• Journal of electromagnetic engineering and science
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• v.19 no.2
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• pp.96-100
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• 2019

A compact wideband crossover coupler with fully lumped elements is presented. To achieve a wideband operation, a three-section branch-line structure is employed for the crossover coupler. The size is significantly minimized by replacing transmission lines with lumped elements. The measurement shows that the insertion loss, isolation, and return loss are 1.7 dB, 24 dB, and 14.5 dB, respectively, at 2 GHz. The fractional bandwidth of 20-dB isolation and 3-dB insertion loss is 27%. The size of the crossover coupler is 11 mm × 9 mm, which corresponds to 0.07λ × 0.06λ at 2 GHz. This is significantly smaller than a conventional three-section branch-line crossover coupler by 95%.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.403-411
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• 2020

This convergence study examines the case of the Andaz Hotel branches, which sees the critical elements of a characteristic boutique hotel as an experience and makes a successful case with rich experience content in the hotel. By examining sixteen experience content categories, eight from the Andaz India Delhi branch and Tokyo branch in Japan and analyzing them through Schmitt's five experience modules, we have found that both branches had strong experience content in most of the modules, in line with the brand philosophy of creating hotels that make the most of the local characteristics. The study also showed that the Toranomon Hills branch had stronger emotional experience contents than the Delhi branch, and the Delhi branch had a little stronger in the case of cognitive experience contents. Both branches were found to have rich experience content at various points encountered by the guests while using the hotel.

• Journal of Trauma and Injury
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• v.34 no.4
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• pp.288-293
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• 2021

In South Korea, most patients who visit trauma centers with abdominal injuries have blunt trauma, and penetrating injuries are relatively rare. In extremely rare cases, some patients are admitted with a long object penetrating their abdomen, and these injuries are referred to as abdominal impalement injuries. Most cases of impalement injuries lead to fatal bleeding, and patients often die at the scene of the accident. However, patients who survive until reaching the hospital can have a good prognosis with optimal treatment. A 68-year-old female patient was admitted to the trauma center with a 4-cm-thick tree branch impaling her abdomen. The patient was transported by a medical helicopter and had stable vital signs at admission. The branch sticking out of the abdomen was quite long; thus, we carefully cut the branch with an electric saw to perform computed tomography (CT). CT revealed no signs of major blood vessel injury, but intestinal perforation was observed. During laparotomy, the tree branch was removed after confirming that there were no vascular injuries, and enterostomy was performed because of extensive intestinal injury. After treating other injuries, the patient was discharged without any complications except colostomy. Abdominal impalement injuries are treated using various approaches depending on the injury mechanism and injured region. However, the most important consideration is that the impaled object should not be removed during transportation and resuscitation. Instead, it should only be removed after checking for injuries to blood vessels during laparotomy in an environment where injury control is possible.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.317-321
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• 2016

Detection of micrometastasis in sentinel lymph nodes (SLNs) is a very useful tool for appropriate assessment of the clinical stage of disease in breast cancer patients. Early identification of clinically relevant disease could lead to early treatment or staging approaches for breast cancer patient. Micrometastases in SLNs of women with invasive breast cancer are of great significance in this context. In this study we examined SLN biopsies considered to have small numbers of cancerous cells by real time RT-PCR. All of the samples underwent immunohistochemical staining for cytokeratin for confirmation of the presence or absence of micrometastases. BUB1b expression assay of selected patients with and without metastasis showed overexpression in the former, but not in normal breast and lymph node tissue. Our results may be taken into account in the discussion about the merits of routine use of molecular assessment in pathogenetic studies of SLNs.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.656-658
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• 2011

A green and efficient method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones through one-pot three-component reaction of ethyl acetoacetate, an aryl aldehyde, and urea or thiourea in acetonitrile using silica gel-supported polyphosphoric acid (PPA-$SiO_2$) as catalyst is described. Compared to the classical Biginelli reaction conditions, the present methodology offers several advantages such as high yields, relatively short reaction times, mild reaction condition and a recyclable catalyst with a very easy work up.

• Korean Journal of Materials Research
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• v.27 no.7
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• pp.353-358
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• 2017

Recycled cenosphere, which is a hollow shaped particle from fly ash, has become attractive as a building material due to its light weight and excellent heat insulation and soundproof properties. In this paper, we investigated the effect of cenosphere size on the physical and optical properties. High brightness of cenosphere as raw material is required for a wide range of ceramics applications, particularly in fields of building materials and industrial ceramic tiles. Cenospheres were sorted by particle size; the microstructure was analyzed according to the cenosphere size distribution. Cenospheres were generally composed of quartz, mullite, and amorphous phase. Colour measurement corresponding to chemical composition revealed that the contents of iron oxide and carbon in the cenospheres were the major factors determining the brightness of the cenospheres.

• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.1998-2004
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• 2019

The Multi-Physics (MP) instrument is one of 20 neutron spectrometers planned in the China Spallation Neutron Source (CSNS). This paper presents a shielding calculation for the MP instrument using Monte Carlo codes MCNPX and FLUKA. First, the neutrons that escape from the CSNS decoupled water moderator and are delivered to the beam line of the MP instrument are calculated to use as the source term of the shielding calculation. Then, to validate the calculation method based on multiple variance reduction techniques, a cross check between MCNPX and FLUKA codes is performed by comparing the calculation results of the dose rate distribution on a simplified beam line model. Finally, a complete geometry model of the MP instrument is set up, and the primary parameters for the shielding design are obtained according to the calculated dose rate map considering different worst-case scenarios.

• Journal of the Korean Geographical Society
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• v.29 no.1
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• pp.84-104
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• 1994

The migration of population into the city has been on the increase according as Korea has been industrialized repidly since the 1960's. And there is a steady decrease in rural population. Thus lack of the number of the students forced many elementary Schools to be abolished. The aim of this study is to grasp the abolition types and the regional characteristics with the subject region of Chungbuk province. From the viewpoint of the increasing abolition of the elementary schools, I think it is very important to understand how the elementary schools have been abolished so far and predict how the subject region will have been changed in geography. Data for this study are based on Annual Establishment-Abolition Situation of the Schools published by Chungbuk office of Education in 1992, and many Kinds of the statistical reports, and the interview with the related. The results are as follows: 1. By examining the change of the number of the elementary schools and students in Chnugbuk, the numder of the students had also decreased since 1969 and was less than the half in 1990. As the number of the schools began to decrease ten years later than the students began to, the abolition of the elementary schools has started in reality from 1980's. 2. The 72 elementary schools were aboilshed between 1980 and 1992: the principal school is 9.7%, the branch school is 90.3%. The most fifteen schools are abolished in Yongdong-county and Chechon-county, and the least one school is abolished in Chechon-city and Okchon-county, and there is no abolition in Chongju-city and Chungju-city: According to the type of the abolition process, the least seven principal schools are abolished, and the principal school is reorganized as a branch school and twenty eight branch schools are abolished, and the most thirty seven branch schools are abolished. 3. When special change of the abolition is classified into the first perio (1980-1986) and the second period (1987-1992), in the first period the principal and branch schools were abolished and they are 13.9% of total abolition. The abolition out of them by building a dam is 60%. The principal schools in the submerged area though they have many students, were abolished. In the second period sixty two branch schools are abolished and they are 86.1% of total abolition. The most fifteen schools are abolished in Yongdong-county, thirteen in Chechon-county, seven in Tanyang-county, six in Chongwon-county, five in Chungwon-county and Koesan-county. Unlike the first period, the schools were abolished in this period because the number of students was so small. In this period sixty branch schools were abolished. All the students in the abolished schools except six schools transfered to the principal schools. The 58 school authorities help the students attend school by bus or support the expenses for attending school after that. 4. The abolition types of city, county and myon are classified into five types by the number of the abolished schools. The most forty nine abolished schools in type II are 68.1 of the total abolition. The least three abolished ones in type I are 12.5%. Considering the relation between the abolition type ane the number of schools and students, the number of the schools, increased in type I, II, III, V except IV from 1980 and then have decreased by abolition since 1980, while the more students decreased than they did in 1970 and the more the abolished school increases, the less the students decreases. The average students per school decreased in every abolition type and the most students decreased in type IV. 5. Considering the relation between the abolition type and the regional characteristics, most abolished schools were located between 100m and 300m above the sea level and it is 71% of the total abolition. The region without the abolition is high in the ratio of the cultivate land, ratio of rice field, and the part-time farmer, but the region with many abolition is low in the ratio of cultivated land. As for the manufacturing there are the most city, county and myon in the abolition type in Youngdong-county and Chechon-county where the manufacturing ratio of employing is low but Chongju-city without the abolition is a region where the manufacturing ratio is high. Consequently the development of the manufacturing causes the population to emigation out and the decrease of the population leads the transport is difficult of access, the facilities sold after being abolished are not being used in many ways. 7. Take an example of Youndong-county where the most schools were abolished, I have examined the school district and the population characteristics of the abolition. Though there were more villages, households, populations in the region that is higher than low above the sea level, the schools were abolished. Therefore we know that above the sea level had a great effect on the abolition. As a result of the regional analysis of the abolition, many schools were abolished by the artificial buildings such as a dam in the early 1980's but the schools in the late 1980's were abolished ten years later after the students decreased. More schools were abolished in the region where the manufacturing industry didn't develop. And the higher the school position was above the sea level, the sooner the school was abolished. It is also proved that both the beautiful natural scenery and accessibility are the important factor in using the abolished facilities practically.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.354-355
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• 2005

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.97.2-97.2
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• 2006