• Journal of the Korean Magnetics Society
• /
• v.18 no.3
• /
• pp.120-125
• /
• 2008

In this study, NiCoZn ferrites with the variation of sintering temperature and chemical composition were prepared by the coprecipitation. Microstructures Crystal structure of NiCoZn ferrites were analyzed by XRD and their electric magnetic characteristics were analyzed by LCR meter and their morphology observed by SEM. We identified that these powders have a typical NiCoZn spinel structure and nanoparticles average size of 40 nm. The impurity, the initial permeability and the Q factor value are the lowest of sintered NiCoZn ferrite at $1250^{\circ}C$. Also, we measured S-parameter for $(Ni_{0.4}Co_{0.1}Zn_{0.5})Fe_2O_4$ which showed a maximum reflection loss of -3.1 dB at 6 GHz for the 2 mm thick sample. From this result, we found that the NiCoZn ferrite can be used in ferrite microwave-absorbing application at a higher frequency region (> 6 GHz).

• Korean Journal of Plant Taxonomy
• /
• v.38 no.2
• /
• pp.79-91
• /
• 2008

Asplenium yoshinagae (Aspleniaceae), previously known only from Japan, southwest China to Himalaya, was found in Gageo-do, Heuksan-myeon, Sinan-gun, Jeollanam-do. This species is similar to A. trichomonas, A. tripteropus, A. boreale, A. normale and A. oligophlebium by having gemmae and auricle of pinna, and distinguished from the latters by distinct stipe length, stalk of pinna, acute apex of pinna, length of indusium and shape of sorus. The Local name, Ga-geo-kko-ri-go-sa-ri, was newly given considering the locality. To reveal the interspecific relationships within the genus Asplenium in Korea, cladistic analysis was performed for 22 taxa of Asplenium as ingroup and 2 taxa of Diplazium as outgroup from Korea based on 20 morphological characters. As the results, the genus Asplenium seperated strongly from outgroup, and divided into 4 clades. Asplenium yoshinagae belong to the third clade. A. hondoense N. Murtakami & S. I. Hatanaka, which contained in the second clade, had treated as Hymenasplenium, but this results supported that this taxon may be contained in Asplenium, and also, Asplenium ruprechtii, not in Comptosorus. The morphological characters and illustrations of the species are provided together with photographs of habitat.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.10 no.2
• /
• pp.47-57
• /
• 2007

Real-time oceanographic information system was developed using platforms of aquaculture farms to examine causes of mass mortality of hatchery fishes, and to reduce the damage of mass mortality which has been occurred frequently off coast by abnormal change of ocean conditions. The system had the advantages of direct data distribution to fishermen at the farm and instant maintenance of equipments due to easy access to the farms and residents at the farms in comparison with offshore mooring buoy system. To avoid discontinued measurement of the system, repairs caused by malfunction of equipments, bimonthly preventive maintenances and daily monitoring of measured data were systematized. Confidence intervals calculated by a statistical method using accumulated data were applied to data management. Such activities could minimize discontinuance of measurement and keep information more trustful. In addition, the system has various ways of data distribution. Through homepage and e-mail in the internet, information was provided to public. Display units which were connected to equipments at the farm gave the measured data directly to fishermen, which guided them to run their farm scientifically. Finally large display unit was installed at a fish market and showed the measured data at the nearest station with tide and weather information. Proper region for aquaculture and wintering region were studied using temperature data obtained by the system in 2006. The system will contribute to reduce economic damage of coastal fishery and to understand coastal marine environment.

• Journal of Radiation Protection and Research
• /
• v.32 no.2
• /
• pp.59-64
• /
• 2007

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet B (UVB) irradiation and observed the effect of bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BLE) on the formation, and decrease of UVB-induced epidermal melanocytes. C57BL/6 mice were irradiated by $UVB\;80mJ/cm^2(0.5mW/sec)$ daily for 7 days, and BLE was intraperitoneally or topically applied pre-or post-irradiation. For the estimation of change of epidermal melanocytes, light microscopic observation with dihydroxyphenylalanine (DOPA) stain was performed. Split epidermal sheets prepared from the ear of untreated mice exhibited 11-16 $melanocytes/mm^2$, and one week after UV irradiation, the applied areas show an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal or topical treatment with BLE before each irradiation interrupted UVB-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to radiation control skin. The number and size of DOPA-positive epidermal melanocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with BLE at 3rd and 6th weeks after irradiation. The results of present study indicate that BLE is likely to be useful as inhibitor of UVB-induced pigmentation and depigmenting agent.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.32 no.4
• /
• pp.301-306
• /
• 2016

It is very hard for edentulous patients to satisfy retention and stability with their complete denture. Especially, for patients with systemic diseases such as Parkinson's disease causing involuntary and limited movements, fabricating complete dentures may be challenging to both dentists and patients due to functional limitations. To overcome this problem, overdentures can be used through conserving retained roots. In this case, a 45-year-old male patient had to extract numerous teeth due to dental caries, and at the time of visit he was taking drugs for diabetes and Parkinson's disease for a period of long time. A complete denture was applied to maxilla, and for mandible, an overdenture on two preserved retained roots was applied where its retention and stability were obtained by magnetic attachments. This case reports that overdenture with retained roots improved overall functional limitations.

• Journal of the Korean Society for Library and Information Science
• /
• v.50 no.1
• /
• pp.395-416
• /
• 2016

This study analyzes periodic phenomena on publication and characteristics of Buddhist scriptures engraved on woodblock in temples located in Hwanghae Province during the Joseon Dynasty period in bibliographic approach. There are total 85 Buddhist scriptures published in Hwanghae Province, 5 scriptures among them including Yonggamsugyeong appear to be engraved on woodblock only in temples in Hwanghae Province. They, published in 64 printings during the early days of the Joseon Dynasty, occupy 75% of total Buddhist scriptures, and are analyzed to be intensively published with the support of royal family members such as Queen Munjeong in the reign of King Myeongjong. However, as the publication displayed a sharply declining tendency in the late Joseon period after the Japanese invasion, it is understood to be identical with historical fact that the people's livelihood in Hwanghae Province closed to ruin through invasions from Japan and Manchuria. In addition, the analysis on characteristics of these Buddhist scriptures by subject indicates that over 80% of them are generally sacred books and dogmas. In fact, woodblock engraving works in temples emphasize on the duty of an engraver, and many engravers are investigated that they engraved only 2 to 3 Buddhist scriptures in temples located in Hwanghae Province. Doseong and Suyeon can be regarded as remarkable itinerant monks as they were appeared to engrave Buddhist scriptures in not only Hwanghae Province and also other regions by moving from one place to another. This study is expected to be meaningful as a paper that can be used on future studies to compare Buddhist scriptures engraved on woodblock in other regions in North Korea.

• Journal of Biomedical Engineering Research
• /
• v.19 no.4
• /
• pp.379-384
• /
• 1998

To measure precisely the blood velocity in the skin microcirculation, we have used time domain correlation (called Cross-Correlation) based on the processing of the backscattered RF signal obtained with a wideband echographic imaging transducer, although it is difficulties of adaptation of the pulsed wave system, because of the data processing in real time and the hardware problem. This dedicated technology based on a 20MHz echographic imaging system has been developed. We present how the experimental data, i.e. the backscattered RF signal, have to be analyzed. After RF lines realignment, stationary echo canceling procedure and correlation level control, a velocity profile has been obtained. In-vitro result show that velocity measurements as low as 0.1mm/sec attainable with a 80${\mu}m$ in axial resolution. We have also validated with in-vivo experimentation on the external ear of a rabbit using B-mode sector scanning image and M-mode image of a custom made 20MHz skin image system. The flow of the "auriculares caudales" vein, a microvessel of 600 m diameter, has been detected and studied. This technique will allow a more precise exploration of circulatory troubles in cutaneous pathologies.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.14 no.2
• /
• pp.81-90
• /
• 1986

The full grasp of recreation demand and factors affecting on recreation demand can be very important information for park planning and management. The object-tives of this study are to investigate factors affecting the fluctuation of urban park visitors and to analyze the relationship between these factors and the daily parti-cipations. The results were as follows; 1) The peak of monthly participations comes on May, April, August and October in order. And these months are specified as school picnic period and vacation of school children. 2) In correlation analysis, the variables such as ‘Day of a week(D)’, ‘Monthly mean temp.(T)’and ‘Monthly character(M)’have high correlations with ‘No. of visitors’in order. And it is better to categorize months by its charater(picnic period in school, vacation etc) than by seasons. 3) Candidate regression model were established, as for 1984 log U= 1.51 + 0.64D1 + 0.02T + 0.36W1 - 0.23M4 + 0.003SS + 0.24Ml($R^2$=0.5326) where, U=no. of daily visitors D1 = sunday.ho1iday(1), weekday(0) T=monthly mean temperature($^{\circ}C$) W1= weather (sunny.cloudy(1) , rainy (>5mm)(0)> M4=non vacations and non school picnic period(1) , if not (0) SS=monthly sunshining hours M1=summer vacation(1), if not(0) 4) The most important variable was ‘Day of a week’(sunday.holiday or not). And temperature, weather and monthly charcter(especially picnic period of school and vacation) were in turn, hence ‘Children's grand park’shows the use pattern of park.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.9
• /
• pp.722-727
• /
• 2013

Medical treatment for animals is very difficult as the opinions of pets' masters take priority over treatment regardless of the seriousness of pets' disease or the needs of medical treatment. In case that a pet has heart disease, especially, it is difficult to get the direct answer from the pet's master on the decision or confirmation of treatment. For those reasons, it is almost impossible to predict and treat the pet before an emergency like the heart failure or an unexpected death happens. Using stethoscope can be the first diagnosis method to check the heart or any kinds of disease inside the body. High-tech equipments like CT, X-ray or Ultrasound can be used, but they can only be used as a second choice of diagnosis method since it requires professional skills and its high price. That's why stethoscope is still the best diagnostic tool when one makes the first diagnosis. In this study, we give a detailed account of digital diagnosis system in which veterinarians can analyze the sound from stethoscope without bringing it to their ears and make a diagnosis wherever they are. And we suggest a new concept of diagnosis system surrounding, which shows the relativeness of disease through Level Crossing Rate(LCR) and energy level from the stethoscope sound made in this system.

• Journal of the Korean association of regional geographers
• /
• v.3 no.1
• /
• pp.99-113
• /
• 1997

The purpose of this study is to find out about the cause and adaptation process of urban households going to rural areas for agricultural management(Kwihyang nongga) through the microscopic analysis of a case study. Research results are summarized in the followings. The cause of Kwihyang nongga before the 1980s was generally due to the social causes like the support of dependent family or rural-to-urban migrants' maladjustment in urban society. After the 1980s, however, it was related to the economic reasons such as the increase of households' income by commercial agriculture more than the social ones. Most of Kwihyang nongga was traditionally the households which came back to their native places, rural areas. Recently the urban households which did not originally come from rural areas are going to rural space because of the cultivation of high profit oriented agricultural products. Recent Kwihyang nongga increased the size of commercial agriculture through leased farmland, not by a purchase of agricultural land. Even though the number of Kwihyang nongga is now a few, it is expected that the influence of Kwihyang nongga on rural society will be various and high because it consists of young generation. The increase of Kwihyang nongga may be one of the ways to mitigate the decreasing rate of utilization of agricultural lands due to the labor shortage of rural areas after industrialization. To solve rural problems related to underpopulation, it is necessary to establish the active plicies of helping Kwihyang nongga. The actions for Kwihyang nongga ought to emphasize the improvement of educational conditions and living facilities as well as financial aids and the improvement of farming conditions.