• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.1-13
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• 2012

Short implants are used in parts which have anatomical structures like maxillary sinus, inferior alveolar nerve and limited alveolar height due to severe alveolar bone resorption. In these case, there are no need of additional bone augmentation so there are advantages like reduced entire treatment time, reduced patient's discomfort and protection of important anatomical structures. The aim of this study is, in implants whose length is less than 10mm, to analyze the impact of implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting on survival rates and marginal bone resorption. The samples used in this study were 227 implants, less than 10mm, placed in 137 patients in Wonkwang university dental hospital implant center. From dental charts the information about implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting were obtained. Emago advanced v5.6(Oral diagnostic systems, Amsterdam, The Netherlands)program was used to measure the amount of marginal bone resorption. Out of total 227 implants, resulting in 96.5 % of survival rate. There was a tendency toward higher failure rates for the maxilla and bone graft site. No significant difference in marginal bone resorption was found associated with length of implants(p>0.05) and neither with the diameter of implants. Among the risk factors examined, more failure rates of short implants can be attributed to poor bone quality in the maxilla and presence of bone graft. At implants under 10mm, length, diameter, location of implant placement, bone graft and splinting of prosthesis didn't affect marginal bone loss.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.373-401
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• 2015

The UAV(Unmanned Aerial Vehicle, Drone) technology has been undergoing rapid progress, accompanied with a growth in the market. However, domestic industry standards and technology lag behind such progress happening on the international scene, and in particular in developed countries. Related regulations are also deemed lacking to address the issues that arise with such developments. Meanwhile, as the rise of UAV technology is a fairly recent phenomenon, the gap between Korea and developed countries is not too big. As this technology has high relevance to information and communication technologies, it also offers ample leeway for Korea to catch up in the field of UAV. As such, this paper seeks to provide a survey of the overall technology, market and regulations concerning UAV to identify possible measures on how to address any issues that may arise through proper policies. Due to the progress made in the field of UAV technology and increased penetration rate, striking a right balance between putting in place a proper regulatory system and establishing policies that foster growth in the field has risen as a very important issue. While the importance of establishing a legal system that helps prevent possible risks is indeed important, it must also be acknowledged that excessive regulation can also hinder technological progress. This, in turn would stagnate the market and dampen the entrepreneurial spirit in the society. In the case of new, practical technologies such as UAV, a prompt establishment of regulatory systems and policy measures in terms of policies is a requisite. In brief, in order to promote progress in the UAV industry and at the same time, for public safety and the protection of privacy, there should be an appropriate level on the easing and tightening of the regulation.

• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.186-191
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• 2007

To provide some ecological information on protection and management of the mixed heronries, their distribution, breeding species and individual numbers, and site characteristics, which may be important to heron ecology, were investigated in Jeollanam-do during the 2005 breeding season. As a result of this census, 17 mixed heronries, containing a total of six ardeid species were found. Among those species, Great Egret (Egretta alba) and Grey Heron (Ardea cinerea) were found to breed in most sites (both 92%) and were most numerous (36.3%, 31.0% respectively). Many of the heronries (53.3%) were located within the bamboo forest. Other site characteristics were as follows: the mean area dimension of heronry was $2,346m^2$ with the range of $500{\sim}7,000m^2$ the mean distance between the two nearest heronries was 18.1km with the range of $5.6{\sim}40.4km$ the mean distance to the nearest village was 297m with the range of $10{\sim}2,000m$ the mean gradient of the topography was $18^{\circ}$ with the range of $2^{\circ}{\sim}40^{\circ}$, and 40.0% of the heronries were located in the eastern slopes.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.295-307
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• 2015

Surveys of weed species in paddy fields were conducted to identify weed occurrence on July 2013. Total 237 sites of paddy fields in 9 City/Gun, Jeonnam Provinces in Korea were investigated. From the survey, 45 weed species in 18 families were identified and classified to 33 annuals and 15 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (9 species) and 8 and 4 weed species belonged to Cyperaceae and Scrophulariaceae, respectively. These 21 weed species in the most four families accounted for 46% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (18.5%), followed by Monochoria vaginalis (12.3%), Lemna perpusilla (8.2), Eleocharis kuroguwai (5.2%) and Scirpus juncoides (5.2%). The most dominant weed species in machine transplanting paddy fields were Echinochloa spp. (14%), followed by Monochoria vaginalis (12%) and in water seeded rice paddy fields were Echinochloa spp. (25%), followed by Monochoria vaginalis (11%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields.

• Fire Science and Engineering
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• v.29 no.2
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• pp.73-78
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• 2015

Fire in the risk management subject belongs to high risk disaster which accompanies personnel and materiel loss. So, management of disaster and safety is required to include fire prevention activities, fire risk prediction and investment of safety management expense. Combustion toxicity is required by gas toxicity test (KS F 2271), to minimize human damage. In this study, gas toxicity test were experimented with regard to urethane sample (Depth 5~25 mm) to obtain basic data. Fire effluent exposing to experimental animal were analyzed by FT-IR (Fourier transform infrared spectroscopy). Combustion toxicity index Lethal Fractional Effective Dose ($L_{FED}$) of ISO 13344 was calculated. According to the result of calculating Lethal Concentration 50% ($LC_{50}$) based on $L_{FED}$, $LC_{50}$ of urethane sample containing certain level of fire load is confirmed as $118{\sim}129g/m^3$. Through this study, applicability of this method was confirmed for fire risk assessment. This method can provide information to predict human damage by toxicity combustion gas for securing safety.

• Journal of Korean Public Health Nursing
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• v.13 no.1
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• pp.41-62
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• 1999

Recently the request of the patients to participate in the medical courses has been expanding due to elevated sense of right on the people's health. merchandised medical treatment by mass supply, human right declaration of the patients, generalized medical informations by the mass media and the change of human relation between the medical personnels and the patients. Under these phenomena the accident by the nurses have been increasing by the area of the nurses having been expanded and their independent roles having been increased. Such nursing accidents are the important subject which the professional occupation of the nurses has been facing but legal protective capability of the nurses has been very weak. Therefore this study has examined the degree of the experience of the nursing accident that happens in the clinical nursing scenes in the general hospital to provide the basic materials for the protection and the counter measures of the nursing accidents. The following is the conclusion based by the above examination. 1) The general characters of the subjects of this study is that they are mostly single in their twenties and graduate from nursing college. Their total clinical career is above 5 years$(44.8\%)$ and their current clinical parts' career is between 1-3 years$(40.1\%)$. So these facts suggest that most hospitals has taken the working rotation policy on nurses. 2) The level of nurses' knowledge on the nursing law is accurate partially but isn't it patially. So it is suggested that nurses need the accurate information and education about the nursing law. But the nurses' attitude is very approved of the establishment of a unilateral nursing law. 3) The relation between the demographic characters of the subjects and their attitudes on the nursing law shows that there is no significant differences except the relation between the attitude 6(the sufficient level of education on nursing law in formal education course) and age. total clinical career. 4) The perception of the nurses shows that the cause of the nursing accident has been due to the heavy work$(78.2\%)$. short of professional knowledge and skill$(60.2\%)$, discordance with Doctors. patients and patients' families. They report the accident to the head nurse first$(81.8\%)$ and within 30 minute$(75.1\%)$. The hour of nursing accident frequently happened is regardless of service hour with $49.4\%$ in response rate. the highest rate. and the nursing accident happens in the night more than the daytime. Even though most nurses think that they are themselves responsible for nursing accident. it is found that the chief cause of the nursing accident is due to the nurses' heavy work$(78.2\%)$. So the causes of nursing accidents is analysed. it may be suggested that the endeavor of hospital and nursing organizations to decrease nursing accidents is very important. 5) The coping patterns of patients with nursing accidents are mostly active attitude such as a violent words$(69\%)$. sue or accusation$(36.4\%)$, monetary compensation $(35.6\%)$ except a understanding cases$(38.7\%)$. But the coping patterns of hospitals with nursing accidents are mostly to investigate the accurate cause.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.459-464
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• 2016

An outbreak of the migratory locust, Locusta migratoria, in the environment-friendly reclaimed plantations of forage crops in Sanyimyeon, Haenam-gun, Jellanam-do, Korea in August 2014 caused severe damages to various crops. Owing to its first occurrence in the Korean history, the causes underlying the outbreak and phase-transition of the migratory locust were not known. It is critical to establish the genetic relationship of the migratory locust in Sanyimyeon, Haenam-gun with the other previously reported strains in the world in order to understand the mechanisms responsible for its outbreak. The gene sequences of the 16S ribosomal RNA (rRNA) and displacement-loop (D-loop) of the mitochondria of various regional species of the migratory locust were used to perform the phylogenetic analysis. Our results suggested that the migratory locusts in Sanyimyeon, Haenam-gun are closely related with the Eurasian strains of the northern lineage. In future, these two mitochondrial genes can be used for elucidating the genetic population structures in migratory locusts in various regions. In addition, the sequence information of these genes can be used to enhance our understanding of the genetic basis of the outbreak of migratory locusts.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.83-92
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• 2005

This paper presents a watermarking approach that the 1-level Discrete Wavelet Transform(DWT) coefficients of a $64{\ast}64$ binary logo image as watermarks are inserted in LL band and other specific frequency bands of the host image using Multi-Resolution Analysis(MRA) Wavelet transform for copyright protection of image data. The DWT coefficients of the binary logo image are inserted in blocks of LL band and specific bands of the host image that the 3-level DWT has been performed in the same orientation. We investigate Significant Coefficients(SCs) in each block of the frequency areas in order to prevent the quality deterioration of the host image and the watermark is inserted by SCs. When the host image is distorted by difference of the distortion degree in each frequency, we set the thresholds of SCs on each frequency and completely insert the watermark in each frequency of the host image. In order to be invisibility of the watermark, the Human Visual System(HVS) is applied to the watermark. We prove the proper embedding method by experiment. Thereby, we rapidly detect the watermark using this watermarking method and because the small size watermarks are inserted by HVS and SCs, the results confirm the superiority of the proposed method on invisibility and robustness.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.93-102
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• 2010

Recently, FRP usage for strengthening RC structures in civil engineering has been increasing. Especially, the use of FRP to strengthen structures against blast loading is growing rapidly. To estimate FRP retrofitting effect under blast loading, blast tests with nine $1,000{\times}1,000{\times}150\;mm$ RC panel specimens, which were retrofitted with carbon fiber reinforced polymer (CFRP), Polyurea, CFRP with Poly-urea and basalt fiber reinforced polymer (BFRP) have been carried out. The applied blast load was generated by the detonation of 15.88 kg ANFO explosive charge at 1.5 m standoff distance. The data acquisitions not only included blast waves of incident pressure, reflected pressure, and impulse, but also included central deflection and strains at steel, concrete, and FRP surfaces. The failure mode of each specimen was observed and compared with a control specimen. From the test results, the blast resistance of each retrofit material was determined. The test results of each retrofit material will provide the basic information for preliminary selection of retrofit material to achieve the target retrofit performance and protection level.

• Journal of the Korean earth science society
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• v.38 no.2
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• pp.161-171
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• 2017

Observed ground motions are composed of three factors such as, seismic source, attenuation, and site amplification effect. Among them, the site amplification characteristics should be considered significantly when estimating seismic source and attenuation characteristics with more confidence. The site effect is also necessary when estimating not only seismic hazard in seismic design engineering but also rock mechanical properties. This study uses the method of H/V spectral ratio of observed ground motion between target site and reference site called a reference site method. In addition to using the vertical Fourier spectrum of the reference site, we try out the horizontal Fourier spectrum as a new method in this study. We analyze H/V spectral ratio of six ground motions respectively, observed at four sites close to Yedang Reservoir. We then compare site amplification effects at each site using 3 kinds of seismic energies including S waves, Coda waves energy, and background noise. The results suggest that each site showed similar site amplification patterns in S waves and Coda waves energy. However, the site amplification of background noise shows much different characteristics from those of S waves and Coda wave energy, which suggests that the background noises at each site have their own developing mechanism. Each station shows its own characteristics of specific resonance frequency and site amplification properties in low, high and specific resonance frequency ranges. Comparison of the method used in this study to the others that used different methods can provide us with more information about the dynamic amplification of a site characteristics and site classification.