• Journal of Ecology and Environment
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• 제41권11호
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• pp.310-317
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• 2017

Background: Many studies about climate-related range shift of plants have focused on understanding the relationship between climatic factors and plant distributions. However, consideration of adaptation factors, such as dispersal and plant physiological processes, is necessary for a more accurate prediction. This study predicted the future distribution of marlberry (Ardisia japonica), a warm-adapted evergreen broadleaved shrub, under climate change in relation to the dispersal ability that is determined by elapsed time for the first seed production. Results: We introduced climate change data under four representative concentration pathway (RCP 2.6, 4.5, 6.0, and 8.5) scenarios from five different global circulation models (GCMs) to simulate the future distributions (2041~2060) of marlberry. Using these 20 different climate data, ensemble forecasts were produced by averaging the future distributions of marlberry in order to minimize the model uncertainties. Then, a dispersal-limited function was applied to the ensemble forecast in order to exam the impact of dispersal capacity on future marlberry distributions. In the dispersal-limited function, elapsed time for the first seed production and possible dispersal distances define the dispersal capacity. The results showed that the current suitable habitats of marlberry expanded toward central coast and southern inland area from the current southern and mid-eastern coast area in Korea. However, given the dispersal-limited function, this experiment showed lower expansions to the central coast area and southern inland area. Conclusions: This study well explains the importance of dispersal capacity in the prediction of future marlberry distribution and can be used as basic information in understanding the climate change effects on the future distributions of Ardisia japonica.

• 한국환경복원기술학회지
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• 제6권5호
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• pp.59-69
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• 2003

Most denuded mountain areas in Korea were completely stabilized by the successful work of the 1st and 2nd 10-year Forest Development Plans which targeted the reforestation of denuded forest lands. The objectives of this study are (1) to estimate the depth of organic horizon in the soil profile, (2) to investigate the change of vegetation structure, (3) to estimate the change of biomass in the erosion controlled and rehabilitated mountain areas with the passage of time. This study was carried out as the 5th times. The first study began in the year of 1985, the second study was in the year of 1988, the third study was in the year of 1992, 4th was in the year of 1998 and 5th was in the year of 2002. The first study started in the study sites which elapsed 9 years after erosion control works. The results of the study were as follows : The increase rate of soil thickness was estimated to $Y_{(cm)}=2.906log_{(yr)}-3.2476(r^2=0.917)$ during 26 years after erosion control works. The important value of pines decreased to 14.7% on upper layer. But, the important value of alders. which did not plant on erosion control work increased to 27.1%. The decrease of whole crown projection indicates that pines. and alders were heavily injured by pine leaf gall midge in the year of 1993, 1995 years and Agelastica coerulea Baly in the year of 1986, 1987 years at Yoju-gun. The young growth of pines and alders not appeared on the soil surface which elapsed 26 years after erosion control works. On the lower layer, oaks occupied over 50% in I.V, RD, RC, RF. In process of years, the increase of biomass estimated to be $Y_{(t/ha)}={0.7505X_{(yr)}}^{1.6335}\;(r^2=0.9712)$ for 26 years after erosion control works.

• Restorative Dentistry and Endodontics
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• 제9권1호
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• pp.7-14
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• 1983

The purpose of this study was to investigate pulpal responses to tricalcium phosphate and durapatite which recently introduced as a bone substitute. Tricalcium phosphate and durapatite were placed on the amputated pulp tissue in the dog's teeth. Animals were sacrificed after 1, 2, 3 and 4 weeks and specimens were decalcified, embedding, sectioned and stained routinly. Microscopic examination reveals as follows; 1. Tricalcium phosphate: Severe inflammatory change was seen in the all cases and calcified masses were seen at 2 weeks. Calcified masses were enlarged according to the time elapsed. 2. Durapatite: Severe inflammatory change and pus cavities were found at 1 week. There was no evidence of healthy cell component in the remaining pulp tissue and degenerative change was obvious at 2, 3 and 4 weeks. 3. Dentin bridge was not formed in the both cases. In the case of tricalcium phosphate osteoblasts were observed unevenly around the calcified masses which were composed of hematophilic substance in central portion and eosinophilic substance in peripheral region of the masses.

• 한국토양비료학회지
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• 제46권5호
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• pp.359-364
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• 2013

This study was conducted to develop a model to estimate crop leaf surface temperature. The results were as following; A definition for the daily time based on elapsed time from the midnight (00:00) as "E&E time" with the unit of Kmin. was suggested. The model to estimate the scaled temperature ($T^*e$) of crop leaf surface temperature by scale factor ($T^*$) according to the "E&E time : Kmin."(X) was developed as eq. (1) $T^*e=0.5{\cdot}sin(X+780)+0.5$ (2) $T^*=(Tx-Tn)/(Tm-Tn)$, Tx : Daily leaf temperature, Tm : Daily maximum leaf temperature, Tn : Daily minimum leaf temperature. Relative sensitivity of the measured temperature compared to the estimated temperature of red pepper, soybean and persimmon was 1.078, 1.033 and 0.973, respectively.

• Agricultural and Biosystems Engineering
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• 제1권1호
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• pp.38-42
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• 2000

Though the freshness for agricultural products is an important factor related to their quality management, this terminology is being used restrictedly because it is very subjective. In this study, a dimensionless index which had the span of the maximum of 1 through the minimum of 0 was proposed to describe freshness of the product with time-variant quality and was applied to Tsugaru and Fuji apples. First, the compressive properties having the linearity in their change regarding time elapsed after harvest were selected. For Tsugaru apple, bio-yield and rupture forces had high correlation with time while for Fuji, bio-yield and rupture deformations had high correlations. When the slope, or ratio of force to deformation, was considered, the effect of cultivar could be neglected. When the linearly time-variant compressive properties for Tsugaru and Fuji apples were involved in the freshness indices, they described well freshness of apples. Also, the freshness decay constant depicted a characteristic which related to freshness decay rate. Therefore, the freshness index can be utilized to manage the quality during storage and distribution of apples.

• 대한치과교정학회지
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• 제46권3호
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• pp.129-136
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• 2016

Objective: To investigate the dimensional accuracy of digital dental models obtained from the dental cone-beam computed tomography (CBCT) scan of alginate impressions according to the time elapse when the impressions are stored under ambient conditions. Methods: Alginate impressions were obtained from 20 adults using 3 different alginate materials, 2 traditional alginate materials (Alginoplast and Cavex Impressional) and 1 extended-pour alginate material (Cavex ColorChange). The impressions were stored under ambient conditions, and scanned by CBCT immediately after the impressions were taken, and then at 1 hour intervals for 6 hours. After reconstructing three-dimensional digital dental models, the models were measured and the data were analyzed to determine dimensional changes according to the elapsed time. The changes within the measurement error were regarded as clinically acceptable in this study. Results: All measurements showed a decreasing tendency with an increase in the elapsed time after the impressions. Although the extended-pour alginate exhibited a less decreasing tendency than the other 2 materials, there were no statistically significant differences between the materials. Changes above the measurement error occurred between the time points of 3 and 4 hours after the impressions. Conclusions: The results of this study indicate that digital dental models can be obtained simply from a CBCT scan of alginate impressions without sending them to a remote laboratory. However, when the impressions are not stored under special conditions, they should be scanned immediately, or at least within 2 to 3 hours after the impressions are taken.

• 한국가축번식학회지
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• 제5권1호
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• pp.43-63
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• 1981

This study aimed to determine the effects of adrenalectomy on the sexual gland, the thyroid gland and the serum components. A total of 192 Wister strain albino rats were evenly divided into 4 sexually equal groups for the comparisons. Each groups was divided into a control and a treatment group by sexuality. Each tissue of the sexual gland and the thyroid gland was microscopically examined, and at the same time body weight and serum components were also examined on the 1st, 7th, 14th, 28th, 42nd, 56th, 70th and 84th day respectively following adrenalectomy. The results obtained were as follows: 1. The body weight was sufficiently retarded in decreasingly after the adrenalectomy as compared to that of control. 2. The histological change of testis started atrophy of spermatogonia and degeneration of spermatocyte. There was a, pp.ared no cell division activity. Spermatozoa in the seminiferous tuble was not noticed but degeneration of interstitial cell was started and spermatozoa in the epididymal duct disa, pp.ared. 3. Degeneration of oocyte and follicular cell was noticed as the histological change of ovary. There was not a, pp.arance of primary follicle and corpus Iuteum but interstitial cell was proliferated. 4. For the effect of adrenalectomy on the histological change of the thyroid gland, the number of small follicle decreased and that of large follicle increased as the time passed following the adrenalectomy. And the follicular epithelial cell became squamous as typical condition of functional decreased. 5. It was shown that in the total contents of serum protein no difference with control occurred with in the 70th day for male and female adrenalectomized, respectively. But the differences in protein contents were significanly decreased on the 70th day. 6. No difference occurred in the total serum lipids on the 7th day, but they decreased significantly on the 42nd day, and (P<0.01) on the 56th, and 70th day. A tendency to decrease was noted as time elapsed following adrenalectomy. 7. Increase and decrease were intercrossed in the serum cholesterol contents between the control and th treatment groups on the 28th day. But the difference significantly decreased on the 42nd, 56th, and 70th day after adrelalectomized. The contents showed tendency to decrease as time elapsed following adrenalectomy. 8. The blood glucose contents rapidly decreased with time. The difference were significant on the 28th and 42nd day, and highly significant on the 56th and 70th day for male adrenalectomized. 9. In case of solium, there was no noticeable sexual distinction. There was slight in creasing or decreasing for the control group. But the treatment group tended continuously to decrease for male and female. 10. It was shown that potassium contents tended to increase on the 28th day for male and female, but the differences were small. 11. As for chlorine, it tended to decrease rapidly on 7th day for male and female adrenalectomized, and the tendency continued.

• Journal of the Korean Wood Science and Technology
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• 제36권1호
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• pp.30-35
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• 2008

동해안 지역에서 산불로 고사된 소나무의 5년에 걸친 경시적 재질 변화를 역학성능을 중심으로 조사하였다. 고사에 따른 재질열화로 가장 크게 영향 받는 역학성능은 충격 휨 흡수에너지였다. 따라서 고사 초기의 재질변화를 예측하는 지표로 활용이 가능할 것으로 밝혀졌다. 고사 경과에 따라 변재의 재질열화가 심재에 비해 두드러지게 진행되었다. 열화의 정도는 충격 휨 흡수에너지가 가장 컸으며 압축강도가 가장 작았다. 고사 이후의 외관 변화와 역학성능의 열화진행 정도로 볼 때 산불피해 소나무의 유효한 활용을 위한 적정 벌채 시기는 산불발생 1년 이내가 바람직한 것으로 밝혀졌다.

• 한국군사과학기술학회지
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• 제16권2호
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• pp.169-174
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• 2013

In counterfire warfare, it is important to detect and attack enemy targets faster than the enemy using sensing The grided environmental data is usually provided by the numerical simulation coupled with a data assimilation technique and various inter- or extrapolation algorithms, both of which are based on the observation spanning from simple equipments to satellites. In order to employ the gridded environmental data in the M&S system frequently cutting area and changing its resolution, interpolation algorithms such as linear, cubic spline, IDW, and Kriging methods are necessary to apply. These methods, however, require much time in the M&S system. This paper introduces a technic to reduce time to change the resolution of data. using the binary search method, which finds a point to interpolate quickly and interpolate data in the vicinity of. We also show the efficiency of proposed methods by way of measuring the respective elapsed times.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.73-74
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• 2005

Shipping company and operators have to manage well to keep shipping schedules without problems in main engine. Specially operators have to operate main engine within the limit of operation point, and adjust related parameters to be operated safely and continuously. Also operators have ability to analyze fouling condition of hull through comparing data gotten from P-V curve and performance results of new building ships in trial with service ships. In this study, not only compared main engine performance results in shop trial and sea trial, but also investigated performance trend in accordance with the time elapsed for the service ship's diesel engine. They were confirmed as follows. First, shop trial load is higher than sea trial load but ship's speed is satisfied with owner's contract speed. Second as time goes by, load of service ship increases steadily and other parameters related with main engine shows variable change depend on main engine load increasing.