• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.216-223
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• 2023

This study aimed to identify and compare the characteristics of Elymus humidus on common wheat (Triticum aestivum L. cv. Chinse Spring, CS). The seed length, width, height, and weight of E. humidus were smaller than those of the CS. In particular, the germination rate of E. humidus was substantially lower than that of CS. In the anatomical dissection of the leaf, E. humidus showed a considerably different xylem diameter of the main vascular bundle in the main vein; however, there was no difference in the phloem of the main vascular bundle compared with the xylem and phloem of the main vascular bundle in the main vein of CS, although E. humidus showed a leaf structure similar to that of CS. In addition, E. humidus had a thinner epidermis than that of CS. Regarding stomatal traits, E. humidus showed a graminoid stomata type similar to that of CS. On the adaxial and abaxial sides, the density, length, and width of the stomata in E. humidus were smaller than those in CS, whereas the distance between stomata in E. humidus was greater than that in CS. The chromosomes of E. humidus were classified as long and short based on their respective lengths. Long chromosomes were classified based on the ratio of the long arm to the short arm e.g., 1:1 or 2:1. Short chromosomes showed the same trend and some short chromosomes were microsatellites. To evaluate genetic diversity, 38 barley EST markers with polymorphisms between E. humidus and CS were selected from 236 barley EST markers.

• Journal of Environmental Science International
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• v.31 no.10
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• pp.825-832
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• 2022

This study aimed to explore companion planting to improve vegetable productivity on extensive green roofs through urban agriculture with limited substrate depth. From May to July 2021, the study conducted on the rooftop to evaluate the effects of marigold (Tagetes patula) planting ratio on the growth and pest control of cabbage (Brassica campestris). The experiment plot measured 1 m in width × 1 m in length × 0.25 m in height and 0.2 m in substrate depth. Fifteen plots were planted in varying proportions of cabbage and marigold for three repetitions per treatment: cabbage control (CC), 2:1(C₂M₁), 1:1(C₁M₁), 1:2(C₁M₂), and marigold control (MC). We found that companion planting marigolds with cabbage significantly increased cabbage growth and reduced pest infestation. The study revealed that C₁M₁, when cabbage and marigold have the same proportion, is an efficient companion planting ratio. Companion planting, in which non-crop vegetation manages pests and increases crop productivity, improves natural pest control and preserves biodiversity on rooftop urban agriculture.

• Geotechnical Engineering
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• v.14 no.5
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• pp.89-110
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• 1998

Variations of backfill load on the metal-polyethylene composite( MPC ) pipes buried in various trenches backfill afterward were investigated in this paper. The backfill loads obtained by the finite element method( FBM ) were compared with those calculated by the well-known MarstonBpangler(M-5) theory. The reliability of the finite element analysis used in this study was examined by an inaitu best for the buried pipe. The backfill lords and deflections on the real-size pipe buried on-site were measured while increasing the backfill height. In addition, further investigations were made for the variations of the backfill loads as a function of several important parameters such as the backfill soil type, bach. height$(\leq4.0m)$, diameter of the pipe$(B.$1.0m)$, and trench width($\leq 3.0 B_c$). It is confirmed that the M-S theory predicts reasonably well the backfill loafs of the MPC of the M-S backfill coils be 0.13 and 0.15 for the SC and SM coils in the D unman soil model, respectively. The load ratio, Wu-s/WwgM for a narrow trench varies negligibly with the back(111 height but fiends to increase for a wide trench. The ratio increases with increasing diameter of the pipe for a narrow trench while decreasing for a wide trench. It is also found that the ratio generally decreases as the degree of compaction increases and BM soil exhibits larger load ratio than that of SC soil.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.153-153
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• 2021

Storm Storm event is one of major issues in South Korea due to devastating damage at its landfall. A series of statistical study on the historical typhoon records consistently insist that the typhoon translation speed (TS) is on slowdown trend annually, and thus provides an urgent topic in assessing the extreme storm surge under future climate change. Even though TS has been regarded as a principal contributor in storm surge dynamics, only a few studies have considered its impact on the storm surge. The landfall angle (LA), another key physical factor of storm surge also needs to be further investigated along with TS. This study aims to elucidate the interaction mechanism among TS, LA, coastal geometry, and storm surge synthetically by performing a series of simulations on the idealized geometries using Delft3D FM. In the simulation, various typhoons are set up according to different combinations of TS and LA, while their trajectories are assumed to be straight with the constant wind speed and the central pressure. Then, typhoons are subjected to make landfall over a set of idealized geometries that have different depth profiles and layouts (i.e., open coasts or bays). The simulation results show that: (i) For the open coasts, the maximum surge height (MSH) increases with increasing TS. (ii) For the constant bed level, a typhoon normal to the coastline resulted in peak MSH due to the lowest effect of the coastal wave. (iii) For the continental shelf with different widths, the slow-moving typhoon will generate the peak MSH around a small LA as the shelf width becomes narrow. (iv) For the bay, MSH enlarges with the ratio of L/E (the length of main-bay axis /gate size) dropping, while the greatest MSH is at L/E=1. These findings suggest that a fast-moving typhoon perpendicular to the coastline over a broad continental shelf will likely generate the extreme storm surge hazard in the future, as well as the slow-moving typhoon will make an acute landfall over a narrow continental shelf.

• Journal of Oral Medicine and Pain
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• v.39 no.2
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• pp.69-77
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• 2014

Purpose: It aims to verify the applicability of existing age estimation methods derived from data of foreign population groups to Korean population groups. Moreover it is to suggest a new way applicable to practical age estimation on the basis of newly calculated regression formulae from data of Korean population groups and develop a subsidiarily applicable method to the existing method. Methods: Ratio of pulp cavity to dental crown was calculated by measuring the height and width of dental crowns and pulp cavities at the cervical line from 4,034 first and second upper molars, first and second upper premolars, first and second lower molars and first and second lower premolars on both left and right sides of 400 patients who had been treated in Dental Hospital of Yonsei University College of Dentistry, and regression equations were derived from the values of the ratio. Results: The equation with correlation coefficients the highest among females was as follows: age=$107.96-75.684{\times}{\sharp}17$ TCHI-$53.741{\times}{\sharp}26$ TCVI-$40.664{\times}{\sharp}45$ TCVI-$56.307{\times}{\sharp}46$ TCVI. Randomized anohter Korean female subjects (n=20) are applicated to the new equation. Mean of error of estimate is 10.322 years, standard deviation is 12.852 years. Minimum of error of estimate is 1.018 years, maximum is 21.365 years Conclusions: The error range of age estimation was found to be slightly wider when the existing regression formulae of Drusini were applied to Korean population groups. Also age estimation in females using the ratio of pulp cavity to dental crown measured with the length and width of dental crowns and pulp cavities from maxillomandibular molars was observed to have the highest reliability in the research. However, we consider that advanced equations of regression are needed to apply to both molars and premolars of males and females in the future.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.945-956
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• 2021

The effective growth of pepper seedlings relies on the growing period and tray used, which both aim to minimize seedling damage during the transplantation process. Therefore, the objective of this study was to evaluate the effect of red and green pepper seedling growth in plug and cylindrical paper pot (CPP) trays with different growth periods of the seedlings. Two different seedling growth trays were used for the two varieties of pepper seedlings in the same growing media. The pepper seedling growth rates were investigated at 15, 30, and 45 days for each of variety. Important parameters, e.g., the plant height, fresh weight for the plant and root, number of leaves, leaf length and width, and leaf chlorophyll contents, were measured. During the experiment, the CPP tray maintained uniform seedling growth as compared to the plug tray. CPP trays ensured the height of the seedling, with these results 0.84 to 1.6 times higher than those of the plug tray for all conditions, indicating the good quality of the pepper seedlings. The shoot and root weights were found to be greater with more leaves in the CPP tray seedlings for 45 days compared to the seedlings grown in the plug tray, whereas the green pepper variety showed a greater leaf ratio than the red pepper seedlings. The analysis of pepper seedling growth presented in this study will guide the selection of suitable growth trays and seedling periods for farmers when they undertake automatic pepper transplantation in the field.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.71-77
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• 2005

This study aims to find the safe vent area to prevent a destruction of building by gas explosion in a building. Explosion vessel which used in this experiment is 1/5 scale down model of simple livingroom and its dimension is 100cm in length 60cm in width and 45cm in height. Liquified petroleum gas(LPG) was injected to the vessel to the concentration of 4.5vol%, and injection rate were varied in 1L/min or 4L/min. Gas mixture was ignited by the 10kV electric spark. For analysis the characteristics of vented explosion pressure according to the vent size and vent shape, its size and shape were varied. From the experiment, it was found that explosion pressure in the vented explosion :in affected by the gas injection rate, vent area and vent shape. And the vent area to volume ratio(S/V) to prevent the building destruction by explosion pressure, it is recommended that the design of vent area happened by the explosion should be above 1/500cm in S/V. And if the vent area has complicate structure in same area, vented explosion pressure will be higher than a single vent, and possibility of building destruction will increase. Therefore to effectively vent the explosion pressure for protect a building and residents from the gas explosion hazards, the same vent area should have a singular and constant shape in the cross-sectional area of the vessel.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.83-92
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• 2020

A recent study to determine the fall is focused on analyzing fall motions using a recurrent neural network (RNN), and uses a deep learning approach to get good results for detecting human poses in 2D from a mono color image. In this paper, we investigated the improved detection method to estimate the position of the head and shoulder key points and the acceleration of position change using the skeletal key points information extracted using PoseNet from the image obtained from the 2D RGB low-cost camera, and to increase the accuracy of the fall judgment. In particular, we propose a fall detection method based on the characteristics of post-fall posture in the fall motion analysis method and on the velocity of human body skeleton key points change as well as the ratio change of body bounding box's width and height. The public data set was used to extract human skeletal features and to train deep learning, GRU, and as a result of an experiment to find a feature extraction method that can achieve high classification accuracy, the proposed method showed a 99.8% success rate in detecting falls more effectively than the conventional primitive skeletal data use method.

• Geomechanics and Engineering
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• v.31 no.4
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• pp.375-384
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• 2022

The variation of the undrained shear strength (c_u) is an important consideration for assessing slope stability in engineering practice. Previous studies focused on the three-dimensional (3D) stability of slopes in normally consolidated clays generally assume the undrained shear strength increases linearly with depth but does not vary in the horizontal direction. To assess the 3D stability of slopes with spatially varying undrained shear strength, the kinematic approach of limit analysis was adopted to obtain the upper bound solution to the stability number based on a modified failure mechanism. Three types failure mechanism: the toe failure, face failure and below-toe failure were considered. A serious of charts was then presented to illustrate the effect of key parameters on the slope stability and failure geometry. It was found that the stability and failure geometry of slopes are significantly influenced by the gradient of c_u in the depth direction. The influence of c_u profile inclination on the slope stability was found to be pronounced when the increasing gradient of c_u in the depth direction is large. Slopes with larger width-to-height ratio B/H are more sensitive to the variation of c_u profile inclination.

• Wind and Structures
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• v.25 no.3
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• pp.233-259
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• 2017

Investigations on simulated near-surface atmospheric boundary layer (ABL) in an open-jet facility are carried out by conducting experimental tests on small-scale models of low-rise buildings. The objectives of the current study are: (1) to determine the optimal location of test buildings from the exit of the open-jet facility, and (2) to investigate the scale effect on the aerodynamic pressure characteristics. Based on the results, the newly built open-jet facility is well capable of producing mean wind speed and turbulence profiles representing open-terrain conditions. The results show that the proximity of the test model to the open-jet governs the length of the separation bubble as well as the peak roof pressures. However, test models placed at a horizontal distance of 2.5H (H is height of the wind field) from the exit of the open-jet, with a width that is half the width of the wind field and a length of 1H, have consistent mean and peak pressure coefficients when compared with available results from wind tunnel testing. In addition, testing models with as large as 16% blockage ratio is feasible within the open-jet facility. This reveals the importance of open-jet facilities as a robust tool to alleviate the scale restrictions involved in physical investigations of flow pattern around civil engineering structures. The results and findings of this study are useful for putting forward recommendations and guidelines for testing protocols at open-jet facilities, eventually helping the progress of enhanced standard provisions on the design of low-rise buildings for wind.