative characters of $F_1$ in barley through diallel crosses using seven malting barley. The results obtained were summarized as follows. Additive, dominant, maternal, and reciprocal effort were observed in culm length, spike length, awn length, culm diameter, grain length, grain width, ]lumber of grains per spike, and 1000 grain weight. Based on the Vr-Wr graphical analysis, culm length, spike length, awn length, grain length, and number of grains per spike were found to be inherited over dominance. Dominant effects were higher than additive effects in culm length, spike length, awn length, culm diameter, grain length, grain width, number of grains per spike, and 1000 grain weight. The narrow- sense heritability showed high value as 40.06% for spike length.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.4
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• pp.78-83
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• 2011

Natural gas is one of the most promising alternatives to gasoline and diesel fuels because of its high thermal efficiency and lower harmful emissions, including $CO_2$. Although the high octane value of natural gas increases engine output and efficiency due to the high compression ratio, this fuel is prone to such difficulties as a narrow limit of inflammability and a slow combustion speed in the lean burn operation domain, leading to unstable combustion and higher emissions of harmful exhaust gases. Hydrogen blended with natural gas can extend the lean burn limit while maintaining stable, efficient combustion and achieving lower NOx, hydrocarbon and green house gas emissions. In this study, the effect of hydrogen addition on an engine performance and NOx emission characteristics was investigated in a heavy duty natural gas engine. The results showed that thermal efficiency was increased and NOx emissions were reduced due to the expansion of lean operation range under stable operation. NOx emission can be significantly reduced with the retard of spark advance timing.