• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.35-43
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• 2023

The purpose of this study is to research digital twin policies for the use of administrative services. The study was conducted through a mobile survey of 1,000 participants, and the results are as follows. First, in order to utilize digital twin technology, it is necessary to first identify appropriate services that can be applied from the perspective of Gyeonggi Province. Efforts to identify digital twin services that are suitable for Gyeonggi Province's field work should be prioritized, and this should lead to increased efficiency in the work. Second, Gyeonggi Province's digital twin administrative services should prevent duplication with central government projects and establish a model that can be connected and utilized. It should be driven around current issues in Gyeonggi Province and the demands of citizens for administrative services. Third, to develop Gyeonggi Province's digital twin administrative services, a standard model development plan through participation in pilot projects should be considered. Gyeonggi Province should lead the project as the main agency and promote it through a collaborative project agreement. It is suggested that a support system for the overall project be established through the Gyeonggi Province Digital Twin Advisory Committee. Fourth, relevant regulations and systems for the construction, operation, and management of dedicated departments and administrative services should be established. To achieve the realization of digital twins in Gyeonggi Province, a dedicated organization that can perform various roles in project promotion and operation, as well as legal and institutional improvements, is necessary. To designate a dedicated organization, it is necessary to consider expanding and reorganizing existing departments and evaluating the operation of newly established departments. The limitation of this study is that it only surveyed participants from Gyeonggi Province, and it is recommended that future research be conducted nationwide. The expected effect of this study is that it can serve as a foundational resource for applying digital twin services to public work.

• Korean small business review
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• v.41 no.4
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• pp.1-36
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• 2019

The purpose of this study is to identify the relationships among purposes and contents of smart factory building and continuous utilization of smart factory. Specifically, this study identifies two types of purposes of smart factory building as follows: (1) improving productivity, (2) increasing flexibility. In this study, three aspects of smart factory building contents were suggested like this: (1) automation area (facility automation vs. work automation), (2) big data system focus (radical transformation vs. incremental improvement), and (3) value chain integration area (internal value chain integration vs. external value chain integration). In addition, we looked at how firm size moderates the purposes - contents - continuous utilization of smart factory relationship. A questionnaire survey was conducted on 151 manufacturing companies. More specifically, out of 151 companies, 100 are small-and-medium-sized enterprises and 51 large-sized enterprises. All questionnaires were targeted at companies with Smart Factory level above level 2. The analysis results of this study using Smart PLS statistical programs are as follows. First, the purposes of smart factory building including increasing productivity and flexibility had positive impacts on all of the contents of smart factory building. Second, all of smart factory building contents had positive impacts on the continuous use of smart factory except big data system for incremental improvement of manufacturing process. Third, the impacts of smart factory building purposes implementation on smart factory building contents varied depending on whether the purpose is productivity improvement or flexibility. Fourth, it was founded that firm size moderated the relationships of purposes - contents - continuous utilization of smart factory in such a way that large-sized firms tend to empathize the link between flexibility and smart factory building contents for continuous use of smart factory, while small-and-medium-sized-firms emphasizing the link between productivity and smart factory building contents. Most of the previous studies have focused on presenting current smart factory deployment cases. However, it is believed that this research has made a theoretical contribution in this field in that it established and verified a research model for the smart factory building strategy. Based on the findings from a working-level perspective, corporate practitioners also need to have a different approach to smart factory building, which should be emphasized depending on whether their purpose of building smart factory is to increase productivity or flexibility. In particular, since the results of this study identify the moderating effect of firm size, it is deemed necessary for firms to implement a smart factory building strategy suitable for their firm size.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.305-314
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• 2023

With the development of medical technology and radiation treatment equipment, the frequency of high-precision radiation therapy such as intensity modulation radiation therapy has increased. Image-guided radiation therapy has become essential for radiation therapy in precise and complex treatment plans. In particular, with the introduction of imaging equipment for diagnosis in a linear accelerator, CBCT scanning became possible, which made it possible to calibrate and correct the patient's posture through 3D images. Although more precise reproduction of the patient's posture has become possible, the exposure dose delivered to the patient during the image acquisition process cannot be ignored. Radiation optimization is necessary in the field of radiation therapy, and efforts to reduce exposure are necessary. However, when acquiring 3D CBCT images by changing the imaging conditions to reduce exposure, there should be no image quality or artefacts that would make it impossible to align the patient's position. In this study, Rando phantom was used to scan and evaluate images for each shooting condition. The highest SNR was obtained at 100 kV 80 mA 25 ms F1 filter 180°. As the tube voltage and tube current increased, the noise decreased, and the bowtie filter showed the optimal effect at high tube current. Based on the actual scanned images, it was confirmed that patient alignment was possible under all imaging conditions, and that image-guided radiation therapy for patient alignment was possible under the condition of 70 kV 10 mA 20 ms F0 filter 180°, which showed the lowest SNR. In this study, image evaluation was conducted according to the imaging conditions, and low tube voltage, tube current, and small rotation angle scan are expected to be effective in reducing radiation exposure. Based on this, the patient's exposure dose should be kept as low as possible during CBCT imaging.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.22-32
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• 1997

This experiment was conducted to obtain information for the cultivation of Korean valerian(Valeriana lauriei var. dasycarpa Hara) which will be useful for medicinal and aromatic resources. The effect of different temperature conditions, light intensities and soil water conditions on growth, yield and component of essential oil of V. fauriei were measured at the Dankook University, Cheonan, and a study on the shading treatment was at Umsung, Chungchongbukdo, and Jinbu, Kangwondo, in 1995. V. laudei was planted at five different temperature conditions, 10, 15, 20, 25 and 3$0^{\circ}C$, eight light intensity conditions, 1, 000, 2, 500, 5, 000, 20, 000, 30, 000, 40, 000, 50, 000 and 60, 000lux, six soil water contents, 30, 45, 55, 70, 80 and 90％ of the saturated soil, during growth stage. Shading treatment was three conditions, 0, 25 and 50％, during the daytime in field conditions. Photosynthesis had a highly significant relationship with temperature conditions in a quadratic regression model, from which the temperature for the plant growth was estimated to be 17.7$^{\circ}C$. A highly significant quadratic regression was noted between temperature and leaf width or root weight of V. fauriei. It was estimated from the regression equation that the optimum temperature for root growth was 20.3$^{\circ}C$. The content of essential oil and extract rate of root was the highest in the 15~2$0^{\circ}C$. Photosynthesis also was significantly affected by light intensity in a quadratic regression model, from which the optimum light intensity for the growth was estimated to be 40, 000lux. Root yield was more produced in Jinbu than that of in Umsung. The root yield was increased by the shading treatment in Umsung, whereas it was decreased by the shading treatment in Jinbu. The content of essential oil was not affected by the shading treatment of plants during the cultivation, while the compositions of components of essential oil were related to the growing locations. As soil water content was higher, the growth and content of root extract were increased. The optimum soil moisture for the growth of V. fauriei was 80~90％ of the saturated soil. In summary, the results indicated that the growth, yield and component of essential oil in V. fauriei were affected by environmental factors as well as soil moisture.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.903-909
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• 2023

The purpose of this study is to compare and analyze the effect of changes in the patient's central position on the exposure dose and image quality of surrounding organs during a chest lateral examination using an Auto Exposure Control(AEC). The experiment was conducted on a human body phantom. A needle was attached to the lower part of the center of the coronal plane of the phantom, and a lead ruler was attached to the lower part of the detector so that the 50 cm point was located at the lower center of the AEC ion chamber. The exposure conditions were 125 kVp, 320 mA, the distance between the source and the image receptor was 180 cm, and the exposure field size was 14 × 17 inches. Only one AEC ion chamber was used at the bottom center, and the density was set to '0' and sensitivity to 'Middle', and the central X-ray was incident vertically toward the 6th thoracic vertebra. With AEC mode applied, the 50 cm point of the needle and lead ruler were aligned and the phantom was moved 5 cm toward the stomach (F5) and 5 cm toward the back (B5), and the dose factor was analyzed by measuring ESD. The ESD of the thyroid gland according to the change in patient center position was 232.60±2.20 μGy for Center, 231.22±1.53 μGy for F5, and 184.37±1.19 μGy for B5, and the ESD of the breast was 288.54±3.03 μGy for Center, F5 was 260.97±1.93 μGy, B5 was 229.80±1.62 μGy, and the ESD of the center of the lung was 337.02±3.25 μGy for Center, F5 was 336.09±2.29 μGy, and B5 was 261.76±1.68 μGy. As a result of comparing the average values of dose factors between each group, the difference in average values was statistically significant (p<0.01), and each group appeared to be independent. As a result of the study, there was no significant difference in the dose to the thyroid, breast, and center of the lung according to the change in the patient's central position, except for the breast (10%) when the patient moved forward about 5 cm. However, movement of about 5 cm posteriorly resulted in an average dose reduction of 23.7%. Additionally, when the patient's central position was moved to the rear, image quality deteriorated.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1171-1178
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• 2023

In study, we investigated changes on growth and chlorophyll concentration on sprouted barley by fractionated X-ray irradiation (FXI). Group was divided into the control group (CG), 1-time irradiation group (30 Gy once), 2-time irradiation group (15 Gy 2 times), and 3-time irradiation group (10 Gy 3 times), and 20 grains were used per group. Experimental group (EG) was exposed by using linear accelerator (Clinac IS, VERIAN, USA), by 6 MV X-ray, SSD 100 cm, 18×10 cm², 600 MU/min. Length was measured every day until 9th day, and chlorophyl was analyzed using spectrophotometer(uv-1800, shimadzu, japan) in 9th day. Data analysis was performed the One-way ANOVA using SPSS ver 26.0(Chicago, IL, USA). In the pre-germination irradiation group (Pre-GIG), the CG had greater length than the EG on all measurement days, and as the number of FXI increased, the length became shorter. In the post-germination irradiation group (Post-GIG), the length of the CG was statistically significantly greater than that of the EG on all measurement days, and as the number of FXI increased, the length also became longer. The chlorophyll concentration was higher in the Post-GIG than in the Pre-GIG, and chlorophyll concentrations of EG was higher in the Pre-GIG than in the CG, as well as and Post-GIG. In addition, the smaller the number of FXI, the higher the chlorophyll concentration in both groups. FXI was found to affect the growth and chlorophyll concentration of sprouted barley.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.42-55
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• 2008

To evaluate the accuracy of currents measured by HF radar in the coastal sea off Keum River estuary, we compared the facing radial vectors of two HF radars, and HF radar-derived currents with in-situ measurement currents. Principal component analysis was used to extract regression line and RMS deviation in the comparison. When two facing radar's radial vectors at the mid-point of baseline are compared, RMS deviation is 4.4 cm/s in winter and 5.4 cm/s in summer. When GDOP(Geometric Dilution of Precision) effect is corrected from the RMS deviations that is analyzed from the comparison between HF radar-derived and current-metermeasured currents, the error of velocity combined by HF radar-derived current is less than 5.1 cm/s in the stations having moderate GDOP values. These two results obtained from different method suggest that the lower limit of HF radar-derived current's accuracy is 5.4 cm/s in our study area. As mentioned in previous researches, RMS deviations become large in the stations located near the islands and increase as a function of mean distance from the radar site due to decrease of signal-to-noise level and the intersect angle of radial vectors. We found that an uncertain error bound of HF radar-derived current can be produced from the separation process of RMS deviations using GDOP value if GDOP value for each component is very close and RMS deviations obtained from current component comparison are also close. When the current measured in the stations having moderate GDOP values is separated into tidal and subtidal current, characteristics of tidal current ellipses analyzed from HF radar-derived current show a good agreement with those from current-meter-measured current, and time variation of subtidal current showed a response reflecting physical process driven by wind and density field.

• Information Systems Review
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• v.21 no.4
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• pp.1-29
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• 2019

The knowledge resources take a role in promoting the sustainable growth of organization. Therefore, it is important for the members of organization to acquire knowledge consistently so that the company can continue to grow. Knowledge service is the field that provides information and infrastructure which enable the members of organization to acquire new knowledge. As we recognized the importance of knowledge services, we analyzed the level of knowledge service management and development through the impact of knowledge quality on user capabilities. First, the matrix of knowledge patterns was presented based on the type of information and the level of customer interaction. According to patterns, the knowledge service was classified into three types of information providing, information analysis, and infrastructure, and then the results of structural model analysis were presented for each type. It found that the impact of knowledge service quality on user competence was different according to the type of service. The results suggested new indicators for measuring the performance of knowledge services, and provided information for reconstructing services based on the user considering the integrated operation of knowledge service and organizational designing knowledge service.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.1-34
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• 1974

These experiments pertain to various factors influencing the quantitative characters of cocoon crops in summer and early autumn seasons. Initially, in order to establish the possible ways of the silkworm rearing more than three times a year in Korea, the author attempted to get further information about the various factors affecting the cocoon crop in every silkworm rearing season. The trials were conducted eleven times a year at four places for three years. The field trial was conducted with 19 typical sericultural farmers who had been surveyed. At the same time the author statistically analyzed the various factors in close relation to tile cocoon crop in autumn season. The effect of guidance on 40 sericultural farmers was analyzed, comparing higher level farmers with lower level farmers ; and the author surveyed 758 non-guided farmers near the guided farmers during both spring and autumn seasons. In addition, another trial on the seasonal change of leaf quality was attempted with artificial diets prepared with leaves grown in each season. It was found that related factors to cocoon crops in summer and early autumn seasons appeared to be leaf quality, and temperature for young and grown larvae. A 2$^4$ factorial experiment was designed in summer season, and another design with one more level of varied temperature or hard leaf added to a 24 factorial experiment was conducted in early autumn. The experimental results can be summarized： 1. Study on the cocoon crops in the different rearing seasons 1) It was shown that earlier brushing of silkworm generally produced the most abundant cocoon crop in spring season, and earlier or later than the conventional brushing season, especially earlier brushing was unfavorable for the abundant cocoon crop in autumn season. 2) The cocoon crop was affected by the rearing season, and decreases in order of sire with spring, autumn, late autumn, summer and early autumn seasons. 3) It was Proved that ordinary rearing and branch rearing were possibles 4 times a year ; in the 1st, 3rd, 8th, and 10th brushing season. But the 11th brushing season was more favorable for the most abundant cocoon crop of branch rearing, instead of the 10th brushing season with ordinary rearing. 2. Study on the main factors affecting the cocoon crop in autumn season 1) Accumulated pathogens were a lethal factor leading to a bad cocoon crop through neglect of disinfection of rearing room and instruments. 2) Additional factors leading to a poor cocoon crop were unfavorable for rearing temperature and humidity, dense population, poor choice of moderately ripened leaf, and poor feeding techniques. However, it seemed that there was no relationship between the cocoon crop and management of farm. 3) The percentage of cocoon shell seemed to be mostly affected by leaf quality, and secondarily affected by the accumulation of pathogens. 3. Study on the effect of guidance on rearing techniques 1) The guided farms produced an average yearly yield of 29.0kg of cocoons, which varied from 32.3kg to 25.817g of cocoon yield per box in spring versus autumn, respectively. Those figures indicated an annual average increase of 26% of cocoon yield over yields of non-guided farmers. An increase of 20% of cocoon yield in spring and 35% of cocoon yield in autumn were responsible. 2) On guided farms 77.1 and 83.7% of total cocoon yields in the spring and autumn seasons, respectively, exceeded 3rd grade. This amounted to increases of 14.1 and 11.3% in cocoon yield and quality over those of non-guided farms. 3) The average annual cocoon yield on guided farms was 28.9kg per box, based on a range of 31.2kg to 26.9kg per box in spring and autumn seasons, respectively. This represented an 8% increase in cocoon yield on farms one year after guidance, as opposed to non-guided farms. This yield increase was due to 3 and 16% cocoon yield increases in spring and autumn crops. 4) Guidance had no effect on higher level farms, but was responsible for 19% of the increases in production on lower level farms. 4. Study on the seasonal change of leaf quality 1) In tests with grown larvae, leaves of tile spring crop incorporated in artificial diets produced the best cocoon crop; followed by leaves of the late autumn, summer, autumn, and early autumn crops. 2) The cocoon crop for young larvae as well as for grown larvae varied with the season of leaf used. 5. Study on factors affecting the cocoon crops in summer and early autumn A. Early autumn season 1) Survival rate and cocoon yield were significantly decreased at high rearing temperatures for young larvae 2) Survival rate, cocoon yield, and cocoon quality were adversely affected by high rearing temperatures for grown larvae. Therefore increases of cocoon quantity and improvement of cocoon quality are dependent on maintaining optimum temperatures. 3) Decreases in individual cocoon weight and longer larval periods resulted with feeding of soft leaf and hard leaf to young larvae, but the survival rate, cocoon yield and weight of cocoon shell were not influenced. 4) Cocoon yield and cocoon quality were influenced by feeding of hard leaf to grown larvae, but survival rate was not influenced by the feeding of soft leaf and hard leaf. 5) When grown larvae were inevitably raised at varied temperatures, application of varied temperature in the raising of both young and grown larvae was desirable. Further research concerning this matter must be considered. B. Summer season 1) Cocoon yield and single cocoon weight were decreased at high temperatures for young larvae and survival rate was also affected. 2) Cocoon yield, survival rate. and cocoon quality were considerably decreased at high rearing temperatures for grown larval stages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.1-29
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• 1969

Experiments on rice concerning it s varieties, fertilization, seedling dates and herbicides have been conducted to determine the most desirable method of direct sowing cultivation on dry paddy field land in the middle part of Korea. The results obtained at the Office of Rural Development of Choongnam Province are as follows:. 1. Sixteen different derivatives from the main varieties of low land rice were cultivated on a dry paddy field by the direct sowing method; at the same time, a few varieties were tried adopting the common transplanting cultivation method. The yield and yield factors from these two groups were examined to give the following results: a) Compared to the common transplanting cultivation, the direct sowing method showed remarkably increased number of panicles while the number of flowers per panicle was shown to be significantly decreased. The maturing ratio was detected to be lowered. The yield horn them differed according to the different varieties : good yield was obtained from Hokwang while Norin ＃25 proved poor when compared with the common transplanting cultivation method. b) Among sixteen varieties tested, Sunsou, Norin ＃25, Jaigou, Hokwang, Palkueng and Gosi showed comparatively high yields, their yield being more than 325 kilograms per 10 Are, but Nampoong, Paldal, Nongkwang, Norin ＃29, Eunbangju ＃101 and Shiro gane showed less yield, their yield being less than 271 kilograms per 10 Are, the relations between the yield and the yield factors can be summarized as follows; Number of varieties and their rice yield. 1) The varieties which were great in the, number of panicles and high in yield=Jaigoun, Hokwang Palkueng and Gosi. 2) The varieties which were low in the number of panicles and high in yield=Sounsou and Norin ＃25. 3) The varieties which were great in the number of panicles and poor in yield=Eunbangju ＃101 and Sirogane. 4) The varieties which were poor in the number of panicles and poor in yield: Nampung, Paldal and Norin ＃29. Number of flowers per panicle and yield. 1) The varieties which were great in the number of flowers per panicle and high in yield: Sounsou, Norin ＃25 and Gosi. 2) The varieties which were poor in the number of flowers per panicle and high in yield ; Jaigoun, Hokwang and Palkueng. 3) The varieties which were great in the number of flowers per panicle and poor in yield: Paldal and Nampung. 4) The varieties which were poor in the number of flowers per panicle and poor in yield: Norin ＃29. Eunbangju ＃101 and Sirogane. Maturing ratio and yield. 1) The varieties which were high in the maturing ratio and high in yield: Jaigoun, Sounsou, Norin ＃25 and Palkueng. 2) The varieties which were low in the maturing ratio and high in yield: Hokwang and Gosi. 3) The varieties which were early maturing rat io and low in yield: Hokwang and Gosi. 4) The varieties which were late maturing ratio and poor in yield: Eunbangju ＃101, Nampungand Sirogane 1, 000 grain weight and yield. 1) The varieties which were heavy in 1, 000 grains weight and high in yield=Norin ＃25 and Hokwang. 2) The varieties which were light in 1, 000 grains weight and high in yield=Sounsou and Jaigoun. 3) The varieties which were heavy in 1, 000 grains weight and poor in yield=Nongkwang and Eunbanju. 4) The varieties which were light in 1, 000 grains weight and poor in yield=Norin ＃29 and Sirogane. 2. The experiment on fertilization showed that the most desirable amount to be given per 10 Are was 10 kilograms of Nitrogen, 5 kilograms of phosphate and 6 kilograms of potassium; and when the Nitrogen given exceeded 8 kilograms, its effect was better when given in amsll consecutive (split) amounts, while the maturing ratio and the number of the flowers per panicle increased when Nitrogen was given in large amount during the later stage of growth of rice. 3. The experiment on the date and amount of seedling showed that the tested variety, Sunsou gave the best results when planted on the days between 25 April and 10 May. Eight liters per 10 Are were preferable if planted early and 12 liters per 10 Are if planted late. The reason why the later planting gave a lower yield was that the number of flowers per panicle was fewer. 4. The experiment on the irrigation for rice with direct sowing cultivation immersed in water showed that it was the most satisfactory when irrigated on 25th June, 55 days after its seedling, its plot giving the best yield. The plots 10th June and 15th July showed just as good results. However, irrigated later, than 15th July it showed lower yields. 5. Compared to the yield of the plot controlled by the common method, the yield from the plots treated with chemical herbicide such as LOROX, TOK, PCP, SWEP, Mo-338 on dry condition soil seemed poorer, but significant difference was not found statistically. On the other hand in the case where chemical herbicides such as TOK, Mo-338, Stam F-34 or ORDRAM were used after irrigation, the yield from the ORDRAM and TOK treated plots did not show significant differences compared to the common hand weed controling method, but those treated with chemicals other than the above showed a lower yield.