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

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.576-587
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• 2012

As being actual physiognomical vegetation on Daegwang sand dune in Imjado, the widest area is occupied by Pinus thunbergii community planted as windbreak forest whereas those communities such as Robinia pseudoacacia community, Elymus mollis community, Imperata cylindrica var. koenigii - Elymus mollis community, Carex kobomugi community, Ischaemum antephoroides community, Imperata cylindrica var. koenigii community, Phragmites communis community, Imperata cylindrica var. koenigii - Calamagrostis epigeios community occupy as band shape or patch. According to the result of the data collected and analyzed based on phytosociological method regarding 74 plots of survey area, the species composition of Daegwang sand dune vegetation is classified total 10 vegetation units comprises 7 communities and 5 groups. The 7 communities are classified into Pinus thunbergii community, Robinia pseudoacacia community, Rosa rugosa var. rugosa community, Ischaemum antephoroides community, Carex kobomugi community, Calamagrostis epigeios community, and the sub-units of Pinus thunbergii communities are classified into 3 groups of Pteridium aquilinum var. latiusculum group, Elymus mollis group, Pinus thunbergii topical group and the sub-units of Calamagrostis epigeios communities are classified into 2 groups of Phragmites communis group, Calamagrostis epigeios tipical group. The zonation of vegetation from coastal line indicated with the order of Elymus mollis - Carex kobomugi, Carex pumila, Lathyrus japonicus - Calystegia soldanella - Vitex rotundifolia, Lathyrus japonicus, Ischaemum antephoroides - Rosa rugosa var. rugosa. According to the analysis result of longitudinal section, it was found to be those types with wide width herbaceous vegetation of foredune, smooth slope of foredune, lots of dune ridges with no structure were less vulnerable to erosion of sand dune and advantageous to its recovery.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.240-246
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• 2009

Statement of problem: Insertion of endosseous implants in the atrophic maxilla is often complicated because of lack of supporting bone. Augmentation of the floor of the maxillary sinus with autogenous bone & bone substitute graft has been proven to be a reliable treatment modality, at least in the short term. The aim of this study is to evaluate the factors of implant survival rate associated with maxillary sinus lift with grafts. Material and methods: The sinus floor was augmented with bone grafts derived from modified Caldwell-luctechnique(71 subject, 93 sinus, 180 implants), the autogenous bone or autogenous+Bio-oss. Before implant installation the width and height of the alveolar crest were increased in the first stage procedure in 10 patients while in the other 61 patients augmentation and implant installation could be performed simultaneously width and height of the alveolar crest > 4 mm) or delayed installation. Results: In all case bone volume was sufficients for implant insertion. 14 of 180 inserted implants were lost during follow up and the healing period Patient received implant supported overdenture(5 patients) or fixed bridge(62 patients). Conclusion: Within the limit of the result of this study, we conclude that bone grafting of the floor of the maxillary sinus floor with bone for the insertion of implants might be a reliable treatment modality and the autogenous bone graft and delayed installation method might be the factors for good results.

• Journal of The Korean Association For Science Education
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• v.21 no.2
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• pp.264-278
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• 2001

The purpose of this study was to develop the web based instruction(WBI) program, to examine its effects on the science achievement, the attitude toward science, and students' perceptions on the WBI learning. The WBI program on the content of oceanography unit in Earth Science for high schools was developed using Namo 4.0, JAVA-script, Flash 4, Video Capture of SnagIt, Animation Shop graphic tools. The treatment group consisted of students who participated in the WBI program developed in this study, and the control group consisted of students who participated in the module instruction using self-learning materials. The results from this study were as follows: First, the scores of science achievement of WBI group were significantly higher than those of module group. There was not interaction effect of treatment and students' learning ability. Second, there were no significant difference in the scores of the attitude towards science learning between WBI group and module group, and there was not interaction effect of treatment and students' learning ability. Third, in the perception questionnaire of WBI learning, many students showed the WBI learning were good in terms of causing interaction between learners and web based learning materials including various images and animations. However there are several students who showed learning difficulties. For example they wonder which part is more important and what order is proper to study in hypertext environment.

• The Journal of the Acoustical Society of Korea
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• v.22 no.5
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• pp.375-382
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• 2003

Lip-reading technique based on bimodal is to enhance speech recognition rate in noisy environment. It is most important to detect the correct lip-image. But it is hard to estimate stable performance in dynamic environment, because of many factors to deteriorate Lip-reading's performance. There are illumination change, speaker's pronunciation habit, versatility of lips shape and rotation or size change of lips etc. In this paper, we propose the IIR filtering in time-domain for the stable performance. It is very proper to remove the noise of speech, to enhance performance of recognition by digital filtering in time domain. While the lip-reading technique in whole lip image makes data massive, the Principal Component Analysis of pre-process allows to reduce the data quantify by detection of feature without loss of image information. For the observation performance of speech recognition using only image information, we made an experiment on recognition after choosing 22 words in available car service. We used Hidden Markov Model by speech recognition algorithm to compare this words' recognition performance. As a result, while the recognition rate of lip-reading using PCA is 64%, Time-domain filter applied to lip-reading enhances recognition rate of 72.4%.

• Korea journal of population studies
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• v.19 no.2
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• pp.47-76
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• 1996

This study was carried out to provide the basic information for the implementation of population quality policies by analyzing fetal life. The outcomes and process of all the pregnancies of women with spouses living in Gapyung-gun, Kyunggi province from November 3, 1993 through December 31, 1995 were analyzed. The results of the study are as follows: According to the fetal life table, the estimated probability of pregnancy outcome showed 53.5% of live birth, 14.5% of fetal death, 32.0% of induced abortion, which resulted in 46.5% of pregnancy wastage throughout gestation period. The curve of the estimated probability of pregnancy outcome by gestation weeks showed L shape in case of total pregnancy rate, induced abortion rate and fetal death rate. The estimated probability of fetal death was 21.9% in case that the induced abortion was excluded, which was 7.4% higher than the case that induced abortion was included. The expected duration of pregnancy was 22.9 weeks until the fourth week of gestation and then started to become the highest, 26.6 weeks at the tenth week. At the 11th week, it declined to decrease to 26.4 weeks. This is attributed to the fact that the pregnancy wastage including fetal death and induced abortion occurred in the early period of pregnancy. The establishment of appropriate policies to cope with this situation are needed.

• Journal of the military operations research society of Korea
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• v.35 no.2
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• pp.33-49
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• 2009

The objective of this study is as follows. First, the hazard function on the failure probability density function of the K-1 tracked vehicles can be occurred in the form of the bathtub curve. Second, the failure mode may be different under two different operational situations. The research result shows that the bathtub curve can be fitted in the Weibull distribution, that assumes different shapes according to the specific stage of the system's life cycle. The K-1 tracked vehicle has a relatively high hazard(failure) rate at the time of its first service. The failure rate starts decreasing for a time immediately after it goes into service. After the break-in period, the surviving components have a fairly constant hazard rate. As the K-1 system ages, deterioration of its various parts takes place and the hazard rate starts Increasing. Second, the result shows the failure rate in the harsh operational environment is higher than that in the mild operational environment. In conclusion, the bathtub curve can be logically appropriate in establishing the depot overhaul cycle. Moreover, it is necessary for determining the right time of the depot overhaul to consider not only the age of defense equipment but also the different operational environment.

• School Mathematics
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• v.16 no.2
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• pp.387-407
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• 2014

Gender differences have been given major attention in mathematics education in the context of pursuing gender equity in instructional and learning environment. It had been traditional belief that male students would outperform female students in mathematics, especially in the areas as geometry. This belief has been given doubts by cumulated empirical evidences that gender differences are gradually diminishing or even reversing its direction as time goes on. In this study, gender differences in geometry were explored using TIMSS 8th grade mathematics data administered in TIMSS 2003, 2007, and 2011, based on a cognitive diagnostic modeling(CDM) approach. Among various CDM models, the Fusion model was employed. The Fusion model has advantages over other CDM models in that it provides more detailed information about gender differences at the attribute level as well as item level and more mathematically tractable. The findings of this study show that Attribute 3(Three-dimensional Geometric Shapes) revealed statistically significant gender differences favoring male students in TIMSS 2003 and 2007, but did not show significant differences in TIMSS 2011, which provides an additional empirical evidence supporting the recent observation that gender gap is narrowing. In addition to the general trends in gender differences in geometry, this study also provided affluent information such as gender differences in attribute mastery profiles and gender differences in relative contributions of each attribute in solving a particular item. Based on the findings of the CDM approach exploring gender differences, instructional implications in geometry education are discussed.

• Economic and Environmental Geology
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• v.29 no.6
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• pp.699-712
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• 1996

Field scale experiments using an automated 144-channel TDR system were conducted which monitored the movement of solute through unsaturated loamy soils. The experiments were carried out on two different field plots of 0.54 ha to study the vertical movement of solute plume created by applying a square pulse of $CaCl_2$ as a tracer. The residence concentration was monitored at 24 locations on a transect and 5 depths per location by horizontally-positioning 50 cm long triple wire TDR probes to study the heterogeneity of solute travel times and the governing transport concept at field scale. This paper describes details of experimental methodology and calibration aspects of the TDR system. Three different calibration methods for estimation of solute concentration from TDR-measured bulk soil electrical conductivity were used for each field site. Data analysis of mean breakthrough curves (BTCs) and parameters estimated using the convection-dispersion model (CDE) and the convective-lognormal transfer function model (CLT) reveals that the automated TDR system is a viable technique to study the field scale solute transport providing a normal distribution of resident concentration in a high resolution of time series, and that calibration method does not significantly affect both the shape of BTC and the parameters related to the peak travel time. Among the calibration methods, the simple linear model (SLM), a modified version of Rhoades' model, appears to be promising in the calibration of horizontally-positioned TDR probes at field condition.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.282-288
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• 2002

본 연구는 상업용 규모의 쇄미선별공정에 사용할 수 있는 파이로트 규모 원통형 홈 선별기 시작기의 설계 및 제작에 필요한 기초 연구로서, 실험실용 원통형 홈 선별기를 이용하여 쇄미선별 실험을 실시하였다. 원통 회전속도, trough각도, indent 크기와 형상, 공급량을 요인으로 하여 완전립의 수거율과 순도, 쇄립의 수거율과 순도 및 선별효율을 조사하였다. 수행한 연구결과를 요약하면 다음과 같다. 1. 선별효율에 대한 원통 회전속도와 trough각도의 단독효과 및 교호작용은 1% 수준에서 유의성이 인정되었다. 원통 회전속도가 커지면trough각도 역시 그에 따라 적절히 증가시켜야만 선별효율의 저하가 방지되는 것으로 나타났다. 2. 최고 선별효율 값은 홈의 모양과 크기, 그리고 공급량에 관계없이 낮은 회전속도 (17rpm)와 중간 trough각도 (37.5$^{\circ}$또는 60$^{\circ}$)가 조합된 처리에서 나타났으며, 60~70% 범위의 높은 값을 보였다. 선별효율에 관한 원통 회전속도와 trough각도의 최적 조합은 17rpm, 37.5$^{\circ}$라고 판단된다. 3. 말발굽형 홈과 반구형 홈 간 선별효율의 차이는 없었다. 따라서, 실제 상업용 규모의 원통형 홈 쇄미선별기 개발에 있어서는 제작이 쉽고 유지.보수가 간편한 반구형 홈을 채택하는 것이 바람직할 것으로 생각된다. 길이 2.5mm이하의 미립인 쇄미의 선별에 사용할 홈의 크기는 2.5mm 보다는 약간 큰 3.0mm 정도가 되어야만 할 것으로 판단된다. 4. 공급량에 따른 선별효율의 차이는 1% 수준에서 유의성이 인정되었으며, 공급량이 작았을 때 전반적으로 선별효율이 높았다.타리 시프터를 채택, 사용하고 있었으며, 로타리시프터 사용상의 문제는 회전몸체를 지지하는 rod spring의 파손 등 구조와 관련된 것이었다. 로타리 시프터에 의한 쇄립의 선별과 제거정도는 만족할 만한 수준은 아니었다. 4. 국내 유통백미 완전립의 길이, 폭, 두께는 각각 5.02mm, 2.93mm, 2.03mm이었으며, 산물밀도와 천립중은 각각 745.3kg/m3 및 20.46g이었다. 5. RPC 백미제품의 품질경쟁력 향상을 유도하고자 현행 쇄미의 정의와 기준을 보다 강화하여 다음과 같은 쇄미 기준과 계급을 설정, 제시하였다. "완전립" - 길이가 3.75mm이상인 미립 "준완전립" - 길이가 2.5∼3.75mm인 미립 "쇄미" - 길이가 1.75∼2.5 mm인 미립 "이물" - 길이가 1.75mm이하인 미립.볼 때 상토 종자혼합비 6 : 1, 성형롤 회전속도 약 7 rpm으로 판단되며, 이 때 제조능력은 시간당 약 65 Kg(펠렛종자 약 39,000 개), 성형률 약 87 %, 종자손실률은 약 30 %, 펠렛종자 내 평균 종자수는 약 5.5 개, 완전 벼 종자 3개 이상 포함 펠렛종자 비율은 약 100 %가 될 것으로 보인다. 세포의 Androgen 생성을 촉진시키는 역할이 있는 것으로 보여진다 따라서 옻나무 유래 F는 포유동물의 생식기능에 중요하게 작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간