• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.1-8
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• 2008

The objectives of this study were to compare nutrient natural input between thinned and unthinned natural hardwood stands at Mt. Joongwang, Pyongchang-gun, Gangwon-do. Throughfall, stemflow, A-layer and B-layer soil water as well as litterfall were sampled at two-week intervals during the period of June to October from 2002 to 2004. The amount of rainfall interception in thinned and unthinned natural hardwood stands was as 12% and 18%, respectively. The results indicated that there was no difference in annual nutrient input by rainfall between thinned and unthinned stands. $Na^+$, $Cl^-$ and $SO_4{^{2-}}$ concentrations of A-layer soil water in the unthinned stand were higher than those in the thinned stand. In the B-layer soil water, $Ca^{2+}$, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$ concentrations in the unthinned stand were higher than those in thinned stand. Mean annual litterfall input was $2,706kg\;ha^{-1}$ in unthinned stand and $2,589kg\;ha^{-1}$ in thinned stand. Total-N input from litterfall was $50.28kg\;ha^{-1}yr^{-1}$ in the unthinned stand and $36.81kg\;ha^{-1}yr^{-1}$ in the thinned stand, while there was no difference in exchangeable cation input from litterfall between thinned and unthinned stands. Thus, the difference in nutrient inputs except for N by throughfall, stemflow and litterfall between the two stands was not influenced by thinning.

• Journal of Biosystems Engineering
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• v.1 no.1
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• pp.1-6
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• 1976

This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

• Progress in Medical Physics
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• v.17 no.1
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• pp.24-31
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• 2006

Automated analysis software was developed to measure the magnitude of the intrafractional and interfractional errors during breast radiation treatments. Error analysis results are important for determining suitable planning target volumes (PTV) prior to Implementing breast-conserving 3-D conformal radiation treatment (CRT). The electrical portal imaging device (EPID) used for this study was a Portal Vision LC250 liquid-filled ionization detector (fast frame-averaging mode, 1.4 frames per second, 256X256 pixels). Twelve patients were imaged for a minimum of 7 treatment days. During each treatment day, an average of 8 to 9 images per field were acquired (dose rate of 400 MU/minute). We developed automated image analysis software to quantitatively analyze 2,931 images (encompassing 720 measurements). Standard deviations ($\sigma$) of intrafractional (breathing motion) and intefractional (setup uncertainty) errors were calculated. The PTV margin to include the clinical target volume (CTV) with 95% confidence level was calculated as $2\;(1.96\;{\sigma})$. To compensate for intra-fractional error (mainly due to breathing motion) the required PTV margin ranged from 2 mm to 4 mm. However, PTV margins compensating for intefractional error ranged from 7 mm to 31 mm. The total average error observed for 12 patients was 17 mm. The intefractional setup error ranged from 2 to 15 times larger than intrafractional errors associated with breathing motion. Prior to 3-D conformal radiation treatment or IMRT breast treatment, the magnitude of setup errors must be measured and properly incorporated into the PTV. To reduce large PTVs for breast IMRT or 3-D CRT, an image-guided system would be extremely valuable, if not required. EPID systems should incorporate automated analysis software as described in this report to process and take advantage of the large numbers of EPID images available for error analysis which will help Individual clinics arrive at an appropriate PTV for their practice. Such systems can also provide valuable patient monitoring information with minimal effort.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.101-110
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• 2014

This study analyzes the validity of the type classification of the type and design changes of apartment landscaping planting construction design changes that were completed in the private sector, efficiently manages the design changes that are displayed over landscaping planting work in general in the future, and performs research by placing the object underlying the presentation. The results are as follows. First, the percentage that occurred in the planting construction of design changes that have occurred in the apartment landscaping construction was carried out in the private sector and accounted for 61.8%. This indicates that part of the planting is a major design change. Second, as the cause of such a design change to be those associated with the field conditions such as lack of main construction period. In particular, due to a change in oral, appeared 7-48 times design changes of one review design change approval is complex, design changes of planting construction had shown a feature that occurs in multiple simultaneous. Third, the 7 types of Design Changes in planting design were delineated as 'design changes for consideration of the user', 'design changes for image improvement', 'design changes for ease of maintenance', 'design changes due to the mismatch of design statement', 'design changes due to the relationship with the engineering species of other', 'design changes due to lack of field study', and 'design changes due to the consideration of feasibility.' Fourth, 'design changes for consideration of the user' and 'design changes for image improvement' were found in more than half of the frequency of the overall changes. This differed from the results shown in public corporations. Fifth, if planting construction design change process, private companies, it was found that is showing the approval of the practice after the previous construction of the construction cost savings due to construction time. However, in the case of a public corporation, these exhibited a different aspect from the private sector and show a design change procedure that reflects the changes after the design change events in the field have occurred. The above results, the type of landscaping works in planting design change of public enterprises, regardless of the private sector, is the same in the seven types, the main reason of and procedures for design changes, indicating that there are other respects. In design change, it may be desirable to apply becomes liquidity rationality and efficiency of the dimension, depending on the nature of the landscape construction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.855-858
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• 2006

First of all, Developing information technology makes it possible to change a paradigm of all kinds of areas, including an education. Students can choose learning goals and objects themselves and acquire not the accumulation of knowledge but the method of their learning. Moreover, Teachers get to be adviser, and students play a key role in teaming. That is, the subject of leaning is students. Constructivism emphasizes the student-oriented environment of education, which corresponds to the characteristics of hypeimedia. In addition, Internet allows us to make a practical plan for constructivism. Web Based Internet provides us with a proper environment to make constructivism practice md causes an education system to change. Sure Web Based Instruction makes them motivated to learn more, they can gain plenty of information regardless of places or time. Besides, they are able to consult more up-to-date information regarding their learning use hypermedia such as an image, audio, video, and test, and effectively communicate with their instructor through a board, an e-mail, a chatting etc. A school and instructors have been making effort to develop a new model of a teaching method to cope with a new environment change. In this thesis, with 'Design and Implementation of Web Based Instruction Based on Constructivism', providing online learner-oriented and indexed video lesson, learners can get chance of self-oriented learning. In addition, learners doesn't have to cover all contents of a lesson but can choose contents they want to have from a indexed list of a lesson, and they ran search contents they want to have with a 'Keyword Search' on a main page, which can make learners improve learner's achievement.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.217-220
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• 2004

According as utilization for web increases rapidly, it is demanded that model about support interaction between web-based applications systematically and solutions can integrate new distributed platforms and existing environment effectively, accordingly, Web Services appeared by solution in reply. These days, a lot of software and hardware companies try to adoption of Web Services to their market, attenpt to construct their applications associationing components from various Web Services providers. However, to execute Web Services completely. it must have interoperability and need the standardization work that avoid thing which is subject to platform, application as well as service and programming language from other companies. WS-I (Web Services Interoperability organization) have established Basic Profile 1.0 based on XML, UDDI, WSDL and SOAP for web services interoperability and developed usage scenario Profile to apply Web Services in practice. In this paper, to verify suitability Web Services interoperability between heterogeneous two applications, have design and implements the Book Information Web Services that based on the Web Services Client of J2SE platform and the Web Services Server of .NET platform, so that analysis and verify the service by adaptation of WS-I Basic Profile.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.633-638
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• 2017

The amount of radioactive waste has been rapidly increased with development of radiation treatment in medical field. Recently, it has been a common practice to use I-131 for thyroid cancer, F-18 for PET/CT and Tc-99m for diagnosis of nuclear medicine. All the wastes concerned have been disposed of by means of the self-disposal method, for example incineration, after storage enough to decay less than clearance level. IAEA proposed criteria for clearance level of waste which depends on the individual ($10{\mu}Sv/y$) and collective dose (1 man-Sv/y), and concentration of each nuclide (IAEA Safety Series No 111-P-1.1, 1992 and IAEA RS-G-1.7, 2004). In this study, specific radioactivity of radioactive waste contaminated with Re-186 was measured to confirm whether it meets the clearance level. Re-186 has long half life of 3.8 days relatively and emits beta and gamma radiation, therefore it can be applied in treatment and imaging purposes. The specific radioactivity of contaminated gloves weared by radiation workers was measured by MCA(Multi-channel Analyzer) which was calibrated by reference materials in accordance with the measuring procedure. As a result, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and physical half-life was considered, and it is showed that the physical half-life is longer than induced half-life. Therefore, the storage period of radioactive waste for self-disposal may be curtailed in case of application of induced half-life. The result of this study will be proposed as ISO standard.

• Journal of radiological science and technology
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• v.44 no.5
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• pp.525-534
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• 2021

In order to provide high-quality medical services to the public and contribute to the improvement of public health, it is necessary to enact an independent law according to the work of radiological technologists. Therefore, this study intends to review the regulations related to radiographers in the Medical Service Technologists, etc. Act. and to present opinions and directions for enactment of individual laws for radiological technologists. An online survey was conducted to 15,000 radiological technologists working in medical institutions and education sites in Korea; 1,027 people (6.85%) responded. The questionnaire consisted of 3 questions on demographic characteristics, 5 questions on the scope of work, and 12 questions on the revision of the Medical Service Technologists, etc. Act. and the establishment of the Radiological Technologist Independent Act. Reliability and factor analysis were performed on 9 questions measured on a Likert 5-point scale in "Revision of the Medical Service Technologists, etc. Act. and the establishment of the Radiological echnologist Independent Act" among the questionnaire items. Reliability for the total 9 questions was Chronbach α=0.728. There was a high perception that the regulations related to radiological technologists were insufficient in the current Medical Service Technologists, etc. Act., and the perception that examinations performed by radiological technologists at medical institutions were included in medical practice was high. If the Radiological Technologist Independent Act is enforced, a high percentage of respondents said that they could receive legal protection through the institutionalization of the scope of work, that the status of radiological technologists would be improved, and the scope of work would be expanded. The response that the scope of work of radiological technologists should be included was the highest at 96.6%. In the analysis according to demographic characteristics, it was found that 96.7% of the respondents were agreed regardless of the factors. Radiological technologists will have to work hard to secure the public health by coping with new radiology devices, procedures and treatment methods. Therefore, as the results of this study, it is expected that the enactment and implementation of the Radiological Technologist Independent Act will contribute to the improvement of the quality of treatment for patients and to the public health.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.695-703
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• 2018

This study was conducted to suggest a sustainable farming practice forresource recycling in vegetable gardens of North Korea. In North Korea, farmers are allowed to own private vegetable gardens less than $100m^2$. However, usage of fertilizers in private vegetable gardens is very limited due to economic sanctions by UN security council. If North and South Korea initiated the cooperative action in the near future, agricultural sector would be the highest priority cooperation area. Considering the current North Korean situation in agriculture, we would like to suggest a method for producing organic fertilizer manure. For raw materials for producing manure, we selected corn byproduct, which is the most abundant material, and rabbits' feces, which are easily obtained from individual private farms in North Korea. As we cannot get corn byproducts and rabbits' feces from North Korea, we prepared samples of corn byproducts and rabbits; feces from many places in South Korea. After statistical analysis of variance, there was no significant difference in the T-N contents of corn byproducts from Gyeonggi, Gangwon, Chungnam, Chungbuk, Jeollabuk and Gyeongsangnam-dos, which indicates that the fertilizing quality of corn byproducts does not vary significantly in the spatial scale of South. Korea. In this sense, if we use corn samples from Gyeonggi province, they would not be very different from those of North Korean regions. Physicochemical properties of rabbits' feces were different between those eating feed grains and those eating plants only. Hence, we used rabbits' feces of the rabbits from Yeonchun area, which were fed by plants only. Using three different mixing ratios of corn byproducts and rabbits' feces, composting was conducted for 60 days. The mixing ratio of 1:1 produced the manure with % T-N of 1.98% and OM/N ratio of 31.7 after 30 days of composting, which is comparable to the quality of commercial manure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.727-736
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• 2021

Road tunnel lengths are increasing. Some 1,300 tunnels with 1,102 km in length had been increased till 2019 from 2010. There are 64 tunnels over 3,000 m in length, with their total length adding up to 276.7 km. Safety facilities in the event of a tunnel fire are critical so as to prevent large-scale casualties. Standards for installing disaster prevention facilities are being proposed based on the guidelines of the Ministry of Land, Infrastructure and Transport, but they may be limited to deep underground tunnels. This study was undertaken to provide guidelines for the spacing of evacuation connection passages and the widths of evacuation connection doors. Evacuation with various spacing and widths was simulated in regards to evacuation time, which is the measure of safety, using the evacuation analysis simulation software EXODUS Ver.6.3 and the fire/smoke analysis software SMARTFIRE Ver.4.1. Evacuation connection gates with widths of 0.9 m and 1.2 m, and spacings of 150 m to 250 m, were set to every 20 m. In addition, longitudinal slopes of 6 % and 0 % were considered. It was determined to be safe when the evacuation completion time was shorter than the delay diffusion time. According to the simulation results, all occupants could complete evacuation before smoke spread regardless of the width of the evacuation connection door when the longitudinal slope was 6 % and the interval of evacuation connection passage was 150 m. When the evacuation connection passage spacing was 200 m and the evacuation connection gate width was 1.2 m, all occupants could evacuate when the longitudinal slope was 0 %. Due to difference in evacuation speed according to the longitudinal slope, the evacuation time with a 6 % slope was 114 seconds shorter (with the 190 m connection passage) than with a 0 % slope. A shorter spacing of evacuation connection passages may reduce the evacuation time, but this is difficult to implement in practice because of economic and structural limitations. If the width of the evacuation junction is 1.2 m, occupants could evacuate faster than with a 0.9 m width. When the width of a connection door is 1.2 m with appropriate connection passage spacing, it might provide a means to increase economic efficiency and resolve structural limitations while securing evacuation safety.