• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.12
• /
• pp.59-64
• /
• 2009

In this paper, the design of a new bandstop filter with an ultra-wide stopband is proposed using the metamaterial CRLH-TL. Instead of conventional periodic structures and multi-staged CRLH-TLs, extremely small one-cell type is adopted to circumvent the setbacks of conventional filters such as the lengthened ${\lambda}_g/2$-resonator ones or alternating impedance lowpass filter, and relatively slow skirt. Besides, for a very broad stopband, a strong coupling structure including stepped impedances is suggested and the zero-order resonance is made for effective size-reduction. The validity of the proposed design is proven through the fabrication and measurement, showing the overall size less than ${\lambda}_g/10$, the stopband wider than 12 GHz, 0.7 dB of the insertion loss.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.1
• /
• pp.73-77
• /
• 2012

In this article, we designed a wide bandpass filter in order to apply microwave reflectometry for KSTAR. The proposed wide bandpass filter consists of a metamaterial structure which is to get a wide band, a lower insertion loss, and a high skirt. This is applied to VCO's output to enhance the linearity. A pass band is 18-28 GHz and the out of pass band is stopped over 20 dB. To confirm of the metamaterial, we suggest a dispersion diagram. The proposed filter in lower band and upper band of pass band is respectively a left handed and right handed characteristics. A group delay is below 0.5 ns.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.1
• /
• pp.30-38
• /
• 2015

In this paper, the design of a compact triple-mode bandpass filter using a high-Q cylindrical dielectric resonator is proposed. In detail, the triple $TE_{01{\delta}}$ modes along three orthogonal axes are used and novel coupling structure in the metallic enclosure is adopted to introduce the coupling between the resonant modes. Due to the cross coupling, the proposed bandpass filter has an asymmetric frequency response with flexible three transmission zeros, one of which can be located very close to the passband edge to provide an extremely sharp skirt characteristic with low insertion loss. The proposed filter is about 60 % miniaturized compared with conventional single-mode dielectric resonator filter. The proposed bandpass filter design is validated by the circuit and 3D EM simulations and measurements compared to the target specifications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.12
• /
• pp.1447-1453
• /
• 2010

In this paper, the design and the fabrication of dual-band bandpass filter using two dual-mode resonators is presented. Dual-mode resonator using a short stub is miniaturized by inter-digital capacitor and stepped impedance. Two dual mode resonators are designed to have different resonant frequencies, one for the lower passband and the other for the upper passband. Transmission zero is positioned at low or high rejection bands with a sharp skirt characteristic. Dual-band operation can be achieved using dual feeding structure. For WLAN, the proposed filter at 2.45/5.25 GHz is designed and fabricated. The size of the filter is as compact as 1$10.83\;mm{\times}5.3\;mm$.

• Nuclear Engineering and Technology
• /
• v.52 no.12
• /
• pp.2743-2759
• /
• 2020

A detailed computational fluid dynamics (CFD) simulation analysis model was developed using ANSYS CFX 16.1 and analyzed to simulate the basic design and internal flow characteristics of a 180 MW small modular reactor (SMR) with a natural circulation flow system. To analyze the natural circulation phenomena without a pump for the initial flow generation inside the reactor, the flow characteristics were evaluated for each output assuming various initial powers relative to the critical condition. The eddy phenomenon and the flow imbalance phenomenon at each output were confirmed, and a flow leveling structure under the core was proposed for an optimization of the internal natural circulation flow. In the steady-state analysis, the temperature distribution and heat transfer speed at each position considering an increase in the output power of the core were calculated, and the conceptual design of the SMR had a sufficient thermal margin (31.4 K). A transient model with the output ranging from 0% to 100% was analyzed, and the obtained values were close to the T_hot and T_cold temperature difference value estimated in the conceptual design of the SMR. The K-factor was calculated from the flow analysis data of the CFX model and applied to an analysis model in RELAP5/MOD3.3, the optimal analysis system code for nuclear power plants. The CFX analysis results and RELAP analysis results were evaluated in terms of the internal flow characteristics per core output. The two codes, which model the same nuclear power plant, have different flow analysis schemes but can be used complementarily. In particular, it will be useful to carry out detailed studies of the timing of the steam generator intervention when an SMR is activated. The thermal and hydraulic characteristics of the models that applied porous media to the core & steam generators and the models that embodied the entire detail shape were compared and analyzed. Although there were differences in the ability to analyze detailed flow characteristics at some low powers, it was confirmed that there was no significant difference in the thermal hydraulic characteristics' analysis of the SMR system's conceptual design.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.2
• /
• pp.194-201
• /
• 2010

We propose a frequency selective surface(FSS) using double split ring resonators(DSRRs) for isolation enhancement between CDMA and RFID. The structure consists of an outer SRR and an inner SRR, and the gaps are formed in the same direction. By properly adjusting the gap and line width, the resonant frequency and skirt characteristics can be adjusted without varying the unit cell size. The proposed structure has a different field distribution from that of an ordinary SRR for magneto-dielectric materials. One layer consists of $9{\times}9$ unit cells and the other layer was separated by 50 mm. To validate the simulation results, we fabricated the patch antenna and the FSSs, and the measured results show a good agreement with the simulated ones. The electrical size of the unit cell is $0.110\;{\lambda}{\times}0.110\;{\lambda}{\times}0.002\;{\lambda}$, and the size of the two layer FSS is $1.058\;{\lambda}{\times}1.058\;{\lambda}{\times}0.153\;{\lambda}$. The two layer FSS maintain gain in CDMA frequency and has 6.9 dB reduced gain in RFID frequency.

• Journal of the Korean Home Economics Association
• /
• v.41 no.2
• /
• pp.123-139
• /
• 2003

This study examines the characteristics of 45 sects of seven new aboriginal religious groups in Korea including Jeungsan sect, Tangun sect, Soowoon sect, Won Buddhism, Bongnam sect, Gahksedo sect, Shamanism sect through field study and various documents. The purpose of the study is to elucidate how their religious ideas are reflected in their ceremonial costumes and what characteritics and underlying meanings these costumes have, and I reached the following conclusions 1. The new religious groups in Korea modified or mixed the designs or names of existing outfits to convey their ideas or beliefs in their costumes. 2. The costumes of new religious groups turned out to have certain characteristics in common: they all reflected the times, Korean tradition, ancestor worship. 3. I looked at the symbolicity, names, and types of the outfit, and their color scheme to establish their structural characteristics, and it turned out that they an symbolized the creeds and ideas of each religion. The names of the costumes such as Way-Robe, Law-Robe, and Ceremony-Robe, for instance, had to do with Buddhism Taoism, and Confucianism. The most common type of costume consisted of traditional hanbok top, pant, robe, and some type of headpiece for men, and hanbok top and, skirt for women, and if women were to wear a robe, it usually meant the sect believed in sexual equality. There was also a tendency to simplify or minimize the dress code, which seems to indicate that the sect was trying to adapt itself to, the times. The most common type of the outer garment for men was a robe with narrow sleeves, straight lapel, and no slits, and a robe with wide sleeves, straight lapel, and slits for women. The color scheme of the costumes included blue, white, yellow, red, and black, reflecting the influence of the Yin-Yang and Five Elements idea and traditional preference for white of Koreans. 4. These religious costumes were worn at various ceremonies, ritual, and various anniversary services for the master and other dignitaries of the sect to render greater piety to those gatherings, to distinguish the sect from other religious groups, to clarify the meaning of the ceremony, and to heighten the devout feelings of the participants. Thus, the structure (the symbolicity, names, and types of the outfit, and their color scheme) and religious background of the costumes of the new aboriginal religious groups in Korea turned out to have inherited and mixed various element of traditional Korean outfit and those of existing religions to symbolize their religious ideas. Many religions in and fall, and each has its own dress codes, and I hope this study provides a framework and data for other researchers and leaders of new religious groups that will emerge in the future.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.3
• /
• pp.20-40
• /
• 2003

Since unloaded Q-value of a high-temperature superconductor(HTS) filter is very high, a bandpass filter(BPF) and a lowpass filter(LPF) with an increase of pole numbers can be fabricated without an increase of an insertion loss(IL) ; recently a 70-pole BPF is developed in USA. They have an abrupt skirt property and an excellent attenuation level for out-of band. Moreover, they can be miniaturized when lumped element resonators or the slow-wave characteristic are used. Technology of fabricating a HTS epitaxial film as well as a film of a 4 inch area also makes the planar type filter with a various structure and an enhanced power handling capability possible. Recently, the HTS filter subsystems composed of a planar-type HTS filters, a GaAs-based LNA and a mini-cryocooler are developed. The extended receiver front- end subsystems for mobile radio communications decrease the noise-figure level of the communication system and the frequency interference interacted adjacent bands, and increase the efficiency of frequency and the capacity of communication system. In this paper, theory for developing the HTS filter, its kinds, its design rules, its characteristics are reviewed. The feature of the research and market trends related to the HTS filter systems for the receiver front-end subsystem of mobile base station are surveyed.

• The Research Journal of the Costume Culture
• /
• v.4 no.2
• /
• pp.113-124
• /
• 1996

This research was designed to find out what is a distictive feature of the design elements of Korean women's costume and its influence by analizing the trend of Korean women's constume during the period of 1890 and 1995. The research was analized by a total of 854 random samples of clothing styles collected from materials in the museums and from articles of three leading newspapers and one of the best women's magazines in Korea. The changing trend of Korean women's costume was found out to be as follows: 1. In around 1910s, the trend of Korean women's costume has been changed into two-tier structure of both Korean and Western styles, and the typical and traditional Korean women's street wears such as 'Chang-ot' and 'Tsdechima' have been gradually diminished. 2. From 1920s, length of the Korean skirt, which was unnecessarily long and inconvenient, has been getting shorter for the convenience of walking. In addition, Korean women's underwear has become simplified, and sports wear could be seen for the first time in Korea. 3. During 1960s, the Western clothing styles have been increased rather than Korean styles as the street wear of the Korean women. 4. In 1970s, blue jeans, mini-skirts and casual wears have become a trend or fashion for women in Korea. 5. In 1980s, a fashion of unisex mode has arrived in this country, and from the year of 1987, wearing of panties among the Korean women has been increased rather than skirts wearing for the street wear. 6. During 1990s, various forma of complex styles came into being in such styles as so-called 'orange class style,' 'protruding navel T-shirts' and 'runner wear speedy.' From mid-1990s, Korean women have turned out to prefer the cute and light costumes by placing emphasis on the image of intellectual, professional and functional wears. The changing special feature of the Korean women's clothing designs could be distinctively observed during 1960s as the modernization policies in Korea have been processed during the period. The clothing trend before 1960 was to change and to solve problems of inconvenient and impractical wears, but the trend after 1960 was seen as a change to confirm a trend of the world fashion. From mid-1990s, however, preference of Korean women's self-conceited conception socially and an unquestionable changing pattern of Korean women's life.

• Journal of the Korean Society of Costume
• /
• v.1
• /
• pp.119-129
• /
• 1977

It is significant for developing the future for us to know our present age. In order to preserve our Korean costume as a fola clothes retaining our distinguished independent characterisitics and to help design the tomorrow of our Korean costume playing a role as a racial to develop the world clothing culture, a survey was conducted to investigate modern people's conscious-ness and wearing practumes of Korean costume by questionaire and interviewing methods. The results of the survey were analyzed as follows: (1) At present, Korean costumes were purchased as customtailored(64.0%) and as ready-made(17.8%) and most of them were not made at individual homes. The laundry and ironing of them were carried out at laundry shops(68.8%). Considering our present economic, social and cultural aspects, sowing, laundryand ironing will not be carried out at homes again in the future and ready made costumes seen to be produced in a large scale in the future. Garment makers and laundry shop operators should be trained how to make our Korean costumes retain our traditional beauty in the course of their production and laundry and the makers of ready-made costumes must make research how to efficiently produce ideal ready-made costumes by adopting the synchro system in their wrk odisivion. (2) The age group wearing Korean costumes most frequently was the aged people over 60 (their wearing rate; 45%-50%) and the group wearing them most frequently next io the aged people over 60, was housewives(their wearing rate; 15%-20%). Excludign aged people and housewives, other respondentsdid not wear Korean costumes very frequently. Men's wearing rate was lower their wearing rate was the younger their ages were and the less their monthly incomes were. Korean costumes were used for holiday and festival(60%), wedding and funeral ceremonies (52%), visiting and working(22%), casual wear(12.8%) and home wear(9.2%). The use of Korean costumes as casual and home wears, was lower than the use for holday, festival, visiting and working, Under our present circumstances in which our Korean people use both Western style clothes and Korean costumer, our Korean costume has lostits position as a basic and necessary requiement in Korean people's daily life and become a ceremonical and fancy costume. It is natural that the times and life change everything in our daily life. Our costume has to be made as good ceremonial and fancy clothes satisfying modern sensibility according to its new role. In order for us to get close with our clothes, a keen study must be carried out to cleat the color, material, style, function and harmony of the Korean costume matching the of the times. (3) The 47.8% of the respondents answered that they were proud of our Korean costume as our folk clothes, 47.6% replied that thought them just common and 1.1% responded that they were ashamed of it. Most of them were affirmative in feeling pride with our Korean costume. (4) Considering the functional aspect of Korean costumes, their strong points were symetric beauty, rhythmical beauty, unity feeling, harmonical beauty and detailed decorations. Their common shortcomings were lack of individuality and inadequateness for active life. The shortcomings of woman costumes were suppressing breast, making resperation difficult and in adequnteness in summer time. The main reason not to wear our Korean costumes, was due to the fact that they are incomvenient for active life. As a measure to eliminate such shortcomings, 1) the suspension system of skirt to remove the suppression of breast should be generally adopted. 2) they should be simplified in their structure to make them convenient for active life and adepuate in wearing them in hot weather in an extent to which the traditional beauty of the costume may not be lostand 3) a new technique must be explored for showing individuality by wearing method and new arrangment of colors and decorations. (5) The reasons desiring to wear Korean costumes were classifide as follows: A. Korean costumes are our traditional clothes(43.4%). B. Korean costumes are noble and beautiful(26.8%). C. They are accustomed to wear Korean costumes by habit(19.5%). D. Korean costumes are necessary for attending ceremoneis(9.5%). E. Miscellaneous reasons(0.8%). Classifying these reasons into age groups, the high age group over 40 wore them because they were easy to wear by habit and the low age group of 10-30 never thought that they were east to wear by habit. Considering that even those who were accustomed to wear Korean costumes showed a low wearing rate and that the young generation were accustomed to wear Western style clothes rather than Korean costumes, the wearing rate of Korean costumes will be reduced in the future if such trend continues. It is urgent for us to make our best efforts in order to enhance the interest of young generation in Korean costumes and not to make them lose the strong points of Korean costume in the future. (6) Conicering the plan of the respondents on what kind of clothes they were going to wear in the future, among the age group over 50, those who wanted to wear only Korean costumes were 24.8%(men) and 35.1%(women), those who wanted to wear 49.7%(men) and 47.4(women), those who wanted to wear chiefly Western style clothes were 20.7% (men) and 14.4%(women) and those who wanted to wear only Western style clothes, were 2.4% (men) and 2.1%(women). This shows that the general tendency to wear only or chiefly Korean costumes is more prevalent than that to wear only Western style. Among the age group under 50, the tendency to wear Western style clothes was conspicuous and most of the respondent answered that they would wear chiefly Western style clothes and Korean costumes occasionally. Only 5.4% of the respondent answered that they would wear only Western style clothes and this shows that meny respondents still wonted to wear Korean costumes. Those who wanted their descendants to wear what they desire, were 50.1%(men) and 68.8% (women) and those who wanted their descendants to wear Koran costumes occasionally, were 85.8%(men) and 86.3%(women). This shows that most of respondents wanted their descendants to wear Korean costumes. In order to realize, it is necessory for us to make ourdescendants recognize the preciousness of our traditional culture and modify our Korean costumes according to their taste so that they may like wearing them.