• Journal of Korea Water Resources Association
• /
• v.56 no.4
• /
• pp.235-243
• /
• 2023

Due to the revision of the River Act and the enactment of the Act on the Investigation, Planning, and Management of Water Resources, a regular bed change survey has become mandatory and a system is being prepared such that local governments can manage water resources in a planned manner. Since the topography of a bed cannot be measured directly, it is indirectly measured via contact-type depth measurements such as level survey or using an echo sounder, which features a low spatial resolution and does not allow continuous surveying owing to constraints in data acquisition. Therefore, a depth measurement method using remote sensing-LiDAR or hyperspectral imaging-has recently been developed, which allows a wider area survey than the contact-type method as it acquires hyperspectral images from a lightweight hyperspectral sensor mounted on a frequently operating drone and by applying the optimal bandwidth ratio search algorithm to estimate the depth. In the existing hyperspectral remote sensing technique, specific physical quantities are analyzed after matching the hyperspectral image acquired by the drone's path to the image of a surface unit. Previous studies focus primarily on the application of this technology to measure the bathymetry of sandy rivers, whereas bed materials are rarely evaluated. In this study, the existing hyperspectral image-based water depth estimation technique is applied to rivers with vegetation, whereas spatio-temporal hyperspectral imaging and cross-sectional hyperspectral imaging are performed for two cases in the same area before and after vegetation is removed. The result shows that the water depth estimation in the absence of vegetation is more accurate, and in the presence of vegetation, the water depth is estimated by recognizing the height of vegetation as the bottom. In addition, highly accurate water depth estimation is achieved not only in conventional cross-sectional hyperspectral imaging, but also in spatio-temporal hyperspectral imaging. As such, the possibility of monitoring bed fluctuations (water depth fluctuation) using spatio-temporal hyperspectral imaging is confirmed.

• Journal of agriculture & life science
• /
• v.50 no.1
• /
• pp.273-281
• /
• 2016

In this study, after carrying out a bending test that targeted the frames of plastic film greenhouse, the load-displacement relationship was analyzed to be used as basic data to develop greenhouse construction and maintenance guidelines. As a result, regardless of the shapes of the specimen, the yield and the maximum load increased as the size of the specimen increased. The displacement also showed the same pattern. A steel pipe showed lower yield and maximum load than a square pipe, and the displacement was large. In the steel pipe case, the displacement under the yield and maximum load was in the range of approximately 1.42-4.20mm and 5.80-24.13mm, respectively. In the square pipe case, the displacement under the yield and maximum load was in the range of approximately 1.62-3.00mm and 3.13-8.01mm, respectively. Further, a large difference was observed between the result of this test and the values calculated by a conventionally provided standard. In particular, not much difference was found from the result of this test in the case of a purlin member from the values provided by previous researches. However, a large difference was observed in the column or main rafter members. Furthermore, when a wide-span and venlo type, which is a glasshouse, was used as a target(h/100 and h/80), the displacement under the yield and maximum load was approximately 28.0mm and 35.0mm, respectively, which showed a large difference compared with the Netherlands standard(14.0mm) of a glasshouse. Further, in the main rafter case, a large difference was observed in the displacement limit according to the width(i.e., span) of the greenhouse where members are used. Therefore, because the displacement limit can vary depending on various factors such as type, form, and size of a greenhouse, we determined that studies or tests that consider these factors should be carried out to reflect them in the construction and maintenance of greenhouses.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.4
• /
• pp.24-36
• /
• 2022

The Bonghwang-dong ruins in Gimhae, the central area of Geumgwan Gaya, is presumed to be the site of the royal palace, and excavations have been in progress at the Gaya National Cultural Heritage Research Institute. According to a research conducted by lowering the level to the base layer on the north side of the site, mostly shell layers composed of oysters were confirmed, and soil composed of different material was alternately filled in to form a site construction. In other words, it can be seen that there was work at the site of the Bonghwang-dong ruins that required large-scale labor, such as building ramparts and embankments. There is stratigraphic confusion such as showing different age values in the same shell layer through a chronological analysis of organic matter and charcoal in the sedimentary layer, and deriving a result value in the upper layer ahead of the lower layer. In addition, open-sea diatoms are observed not only in the sedimentary layers, but also the pits. Therefore, it is judged that the soil constituting the ruins was brought from the outside. The Bonghwang-dong ruins are located inside the commonly called Bonghwang earthen ramparts, where many excavation organizations conducted research within the estimated range of the earthen fortifications. As a result, it was found that it was similar to the sedimentary layers of the ruins of the Three Kingdoms Period, which were investigated along with the ruins of Bonghwang-dong. Through this, the surrounding ruins, including those of Bonghwang-dong, were located close to paleo-Gimhae Bay, so it is believed that the soil brought from the surroundings was used to reinforce the ground. As a result of the excavation research on the Bonghwang-dong ruins conducted so far, it was found by sedimentary layer analysis and soil experiments that the ruins were created on stable land. Relics excavated in the sediments of the ruins and carbon dating data show that Bonghwang-dong carried out large-scale civil construction work in the 4th century to build the site, which clearly shows the status of Geumgwan Gaya.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.4
• /
• pp.138-164
• /
• 2022

The Neolithic shell midden in Daejuk-ri, Seosan, is distributed on the gentle slope of a low hill close to the west coast. The bedrock of the area consists mainly of schist with various mafic minerals, but shows a partial gneiss pattern. The site consists of loamy topsoil and clay loam subsoil, and the degree of siallization is relatively low. Although the pottery excavated from the shell midden shares mostly similar features, a variety of shapes and patterns coexist. The surface colors, thickness and physical properties are slightly different. The pottery can be subdivided into three types (IA, IB and II) according to the composition of the body clay, the temper and the existence of a black core. Types IA and IB are colorless mineral pottery with a non-black or black core respectively. TypeII is colored mineral pottery with a non-black core. Type I pottery also contains non-plastic colored minerals, but type II contains a large amount of biotite, chlorite, talc, amphibole, diopside and tremolite, which include a large amount of Mg and Fe. The studied pottery contains a small amount of organic matter. Considering the grain size and relatively poor sorting and roundness of the non-plastic particles, the pottery appears to be made by adding coarse non-plastic tempers for special purposes to the untreated weathered soil around the site. The three types of pottery seem to have been incompletely fired in general. While type IB has the lowest degree of oxidation, typeII shows the highest degree of redness and oxidation. It can be interpreted that these differences depend on the firing temperature and the ratio of non-plastic particles. Through a synthesis of the minerals, geochemical data and thermal history, it can be determined that the firing temperature ranged from 600 to 700℃. The pottery types of the Daejuk-ri Shell Midden have slightly different production conditions, mineral compositions, and physical properties, but have undergone similar production processes with basically the same clay materials. The clay is almost identical to the composition of the bedrock and weathered soil distributed in the Daejuk-ri area. Currently, there is an industrial complex in the area, so it is difficult to confirm the soil and geological distribution of the site. However, it is highly probable that the area around the site was self-sufficient for the clay and tempers required for the production of the Neolithic pottery. Therefore, it can be interpreted that the group that left the shell midden in Daejuk-ri lived near the site, visited the site for the purpose of collecting and processing shellfish, and discarded the broken pottery along with shells.

• The Korean Journal of Franchise Management
• /
• v.2 no.1
• /
• pp.173-199
• /
• 2011

A franchisee has to depend on the overall system, such as knowhow and management support, from a franchisor in the franchise system and the two parties do not start with the same position in economic or information power because the franchisor controls or supports through selling or management styles. For this, unfair trades the franchisor's over controlling and limiting the franchisee might occur and other side effects by the people who give the franchisee scam trades has negatively influenced on the development of franchise industry and national economy. So, the purpose of this study is preventing unfair trade for the franchisee from understanding the causes and problems of dispute between the franchisor and the franchisee focused on the dispute cases submitted the Korea Fair Trade Mediation Agency and seeking ways to secure the transparency of recruitment process and justice of franchise management process. The results of the case analysis are followed; first, affiliation contracts should run on the franchisor's exact public information statement and the surely understanding of the franchisee. Secondly, the franchisor needs to use their past experiences and investigated data for recruiting franchisees. Thirdly, in the case of making a contract with the franchisee, the franchisor has to make sure the business area by checking it with franchisee in person. Fourthly, the contracts are important in affiliation contracts, so enacting the possibility of disputes makes the disputes decreased. Fifthly, lots of investigation and interests are needed for protecting rights and interests between the franchisor and franchisee and preventing the disputes by catching the cause and more practical solutions of the disputes from the government.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.25 no.4
• /
• pp.81-96
• /
• 2020

Berthlot's reaction spectrophotometric method is generally used for the analysis of dissolved ammonium in seawater, but in recent years, a fluorescence method using an orthophthaldialdehyde-sulfite (OPA) fluorescent reagent is actively used internationally. In this study, we investigated the effects of the detection limit between the analysis methods, the reagent refractive index inherent in the spectrophotometric method, and the use of different calibration curves to understand the cause of the difference in dissolved ammonium concentration (about 0.31 𝜇M) observed in the seawater samples and a nutrient reference material between two institutions (KIOST (spectrophotometric method, one-order linear regression gradient only), Australia CSIRO (fluorescence method, quadratic formula)) conducted onboard the Australian R/V Investigator in 2017. The method detection limit (0.063 𝜇M) and the reagent refractive index background value (0.054 𝜇M) of the spectrophotometric method measured in this study could explain the difference in dissolved ammonium concentration values of the two institutes about 20% and 17%, respectively. However, when the concentration of the calibration curve of the spectrophotometric method was calculated using the same quadratic as the fluorescence method or the slope and intercept of linear regression, the difference in the dissolved ammonium concentration between the two institutions was reduced to less than the detection limit of the spectrophotometric method. Therefore, the difference in the concentration of dissolved ammonium between the two institutions, found in the nutrient reference materials and the seawater field sample during the international onboard nutrient inter-comparison experiment, may be attributed to be the effect of the different calibration curves used in the two methods rather than the effect of the difference in two analytical methods. When comparing the dissolved ammonium data from seawater samples in the future, it is recommended to pay attention to the information on the baseline, number of standard solutions, and calibration curve used in the analysis.

• Analytical Science and Technology
• /
• v.22 no.4
• /
• pp.285-292
• /
• 2009

It has been observed that, after long term storage, some ammunitions are misfired by tamping (combustionstopping) due to aging of the chemicals loaded in the ammunitions. Used in ammunitions are percussion powder which provides the initial energy, igniter which ignites the percussion powder, and a delay system that delays the combustion for a period of time. The percussion powder is loaded first, followed by the igniter and then the delay system, and the ammunitions explode by the energy being transferred in the same order. Tamping occurs by combustion-stopping of the igniter or insufficient energy transfer from the igniter to the delay system or the combustion-stopping of the delay system, which are suspected to be caused by low purity of the components, inappropriate mixing ratio, size distribution of particulate components, type of the binder, blending method, hydrolysis by the humidity penetrated during the long term storage, and chemical changes of the components by high temperature. Goal of this study is to find the causes of the combustion-stopping of the igniter and the delay system of the ammunitions after long term storage. In this study, a method was developed for testing of the combustion-stopping, and the size distributions of the particulate components were analyzed with field-flow fractionation (FFF), and then the mechanism of chemical change during long term storage was investigated by thermal analysis (differential scanning calorimetry), XRD (X-ray diffractometry), and XPS (X-ray photoelectron spectroscopy). For the ignition system, M (metal)-O (oxygen) and M-OH peaks were observed at the oxygen's 1s position in the XPS spectrum. It was also found by XRD that $Fe_3O_4$ was produced. Thus it can be concluded that the combustion-stopping is caused by reduction in energy due to oxidation of the igniter.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.4
• /
• pp.363-371
• /
• 2023

To construct a ship, blocks of various sizes must be moved and erected . In this process, lugs are used such that they match the block fastening method and various functions suitable for the characteristics of each shipyard facility. The sizes and shapes of the lugs vary depending on the weight and shape of the block structures. The structure is reinforced by welding the doubling pads to compensate for insufficient rigidity around the holes where the shackle is fastened. As for the method of designing lugs according to lifting loading conditions, a simple calculation based on the beam theory and structural analysis using numerical modeling are performed. In the case of the analytical method, a standardized evaluation method must be established because results may differ depending on the type of element and modeling method. The application of this ambiguous methodology may cause serious safety problems during the process of moving and turning-over blocks. In this study , the effects of various parameters are compared and analyzed through numerical structural analysis to determine the modeling conditions and evaluation method that can evaluate the actual structural response of the lug. The modeling technique that represents the plate part and weld bead around the lug hole provides the most realistic behavior results. The modeling results with the same conditions as those of the actual lug where only the weld bead is connected to the main body of the lug, showed a lower ulimated strength compared with the results obtained by applying the MPC load. The two-dimensional shell element is applied to reduce the modeling and analysis time, and a safety working load was verified to be predicted by reducing the thickness of the doubling pad by 85%. The results of the effects of various parameters reviewed in the study are expected to be used as good reference data for the lug design and safe working load prediction.

• 한국노년학
• /
• v.29 no.1
• /
• pp.149-175
• /
• 2009

The purpose of this research is to analyze the overall problems at the moment of October 2008, and then to find the improvements of home-help services of the Long-Term Care Insurance(LTCI), which has been revealed many problems since it was released in July 2008. The research uses the literature survey which analyzes 2nd-hand materials studied by other people already, and survey research was executed from active social workers in the area of LTCI. Based on the policy analysis framework of Gilbert and Specht, all the data are analyzed in the scopes of client·benefit(service)·finance·transferring system. This research has found the problems in each scope of home-help services of the LTCI. Firstly, the client system has some problems in mismatching between registered and service clients, estimating client number, and judging service levels. Secondly, the service system reveals deficiency in professionality of social workers, service quality lowering by loose qualification criteria on workers, non-reasonable limitation of service time available, and the same fare system applied to visiting-help service in spite of different levels. Thirdly, in financing system, clients need to pay additional money to get extra services such as meal, hair cutting, bathing etc., due to government financial support stopped, some organizations have to reduce services and replace full-time workers to part-time ones, which makes the service quality worse. Lastly, in the transferring system, the management system for service quality is not well prepared. There are too much competion because of allowing too many home-help service organizations and care worker academies. The suggestions that this research has found to improve the policy are as follows. ① It is desirable to make the registered clients the service ones as many as possible in the long term perspective. ② The LTCI organization requires more workers and higher professionality. ③ Many elderly people who are not eligible now require connection system to be more served. ④ Management system and service manual for care worker are to be developed. ⑤ Laws related to the service contents and process should be modified, the proportion of client charge needs to adjust. ⑥ Home-help service organization licensed by the LTCI needs to be financially supported publicly. ⑦ Monitoring system to home-help service organization needs to be strengthened. ⑧ Evaluation tools to home-help service organization and workers is required. ⑨ Specification to open the home-help service organization needs to be more strict.

• 재활복지
• /
• v.14 no.3
• /
• pp.225-256
• /
• 2010

This study aims to provide the basic data of the rehabilitation program for the schoolchild with intellectual disability by designing new framework of the features of postural control for the schoolchild with intellectual disability. For this, the study investigated what sensations the schoolchild are using to maintain posture by selectively or synthetically applying vision, vestibular sensation and somato-sensation, and how the coordinative sensory system of the schoolchild is responding to any sway referenced sensory stimulus. The study intended to prove the limitation of motor system in estimating the postural stability by providing the cognitive motor task, and provided the features of postural control of the schoolchild with intellectual disability by measuring the onset times and orders of muscle contraction of neuron-muscle when there is a postural control taking place due to the exterior disturbance. Furthermore, by comparatively analyzing the difference between the normal schoolchild and the intellectually disabled schoolchild, this study provided an optimal direction for treatment planning when the rehabilitation program is applied in the postural control ability training program for the schoolchild with intellectual disability. Taking gender and age into consideration, 52 schoolchild including 26 normal schoolchild and 26 intellectually disabled schoolchild were selected. To measure the features of postural control, CTSIB test, and postural control strategy test were conducted. The result of experiment is as followed. First, the schoolchild with intellectual disability showed different feature in using sensory system to control posture. The normal schoolchild tended to depend on somato-sensory or vision, and showed a stable postural control toward a sway referenced stimulus on somato-sensory system. The schoolchild with intellectual disability tended to use somato-sensory or vision, and showed a very instable postural control toward a sway referenced vision or a sway referenced stimulus on somato-sensory system. In sensory analysis, the schoolchild with intellectual disability showed lower level of proficiency in somato-sensation percentile, vision percentile and vestibular sensation percentile compare to the normal schoolchild. Second, as for the onset times and orders of muscle contraction for strategies of postural control when there is an exterior physical stimulus, the schoolchild with intellectual disability showed a relatively delayed onset time of muscle control, and it was specially greater when the perturbation is from backward. As for the onset orders of muscle contraction, it started from muscles near coax then moved to the muscles near ankle joint, and the numbers and kinds of muscles involved were greater than the normal schoolchild. The normal schoolchild showed a fast muscle contracting reaction from every direction after the perturbation stimulus, and the contraction started from the muscles near the ankle joint and expanded to the muscles near coax. From the results of the experiments, the special feature of the postural control of the schoolchild with intellectual disability is that they have a higher dependence on vision in sensory system, and there was no appropriate integration of swayed sensation observed in upper level of central nerve system. In the motor system, the onset time of muscle contraction for postural control was delayed, and it proceeded in reversed order of the normal schoolchild. Therefore, when use the clinical physical therapy to improve the postural control ability, various sensations should be provided and should train the schoolchild to efficiently use the provided sensations and use the sensory experience recorded in upper level of central nerve system to improve postural control ability. At the same time, a treatment program that can improve the processing ability of central nerve system through meaningful activities with organizing and planning adapting reaction should be provided. Also, a proprioceptive motor control training program that can induce faster muscle contraction reaction and more efficient onset orders from muscularskeletal system is need to be provided as well.