• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.228-231
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• 2013

This paper proposes a new method that reduces RCS(rader cross section) of the aluminum plate using a oscillation system composed of a VGA(variable gain amplifier) and a phase shifter. Once the oscillation system receives the external-RF signal through a probe on aluminum plate, it makes an amplified signal with a specific phase to cancel the signal reflected from the aluminum plate. The signal transmitted from the oscillation system has the same amplitude and out of phase with the reflected signal. And it can be controlled by the VGA and the phase shifter in the oscillation system. In order to validate the performance of the proposed oscillation system, FEM simulator was used and we measured how much an amplitude of the signal reflected from the aluminum plate rotated in phi direction is reduced in an anechoic chamber.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.8
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• pp.872-878
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• 2014

This paper proposes a measurement method of the complex relative permittivity of semi-solid materials using a new cavity structure. Semi-solid materials are positioned in the proposed cavity where an aperture exists on each corner of the upper part and a ground plane is separated. In order to show the validation of the proposed method, we measured the complex relative permittivity of distilled water and 0.9 % saline by sensing a shift of resonant frequency and using Critical-Points Method, and compared the results with those derived from the Cole-Cole equation.

• Journal of the Korean Society of Costume
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• v.31
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• pp.131-144
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• 1997

This thesis is mainly on the study of Gongbok and Sangbok in the system of official outfit of the Koryo dyn-asty which has not yet fully studied in the history of Koren dress and its ornaments. Even in this difficult circumstances the sys-tem of dress and its ornaments can be under-stood with the help of remaining Buddhi-stliterature. Thus the system of official outfit in the Koryo dynasty has been studied here with some documentary records such as Koryo-dokyung Koryosa-yeobokji (The His-tory of Dress And Its Ornaments in The Koryo Dynasty) and so on. As the Koryo dynasty de-veloped her international relationships continu-ously with her neighbouring nation which were geographically closely connected so the systems of official outfit in the Chinese dyn-asty of Sung had to be studied and compared with, In the Koryo dynasty the same four colour system of purple red, deep red and green had survived until the year of 1123 from the year of 960 not using the blue colour from the four colour system of purple Chinese red green and blue of the Sung dynasty. The four colour system of purple deep red green and black under the regin of the King Euijong was exactly the same as that of official outfit of the Sung dynasty in he year of 1078 the first year of Wonpung's regin and wearing Eodae is a sure sign of influence of the system of Sung dynasty. Even though Koryo was invaded by Yuan druing the period of the regin of the King Chungyul the four colour system was not changed of purple deep red. green and black along with the same Dae-sudanryung(long sleeve and round collar). In 1387 the thirteenth year of the King Woo of the Koryo dynasty Pumdae was used ofor different official ranks and the sys-tem of wearing Samo and Dayung was established for the official outfit of every government officers.

• 한국해양학회지
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• v.5 no.2
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• pp.41-51
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• 1970

Periodic characters of water temperature in the regions of the Mishima and the Okinoshima were derived through the analysis of the five days interval data during 1914 to 1970 mainly. In terms of ten days mean temperatures, annual variation function of the Mishima region, Korea Strait, is F($\theta_d$)=17.45-5.34 cos $\theta_d$-3.77 sin $\theta_d$+0.62 sin $2\theta_d$ -0.52 sin $3\theta_d$, where $\theta_d$=$\frac{\pi}{18}$(d-2), d is the order of ten days period 1 to 36. And in the region of Okinoshima, Tsushima Strait, we find F($\theta_d$)=18.88-5.39 cos $\theta_d$-3.60 sin $\theta_d$+0.52 sin $2\theta_d$. The annual mean temperature is 17.4$^{\circ}C$ in the Mishima region, 18.9$^{\circ}C$ in the Okinoshima region, and the amplitudes of annual variation functions are 7$^{\circ}C$ in both regions with minimum temperature in the middle ten days of February, maximum in the middle ten days of August. The long term variations of surface water temperature with 12 5 years period were observed in the annual mean temperature, monthly mean temperatures and the fixed day temperatures of every year. In addition to these, relatively short term variations were also found significant periods of 3 years, 4 years and 2 years, respectively.

• Journal of the Korean Society of Costume
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• v.65 no.4
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• pp.1-18
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• 2015

The subject of study is about the illustrations of the round collar Po(袍類) in the Akhak-gwebeom(樂學軌範) which was published in 1493. These illustrations are painted records of what musicians and dancers in the palace were wearing during performances. While each illustration of the Po is similar in that they all have round collars, each has a different name Sam(衫), Ui(衣), Dallyeong(團領) and formative characteristics, and these features were analyze in the study. Sam refers to the Gongbok(公服) as it has long and big sized sleeves, Ui is the word used to represent the basic unit of outerwear, and Dallyeong is believed to refer to the Sibok(時服) and Sangbok(常服). In the formative aspects, Sam's auxiliary sleeve is one of the ways wearing the sleeve of innerwear shown outward and it's assumed to have been produced for visually matching the formal look as well as the convenience free to use of hands. The Mu of Dan-ui(丹衣) is less than the number of the excavated artifacts, it produced in a relatively simplified form. Also, illustration of Dallyeong corresponds to the artifacts and configuration of the 15th to 16th centuries, the costume culture of that time seems to be reflected specifically. While Hyungbae(胸背) used in the form of rectangles and circles such as petals. it tried to represent the country at the official event by borrowing the upper class in the costume that musicians and dancers wear, also showed the rank and social status symbolically by having the differences in the shape and pattern. While the costume culture at the time is reflected, it can be found that the objective of raising the country's dignity is implied by transforming the detailed structure for the practicality, borrowing the costume elements of the high social status and transformed them.

• Journal of the Korean Society of Costume
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• v.61 no.4
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• pp.52-62
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• 2011

This study is about the history of costumes depicted on the book Goryosa(高麗史) Ye-Ji(禮志). Researches about the costumes of Goryo dynasty are very rare and are mostly based on Goryodogyung(高麗圖經) and Goryosa Yebok-Ji(與服志). However, records about suitable costumes for a special scene of a rite can also be found in Ye-Ji besides Yebok-Ji. Therefore, this study analyzes Ye-Ji and categorizes the results into character and situation. Characters that can be found are king, officials, crown prince, aristocrat, commoner and envoy. Situations that can be found, according to the original text, are Gilrye(吉禮), Hyoongrye(凶禮), Goonrye(軍禮) and Garye(嘉禮). The results of the study are as follows; $\blacktriangleright$ The king had to change clothes in order to suit the situation according to the precise sequence of rituals. Therefore the king had to wear different clothes in the same rite, optionally, depending on the situation. This also applies to the case of officials. $\blacktriangleright$ The crown prince and aristocrats generally wore the same clothes as officials. $\blacktriangleright$ In the important ritual of Garye(嘉禮), many cases can be found where officials wore Jobok(朝服) and hands-on worker wore Gongbok(公服). $\blacktriangleright$ It is remarkable that on the New Year's day, the winter solstice and Sungsoojul(聖壽節; the emperor's birthday) the envoy of Ming Sangbok(常服); whereas the king and the officials of Goryo wore the Myunbok(冕服) or Jobok(朝服).

• 한국해양학회지
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• v.15 no.2
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• pp.123-128
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• 1980

Variabilities of tidal range at Inchon were described based on observed values. Relationships between tidal ranges and harmonic costants of tide were also examined. Fortnightly variation is predominant and its range is 571.3cm. Mean of maximum spring range(ΔH/sun max/) is 887.2cm and that of minimum neap range(ΔH/sun min/) is 315.9cm. Mean tidal range(ΔH) is 634.3cm. Diurnal inequality is shown about 141cm on an average and monthly inequality is also shown about 100cm. Yearly inquality appears with a range of about 35cm, maxima in March and September, and minima in June and December. There may exist 18 1 years periodicity with a range of about 45cm. There are some relationships between ridal ranges and amplitudes of M$\_$2/ and S$\_$2/, such as ΔH=2.172 H$\_$m/, ΔH$\_$max/=3.043 H$\_$m/, ΔH$\_$min/=1.071 H$\_$m/, ΔH$\_$max/=2.198 (H$\_$m/ + H$\_$s/), and ΔH$\_$min/=1.740 (H$\_$m/ - H$\_$s/).

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.200-221
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• 2019

The National Hangeul Museum houses a document list of the wedding gifts that Queen Sunwon granted her royal son-in-law, Nam Nyeong-wie, in August 1837. A total of 55 items were recorded in Hangeul Gungseo style on yellow paper. This list included four types of government officials' uniforms, casual wear, accessories, etc. The results of studying the 19th-century male officials' uniforms through this historic record were as follows. The clothing record in the List of Wedding Gifts was more accurate than that in the Dukongongju Garyedeungrok. The four types of government official uniforms for Nam Nyeong-wie included jeobok, sangbok, sibok, and gongbok. For the joebok, there was geumkwan, daehong-hangrah joebok, baeksam, ahole, seodae, gakpae, peseul, paeok, husu, and mokhwa. The record of the List confirms that baeksam was used as jungdan for joebok. For the gongbok, there was daehong-hangrah gongbok, blue seolhancho duhgre, blue saenggyeonggwangju changui, and green waehangrah kurimae. The record of the List shows that the lining of the gongbok was duhgre, and confirms, for the first time, that changui and kurimae were worn inside the gongbok. For the sangbok, there was samo, ssanghakhyungbae embroidered with golden thread, dark green cloud patterned gapsa gwandae, blue cloud patterned gapsa duhgre, blue ssangmuncho changui, and Chinese purple hwamunsa kurimae. For the sibok, there was pink gwangsa gwandae, and blue gwangcho duhgre. For the lining, blue duhgre was used. Lastly, the fabrics used for those costumes were all suitable for the climate in August.

• Particle and aerosol research
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• v.15 no.2
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• pp.79-90
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• 2019

It is important to control fine particles in children care centers, elementary schools, elderly care facilities and so on where vulnerable children and the aged stay during most of their time. This study has investigated $PM_{2.5}$ and $PM_{10}$ concentrations in two classrooms equipped with an air cleaner and two air cleaners, respectively and they were compared to those in a classroom without an air cleaner as well as those outdoors. Eight air cleaners which have various clean air delivery rates (CADRs) between 9.9 and $21.3m^3/min$ were tested in classrooms in two elementary schools in Seoul. Average $PM_{2.5}$ and $PM_{10}$ were $7.3{\pm}0.7$ and $45.5{\pm}4.1{\mu}g/m^3$ in classrooms equipped with an air cleaner and $4.2{\pm}0.6$ and $24.6{\pm}2.5{\mu}g/m^3$ in classrooms with two air cleaners, whereas they were $22.1{\pm}2.6$ and $109.1{\pm}9.6{\mu}g/m^3$ in classrooms without an air cleaner and $36.9{\pm}5.1$ and $74.1{\pm}10.6{\mu}g/m^3$ outdoors, respectively. $PM_{2.5}$ in classrooms could be reduced effectively by using an air cleaner or two air cleaners, because $PM_{2.5}$ was mainly infiltrated from outdoors, however $PM_{10}$ could not because $PM_{10}$ was mainly caused indoors by students' activities. Air cleaners were more effective for removal of $PM_{2.5}$ and $PM_{10}$ in classrooms with a high airtightness than those in classrooms with a relatively low one. Average $CO_2$ in classrooms was about 1500 to 2000 ppm for class hours dependent on the student number per a classroom, which was about 1.5 to 2 times higher than the standard, regardless of the use of air cleaner.