• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.217-228
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• 1999

The three methods of analysis (i) REV(representative elemental volume), (ii) non-REV and (iii) joint network analysis are introduced in this paper to analyze the groundwater flow in jointed rock mass and the inflow into underground excavations. The results from those methods are compared one another to reveal their characteristics by varying the number of joints and the diameter of the opening. The pre-processor, the so-called sequential analysis, is introduced to predict the equivalent hydraulic conductivity of a jointed rock mass having a number of intersecting joints. Using the finite element mesh, joint map and sequential analysis, the equivalent hydraulic conductivities are calculated for all 445 elements. The hydraulic inhomogeneity and the determination of the representative properties of jointed rock masses are discussed. In the REV analysis where the entire rock mass is homogenized through the representative properties, the inflow is increased regularly and consistently by increasing the joint density, the opening size and the conductivity contrast value. Though the non-REV analysis showed irregular variation of the inflow due to the local inhomogeneity allowed to individual elements, the inflow approached the REV results as the characteristic length increases. The joint network analysis showed the most sensitive reaction to the joint density, the opening size and the presence of the network crossing the opening. The reliability of the network analysis depends on the geometric data of individual joints. In view of the limited field data on joint geometry and possible uncertainty the REV and non-REV methods are considered more practical and rational than the joint network analysis.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.2
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• pp.235-251
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• 2005

German working hour law of 1994(Arbeitszeitgesetz) provides maximum working hour as 8 hours a day and 48 hours per week. The law provides that minimum 11 hours rest-time is required between the end of a day's work and the beginning of the next day's work. Namely, the hour that the workers are put under commanding of the user is restricted within 13 hours per day. In the meantime, article 5, 7, 14, and 15 of the law have some letting the exceptional provisions regarding the working hour and rest-time of flight crew, and 2nd administrative order for the aviation transportation business owner, which is established based on such exceptional provisions(2.DV LuftBO), provides the working hour and rest-time of flight crew quite in detail. The administrative order is detailed quite regarding block time, flight working hour, and rest-time. So, it does not need to interpret additionally. Airlines in Korea should observe the both Labor Standard Act applying to general workers and Aviation Act focused on flight crew, so it is difficult that airlines manages working hour and rest-time of the flight crew efficiently. Therefore, it is desirable that our country refers to and considers adopting this legislation method of Germany which regulates working hour and rest-time of flight crew in detail in the 2.DV LuftBO.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.1
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• pp.203-319
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• 2020

The regulation of satellite remote sensing is generally included with the scope of statutes governing outer space activities. But not all states opted for dedicated satellite remote sensing regulation. The decision whether to do so depends in part on the specific capabilities of national satellite remote sensing programs. Five states that have dedicated statutes governing operations with remote sensing data are the United States, with its developed Landsat regime (the Land Remote Sensing Policy Act of 1992, LRSPA), Canada, with its Remote Sensing Systems Act, Germany, with its Satellite Data Securities Protection Act (SatDSiG), France, with its Law on Space Operations (LOS), Japan, with its Act on Ensuring Appropriate Handling of Satellite Remote Sensing Data. The major purpose of this article is to shed light on some legal issues surrounding remote sensing activities by comparative review. The paper analyzes international conventions or soft law and national law and policies relating to satellite remote sensing. It also offers some implications and suggestions for regulations of satellite remote sensing operations and satellite data.

• Analytical Science and Technology
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• v.29 no.6
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• pp.261-268
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• 2016

TXRF is a powerful technique for the soil sample analysis due to its ability to conduct quantitative analysis of powder sample without complicated pre-treatment processes. The conventional internal standard method used for this technique suffers from relatively low accuracy because of varying matrix effects of soil. In order to improve the accuracy, external standard method was applied to analyze two types of soil samples; acid-dissolutionized soil solution and detergent-suspended soil powder. Individual ICP-AES/MS grade standards were mixed, diluted and measured to create standard curves, but applying these curves for analyzing the soil solution sample did not make any improvement in comparison with the internal standard method. On the other hand, standard curves were created with using standard soil powders for the analysis of soil powder samples, and we found that this method increased the accuracy significantly relative to the internal standard method. Especially, Al, Fe, K, Ca, Ti, Ba, Mn, Sr, Rb, Cu was measured with relatively high accuracy (relative error = ${\pm}20%$).

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.339-346
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• 2018

Cyanazine is a member of the triazine family of herbicides. Cyanazine is used as a pre- and post-emergence herbicide for the control of annual grasses and broadleaf weeds. This experiment was conducted to establish a determination method for cyanazine, as domestic unregistered pesticide, residue in major agricultural commodities using HPLC-DAD/MS. Cyanazine was extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice and soybean. The extract was diluted with saline water and partitioned to dichloromethane for remove polar extractive in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized florisil column chromatography. On a $C_{18}$ column in HPLC, cyanazine was successfully separated from co-extractives of sample, and sensitively quantitated by diode array detection at 220 nm. Accuracy and precision of the proposed method was validated by the recovery experiment on every major agricultural commodity samples fortified with cyanazine at 3 concentration levels per agricultural commodity in each triplication. Mean recoveries were ranged from 83.6 to 93.3% in five major representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation(LOQ) of cyanazine was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring(SIM) technique was also provided to clearly identify the suspected residue.

• Radiation Oncology Journal
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• v.18 no.3
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• pp.194-199
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• 2000

Purpose : Then determining the lower margin of post-operative pelvic radiation therapy field according to the traditional method (recommended by Gunderson), the organs located in the low pelvic cavity and the perineum are vulnerable to unnecessary radiation. This study evaluated the effect of individualized determination of the lower margin at 2 cm to 3 cm below the anastomotic site on the failure patterns. Materials and Methods . Authors included ぉ patients with modified Astler-Coiler (MAC) stages from B2 through C3, who received low anterior resection and post-operative pelvic radiation therapy from Sept. 1994 to May 1998 at Samsung Medical Center, Sungkyunkwan University. The numbers of male and female patients were 44 and 44, and the median age was 57 years (range: 32-81 years). Three field technique (posterior-anterior and bilateral portals) by 6, 10, 15 MV X-rays was used to deliver 4,500 cGy to the whole pelvis followed by Sn cGy's small field boost to the tumor bed over 5.5 weeks. Sixteen patients received radiation therapy by traditional field margin determination, and the lower margin was set either at the low margin of the obturator foramen or at 2 cm to 3 cm below the anastomotic site, whichever is lower. In 72 patients, the lower margin was set at 2 cm to 3 cm below the anastomotic site, irrespectively of the obturator foramen, by which the reduction of radiation volume was possible in 55 patients ($76\%$). Authors evaluated and compared survival, local control, and disease-free survival rates of these two groups. Results : The median follow-up period was 27 months (range : 7-58 months). MAC stages B2 in 32($36\%$), B3 in 2 ($2\%$), Cl in 2 ($2\%$), C2 in 50 ($57\%$), and C3 in 2 ($2\%$) Patients, respectively. The entire patients' overall survival rates at 2 and 4 years were $94\%$ and $68\%$, respectively, and disease-free survival rates at 2 and 4 years were $86\%$ and $58\%$, respectively. The first failure sites were local only in 4, distant only in 14, and combined local and distant in 1 patient, respectively. There was no significant difference with respect to local control and disease-free survival rates ( p=0.42, p=0.68) between two groups of different lower margin determination policies. Conclusion : The new concept in the individualized determination of the lower margin depending on the anastomotic site has led to the equivalent local control and disease-free survival rates, and is expected to contribute to the reduction of unnecessary radiation-related morbidity by reduction of radiation volume, compared with the traditional method of lower margin determination.

• The Korean Journal of Air & Space Law and Policy
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• v.34 no.1
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• pp.235-268
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• 2019

Under the Aviation Safety Act of Korea, any person who intends to operate a drone is required to follow the operational conditions listed below, unless approved by the Minister of Land, Infrastructure, Transport and Tourism; (i) Operation of drones in the daytime, (ii) Operation of drones within Visual Line of Sight, (iii) Maintenance of a certain operating distance between drones and persons or properties on the ground/ water surface, (iv) Do not operate drones over event sites where many people gather, (v) Do not transport hazardous materials such as explosives by drone, (vi) Do not drop any objects from drones. Requirements stated in "Airspace in which Flights are Prohibited" and "Operational Limitations" are not applied to flights for search and rescue operations by public organizations in case of accidents and disasters. This paper analyzes legal issues as to definition and regulations of drones in Korean Aviation Safety Act. This paper, also, offers some implications and suggestions for regulations of drones under Korean Aviation Safety Act by comparing the regulations of drones in Japanese Civil Aeronautics Act.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1737-1741
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• 2014

An HPLC method for determination of naringin was developed to standardize it as a marker compound in Goheung yuzu extract as a functional health food. Optimum results were obtained by C-18 column chromatography using solvent mixtures (A: 0.5% acetic acid, B: acetonitrile) as the stationary phase and mobile phase. The method was fully validated and sensitive with a limit of detection (LOD) of 0.0218 mg/L and limit of quantification (LOQ) of 0.0661 mg/L. The method showed high linearity (coefficient of correlation=0.9986) and high accuracy, as recovery rates of naringin at concentrations of 1, 0.5, 0.1, 0.05 mg/mL were in the ranges of 95.74~98.25%, 97.67~101.01%, 97.33~104.64%, and 95.53~106.82%, respectively. Intra-day and inter-day variation, which are measures of method precision, were 1.39~1.95% and 0.17~1.49%, respectively. Therefore, the method could be used without modification for determination of naringin as a marker compound in Goheung yuzu extracts.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.44-49
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• 2018

As generic health functional food items have been expanded, this research project has been conducted to prepare a scientific and systematic standardized analytical method of relevant food item and examine the suitability of the method for health/functional foods on sale. Total polyphenol was necessary for development and verification of standardized analytical method. The method exhibited high linearity in the tannic acid calibration curve ($r^2$ > 0.999) over concentrations of $5-50{\mu}g/mL$. The limits of detection and quantitation for tannic acid were $5{\mu}g/mL$ and $15{\mu}g/mL$, respectively, while tannic acid recovery was 102.3-112.4% with standard deviations of 0.8-3.2%. To verify the accuracy of the analytical method, the labeled amounts of purchased health functional foods were monitored. The recovery for tannic acid was 105.6% of the labeled amounts. Thus, the new method was suitable for all cases.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.657-664
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• 2003

Reliable tracking of moving humans is essential to motion estimation, video surveillance and human-computer interface. This paper presents a new approach to human motion tracking that combines appearance-based and model-based techniques. Monocular color video is processed at both pixel level and object level. At the pixel level, a Gaussian mixture model is used to train and classily individual pixel colors. At the object level, a 3D human body model projected on a 2D image plane is used to fit the image data. Our method does not use inverse kinematics due to the singularity problem. While many others use stochastic sampling for model-based motion tracking, our method is purely dependent on nonlinear programming. We convert the human motion tracking problem into a nonlinear programming problem. A cost function for parameter optimization is used to estimate the degree of the overlapping between the foreground input image silhouette and a projected 3D model body silhouette. The overlapping is computed using computational geometry by converting a set of pixels from the image domain to a polygon in the real projection plane domain. Our method is used to recognize various human motions. Motion tracking results from video sequences are very encouraging.