• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.83-88
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• 2016

In this study, previously reported surplus solar energy-related study result and current status of fan coil unit (FCU) for cooling and heating installed in the current sites were briefly examined and then a method to determine the number of FCUs required to recover surplus solar energy was schematically proposed to provide basic data for researchers and technical engineers in this field. The maximum, mean, and minimum outside temperatures during the experiment period were about $28.2^{\circ}C$, $4.4^{\circ}C$, and $-11.5^{\circ}C$, respectively. The horizontal surface solar radiation level outside the greenhouse was in a range of $0.8-20.5MJ{\cdot}m^{-2}$ and mean and total solar radiation were $10.8MJ{\cdot}m^{-2}$ and $1,187.5MJ{\cdot}m^{-2}$. The mean temperature and relative humidity in the greenhouse during the daytime were in a range of 18.8-45.5 and 53.5-77.5%. The total surplus solar energy recovered from the greenhouse during the experiment period was approximately 6,613.4MJ, which could supplement about 6.7% of the total heating energy 98,600.2 MJ. In addition, the number of FCUs installed for heating varies case to case, although similar FCUs are used. Thus, it is necessary to study the installation height, orientation and installation distance as well as the appropriate number of FCUs from the efficient and economical viewpoints. The required numbers of FCUs for surplus solar energy recovery were 8.4-10.9units and 6.1-8.0units based on air mass and circular flow rate that passed through the FCUs. Considering calculation methods and the risks such as efficiency and use environments of FCUs, it was found that about nine units (one unit per $24m^3$ approximately) needed to be installed. The required number of FCUs for surplus solar energy recovery was around one unit per $24m^3$ approximately.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.1
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• pp.35-41
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• 2007

Purpose: To evaluate the effectiveness of a simple and practical shielding device to reduce the fetal dose for a pregnant patient undergoing radiation therapy of brain metastasis. Materials and Methods: The dose to the fetus was evaluated by simulating the treatments using the anthropomorphic phantom. The prescription dose at mid-brain is $300cGy{\times}10$ fractions with 6 MV photon with $18{\times}22cm^2$ field size. The additional shielding devices to reduce the fetal dose are a shielding wall, cerrobend plates and lead (Pb) sheets over acrylic bridge. Various points of measurement with off-field distance were detected by using ion-chamber (30, 40, 50, and 60 cm) with and without the shielding devices and TLD (30, 40, 50, 60, and 70 cm) only with the shielding devices. Results: The doses to the fetus without shielding were 3.20, 3.21, 1.44, 0.90 cGy at the distances of 30, 40, 50, and 60 cm from the treatment field edge. With shielding, the doses were reduced to 0.88, 0.60, 0.35, 0.25 cGy, and the ratio of the shielding effect varied from 70% to 80%. TLD results were 1.8, 1.2, 0.8, 1.2, and 0.8 cGy (70 cm). The total dose to the fetus was expected to be under 1 cGy during the entire treatment. Conclusion: The essential point during radiation therapy of pregnant patient would be minimizing the fetal dose. 10 cGy to 20 cGy is the threshold dose for fetal radiation effects. Our newly developed device reduced the fetal dose far below the safe level. Therefore, our additional shielding devices are useful and effective to reduce the fetal dose.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.6
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• pp.98-109
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• 2011

Habitat restoration initiative is an important factor for the on-site preservation of butterflies. A new habitat necessitates the investigation of the ecology of the butterfly, the landscape of the habitat, the work process, and a cost analysis. In this study, these factors were analyzed through1) re-consideration of the secured results from three years of field work, and 2) a habitat area estimation conducted according to the presence or absence of larvae and adults via a Parnassius bremeri Bremer survey. The investigation of the natural habitat, done for both larvae and adult butterflies found in South Korea, suggested that multiple patches with a minimum size exceeding $300m^2$ and with an average size of about $1,600m^2$were required for survival of this butterfly. Therefore, more than five patches should be considered for butterfly habitat and patches should have similarity to the present habitat environment with transplantation plans for diet plants and honeydew plants. In addition, to activate the migration of the butterfly, cutting down trees that are obstacles to migration, minimizing the distance between patches and the addition of a stepping patch are also required. A patch connectivity analysis showed that patches should be located within 300m of neighboring patches, as the migration of the butterfly will fail if it is more than 600m. Additionally, more than $10,000m^2$ for a single patch or a patch network composed more than five patches over $1,600m^2$ in size were recommended, with a total patch size of $8,000m^2$. Additionally, neighboring multiple patch networks are more desirable than a single habitat in the event a cyclic habitat pattern arises. In this study, we suggest a habitat restoration and optimal prerequisites for a butterfly habitat. It is expected that this research will lead to the creation of a good model for the restoration of butterfly species.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.3
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• pp.147-154
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• 2011

Decision making in Environmental Impact Assessment (EIA) and Consultation on the Coastal Area Utilization (CCAU) is footing on the survey reports, thus requires concrete and accurate information on the natural habitats. In spite of the importance of reporting the ecological quality and status of habitats, the accumulated knowledge and recent techniques in ecology such as the use of investigated cases and indicators/indices have not been utilized in evaluation processes. Even the EIA report does not contain sufficient information required in a decision making process for conservation and development. In addition, for CCAU, sampling efforts were so limited that only two or a few stations were set in most study cases. This hampers transferring key ecological information to both specialist review and decision making processes. Hence, setting the effective number of sampling stations can be said as a prior step for better assessment. We introduced a few statistical techniques to determine the number of sampling stations in macrobenthos surveys. However, the application of the techniques requires a preliminary study that cannot be performed under the current assessment frame. An analysis of the spatial configuration of sampling stations from 19 previous studies was carried out as an alternative approach, based on the assumption that those configurations reported in scientific journal contribute to successful understanding of the ecological phenomena. The distance between stations and number of sampling stations in a $4{\times}4$ km unit area were calculated, and the medians of each parameter were 2.3 km, and 3, respectively. For each study, approximated survey area (ASA, $km^2$) was obtained by using the number of sampling stations in a unit area (NSSU) and total number of sampling stations (TNSS). To predict either appropriate ASA or NSSU/TNSS, we found and suggested statistically significant functional relationship among ASA, survey purpose and NSSU. This empirical approach will contribute to increasing sampling effort in a field survey and communicating with reasonable data and information in EIA and CCAU.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.3
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• pp.180-190
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• 2014

It has been customary to exclude top 10-20% of velocity profiles in the Acoustic Doppler Current Profiler (ADCP) measurement due to side lobe effects at the boundary. To better understand the mixing in the Yeongsan estuary, the freshwater advection speed (FAS) was recovered from highly contaminated ADCP data near the surface. The velocity profiles were measured by using ADCP at two stations in the Yeongsan estuary during August 2011: one was located in front of the Yeongsan estuarine dam and the other was deployed near Goha Island. The FAS was recovered from the ADCP data set by applying rigorous post-processing methods and compared with the sediment advection speed (SAS). The SAS was determined by the peak time difference of suspended sediment concentration between two stations in the channel, divided by the distance of two stations. The FAS and the SAS showed very similar value when the freshwater discharge was greater than $2.0{\times}10^7$ ton and the SAS was a bit greater when the freshwater discharge was smaller. Since the FAS was on average about 0.8 m/s greater than the velocity at 0.8 of water depth from the bottom, the net discharge, estimated with recovered FAS and integrated over water depth and tidal cycle, was directed seaward during the high discharge contrary to the onshore direction of the net discharge estimated with 0.8 of water depth from the bottom. Moreover, the velocity shear and Richardson number changed when the FAS was used. Thus, the importance of the true FAS is appreciated in the investigation of the surface layer stability. If currents, temperature and salinity were observed for longer time in the future, it could be possible to more accurately understand the formation and decay of stratification as well as the suspended sediment transport processes.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.199-206
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• 2004

Factors of universal soil loss equation, USLE, and its revised version, RUSLE for Korean soils were reevaluated to estimate the national scale of soil loss based on digital soil maps. Rainfall erosivity factor, R, of 158 locations of cities and counties were spacially interpolated by the inverse distance weight method. Soil erodibility factor, K, of 1321 soil phases of 390 soil series were calculated using the data of soil survey and agri-environmental quality monitoring. Topographic factor, LS, was estimated using soil map of 1:25,000 scale with soil phase and land use type. Cover management factor, C, of major crops and support practice factor, P, were summarized by analyzing the data of lysimeter and field experiments for 27 years (1975-2001) in the National Institute of Agricultural Science and Technology. R factor varied between 2322 and 6408 MJ mm $ha^{-1}$ $yr^{-1}$ $hr^{-1}$ and the average value was 4276 MJ mm $ha^{-1}$ $yr^{-1}$ $hr^{-1}$. The average K value was evaluated as 0.027 MT hr $MJ^{-1}$ $mm^{-1}$. The highest K factor was found in paddy rice fields, 0.034 MT hr $MJ^{-1}$ $mm^{-1}$, and K factors in upland fields, grassland, and forest were 0.026, 0.019, and 0.020 MT hr $MJ^{-1}$ $mm^{-1}$, respectively. C factors of upland crops ranged from 0.06 to 0.45 and that of grassland was 0.003. P factor varied between 0.01 and 0.85.

• Journal of Animal Science and Technology
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• v.53 no.1
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• pp.1-6
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• 2011

This simulation study was performed to investigate the accuracy of the estimated breeding value by using genomic information (GEBV) by way of Bayesian framework. Genomic information by way of single nucleotide polymorphism (SNP) from a chromosome with length of 100cM were simulated with different marker distance (0.1cM, 0.5cM), heritabilities (0.1, 0.5) and half sibs families (20 heads, 4 heads). For generating the simulated population in which animals were inferred to genomic polymorphism, we assumed that the number of quantitative trait loci (QTL) were equal with the number of no effect markers. The positions of markers and QTLs were located with even and scatter distances, respectively. The accuracies of estimated breeding values by way of indicating correlations between true and estimated breeding values were compared on several cases of marker distances, heritabilities and family sizes. The accuracies of breeding values on animals only having genomic information were 0.87 and 0.81 in marker distances of 0.1cM and 0.5cM, respectively. These accuracies were shown to be influenced by heritabilities (0.87 at $h^2$ =0.10, 0.94 at $h^2$ =0.50). According to half sibs' family size, these accuracies were 0.87 and 0.84 in family size of 20 and 4, respectively. As half sibs family size is high, accuracy of breeding appeared high. Based on the results of this study it is concluded that the amount of marker information, heritability and family size would influence the accuracy of the estimated breeding values in genomic selection methodology for animal breeding.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.279-285
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• 2019

To estimate daily canopy photosynthesis, accurate estimation of canopy light interception according to a daily solar position is needed. However, this process needs a lot of cost, time, manpower, and difficulty when measuring manually. Various modeling approaches have been applied so far, but it was difficult to accurately estimate light interception by conventional methods. The objective of this study is to estimate the spatial distributions of light interception and photosynthetic rate of paprika with time by using 3D-scanned plant models and optical simulation. Structural models of greenhouse paprika were constructed with a portable 3D scanner. To investigate the change in canopy light interception by surrounding plants, the 3D paprika models were arranged at $1{\times}1$ and $9{\times}9$ isotropic forms with a distance of 60 cm between plants. The light interception was obtained by optical simulation, and the photosynthetic rate was calculated by a rectangular hyperbola model. The spatial distributions of canopy light interception of the 3D paprika model showed different patterns with solar altitude at 9:00, 12:00, and 15:00. The total canopy light interception decreased with an increase of surrounding plants like an arrangement of $9{\times}9$, and the decreasing rate was lowest at 12:00. The canopy photosynthetic rate showed a similar tendency with the canopy light interception, but its decreasing rate was lower than that of the light interception due to the saturation of photosynthetic rate of upper leaves of the plants. In this study, by using the 3D-scanned plant model and optical simulation, it was possible to analyze the light interception and photosynthesis of plant canopy under various conditions, and it can be an effective way to estimate accurate light interception and photosynthesis of plants.

• The Journal of Engineering Geology
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• v.31 no.1
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• pp.103-118
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• 2021

For management and preservation measures of lava tube, it is studied how the blasting vibration by constructions near Geomunoreum lava tubes in Jeju affect lava tube. 11 boreholes were drilled in study area, and in-situ blasting tests were conducted by changing from 0.5 kg to 10 kg charge per delay in those boreholes. The vibration velocity, which meets the regulatory vibration criterion during daytime, was estimated as below 0.276 cm/sec by analyzing the relationship between vibration velocity and vibration level. In addition, SRE and CRE were calculated from the results of in-situ blasting tests, and k-values were shown as 130.04 in SRE, 199.71 in CRE, respectively. Also, n-values were shown as -1.717 in SRE, -1.711 in CRE, respectively. Charge per delay were assessed based on these equations, and charges per delay had ranges of 0.57~7.42 kg/delay in estimation equation of vibration velocity, 0.21~5.29 kg/delay in SRE, and 0.04~5.51 kg/delay in CRE, considering the 0.2 kine vibration criterion for cultural heritage and the 20~100 m distance from vibration source. Additionally, the relationships which meet the criteria of 0.2 kine, were calculated by combining CRE in this study with the result of previous study. Allowable charges per delay, which meet the criteria of 0.2 kine, were evaluated as 1.07 kg/delay in 50 m, 5.13 kg/delay in 100 m and 22.26 kg/delay in 200 m distances. These relationships for each vibration velocity are useful to deduce charge per delay for the ground near Geomunoreum lava tube.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.105-131
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• 2022

Even after the improvement in 2019, UNCTAD's Liner Shipping Connectivity Index (LSCI), which evaluates the performance of the global container port market, has limited use. In particular, since the liner shipping connectivity index evaluates the performance based only on the distance of the relationship, the performance index combining the port attractiveness of calling would be more efficient. This study used the modified Huff model, the hub-authority algorithm and the eigenvector centrality of social network analysis, and correlation analysis for 2007, 2017, and 2019 data of Ocean-Commerce, Japan. The findings are as follows: Firstly, the port attractiveness of calling and the overall performance of the port did not always match. However, according to the analysis of the attractiveness of a port calling, Busan remained within the top 10. Still, the attractiveness among other Korean ports improved slowly from the low level during the study period. Secondly, Global container ports are generally specialized for long-term specialized inbound and outbound ports by the route and grow while maintaining professionalism throughout the entire period. The Korean ports continue to change roles from analysis period to period. Lastly, the volume of cargo by period and the extended port connectivity index (EPCI) presented in this study showed a correlation from 0.77 to 0.85. Even though the Atlantic data is excluded from the analysis and the ship's operable capacity is used instead of the port throughput volume, it shows a high correlation. The study result would help evaluate and analyze global ports. According to the study, Korean ports need a long-term strategy to improve performance while maintaining professionalism. In order to maintain and develop the port's desirable role, it is necessary to utilize cooperation and partnerships with the complimentary port and attract shipping companies' services calling to the complementary port. Although this study carried out a complex analysis using a lot of data and methodologies for an extended period, it is necessary to conduct a study covering ports around the world, a long-term panel analysis, and a scientific parameter estimation study of the attractiveness analysis.