• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.452-458
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• 2020

In this study we aimed to find out pesticide types with probability for underestimation of dietary exposure to pesticide residues in Korea by comparing the residue definitions between Korea and Codex standards. In addition, we sought to establish priorities regarding the necessity of review concerning pesticide types and their impacts based on the risk assessment and dietary exposure underestimation. As a result, we found that according to the residue definition information, 44 pesticides have probability for underestimation in terms of dietary exposure assessments. Among them, 24 pesticides have priority for review of dietary exposure underestimation and its impacts on risk assessment, based on the ADI values of pesticides, Korean MRL information and toxicological information of metabolite. The 24 pesticides were as follows: acibensolar-S-methyl, chlorfenapyr, chlorothalonil, cyantraniliprole, cyclaniliprole, cyflumetofen, dithiocarbamates, fenamidone, fenpyroximate, fluazifop-P-butyl, fluopicolide, flupyradifuron, fluxapyroxad, glyphosate, hexythiazox, isoprothiolane, isopyrazam, myclobutanil, penthiopyrad, propiconazole, spinetoram, spiromesifen, spirotetramat, trifloxystrobin. Furthermore, chlorfenapyr, chlorothalonil, dithiocarbamates and fenamidone may have considered a top priority for review due to greater toxicity of metabolite. This study could be of great use for improvement on risk assessment approaches in South Korea regarding pesticide residues in food commodities.

• Korean Journal of Community Nutrition
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• v.17 no.4
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• pp.365-375
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• 2012

The purpose of this study was to develop a risk communication material on artificial food color additives for elementary school students. The development was based on a previous study on the perception and information needs of elementary school students on artificial food colors including that the students usually were interested in artificial food colors, but didn't know about those well, and they wanted to get information on the safety of their intake, function and necessity of food color additives. Based on the above results, a comic book on artificial food colors was developed as a risk communication material for the elementary school students by brainstorming and consultation with experts. The book was titled as 'Variegated artificial food colors! Understanding and Eating'. It contained basic information on food additives focused on artificial food colors including definition, function, calculation of ADI, usage of artificial food colors, quizzes and useful web sites, etc. The results of field evaluation for the developed material by 101 elementary school students were very positive in getting the correct information, understanding artificial food colors and having proper attitude for healthy dietary life. Therefore, the developed material could be used to help elementary school students have proper perception on artificial food colors and facilitate the risk communication on food additives.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1306-1315
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• 2017

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane) is one of the organic synthetic pesticides that has many negative effects for human health and the environment. The purpose of this study was to investigate the synergistic effect of mixed cutures of white-rot fungus, Pleurotus ostreatus, and biosurfactant-producing bacteria, Pseudomonas aeruginosa and Bacillus subtilis, on DDT biodegradation. Bacteria were added into the P. ostreatus culture (mycelial wet weight on average by 8.53 g) in concentrations of 1, 3, 5, and 10 ml ($1ml{\approx}1.25{\times}10^9$ bacteria cells/ml culture). DDT was degraded to approximately 19% by P. ostreatus during the 7-day incubation period. The principal result of this study was that the addition of 3 ml of P. aeruginosa into P. ostreatus culture gave the highest DDT degradation rate (approximately 86%) during the 7-day incubation period. This mixed culture combination of the fungus and bacteria also gave the best ratio of optimization of 1.91. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl) ethane), DDE (1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene), and DDMU (1-chloro-2,2-bis(4-chlorophenyl) ethylene) were detected as metabolic products from the DDT degradation by P. ostreatus and P. aeruginosa. The results of this study indicate that P. aeruginosa has a synergistic relationship with P. ostreatus and can be used to optimize the degradation of DDT by P. ostreatus.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.303-312
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• 1998

It is necessary to quantitatively asses the influence of tidal currents to analysis the coastal current patterns before or after constructing offshore structures like as breakwaters. This assesment can be made through the use of simulation models designed to reproduce the water movements of the area. And it is very important to predict a phenomenon of pollutant dispersion in the area. In this study, in order to predict the changes of sea water quality for the port development plan, Ilgwang harbour, located at the east coast of Pusan, the numerical computations were carried out. The flow patterns were investigated before and after the development of the harbour bay and coastal area connected on it. The computational models are an extension of earlier work on the flow which used the ADI Method (Alternating Direction Implicit Method) in appling to Osaka Bay by KANEKO et al. The transport of pollutant constituents depends upon the currental characteristics of the water-transporting medium. In the currental flow model, water velocities and water levels are computed throughout the regions of it. These value are then used in the mass-balance equation to obtain the pollutant-constituent transport. As a result of this research, the present water quality of Ilgwang harbour and the coastal areas connected on it was proved out some good condition. The changes of sea water quality due to the port development plan of the Ilgwang habour bay and the coastal area were not large compared with the present condition, but it will be likely able to get worse by increasing the semi-enclosed areas in the harbour bay. In order to improve the water quality of the area after development, the method to activate tidal exchange in the area can be needed, as a mitigation technique.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.603-603
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• 2015

모든 외재적 형식의 가뭄을 모니터링하고 예측 및 평가하기 위해서는 가뭄지수가 필수적 요소로써 이용된다. 일반적으로 가뭄지수는 단일지수(single index), 다중지수(multiple index), 복합지수(composite index)로 분류되며 대부분 강수량, 유출량, 토양 수분량 등과 같은 하나의 변수만을 사용하는 단일지수이다. 가뭄지수는 가뭄평가에 있어서 각각의 장단점이 있다. 하나의 변수를 사용하는 가뭄지수는 계산이 간편하지만 가뭄의 물리적 특성을 정확하게 반영할 수 없기 때문에 신뢰할 수 있는 가뭄평가에 충분하지 않다. CDI(Composite Drought Index)는 PDSI(Palmer Drought Index), ADI(Aggregate Drought Index), SWSI(Surface Water Supply Index)와 같은 다중지수의 개념을 착안하여 고안되었으며, 모든 가뭄 형태(농업적 수문학적 기상학적)와 관련된 강우량, 유출량, 정규식생지수(NDVI)를 변수로써 사용하였다. NDVI는 MODIS(Moderate resolution imaging spectroradiometer)에서 제공하는 16일 간격의 위성자료를 이용하여 계산되었고 이와 시간 스케일을 맞추기 위해 나머지 두 변수 또한 16일 시계열을 사용하였다. CDI는 (1)각 변수들의 시계열을 행렬로 나타내고 (2)이것을 정규화하여 무차원 행렬로 변환한 후 (3)연구 지역의 최고습윤상태(most wet condition) 및 최고건조상태(most dry condition)의 차이값을 기반으로 하여 산정된다. 본 연구에서는 상대적으로 다른 유역에 비해 장기적이고 연속적인 자료를 확보할 수 있으며 농경지와 산림지역 비율이 높은 낙동강 유역을 대상유역으로 설정하였으며, 2001-2013년 기간의 자료를 이용하였다. 그 결과 연구 기간 중 실제 발생했던 가뭄을 반영하는 것을 확인하였다. 또한 CDI는 다양한 변수의 활용으로 가뭄의 물리적 특성의 반영이 가능하며 연구 지역의 기상 조건에 직접적으로 관련된 결과를 나타낸다. 자료의 가용성에 따라 적용범위가 제한적일 수 있으나 입력값으로 사용된 변수와 시계열을 편의와 효율에 따라 유연하게 적용할 수 있다. 따라서 CDI는 농업적, 수문학적, 기상학적 가뭄의 모든 관점을 통합하는 실용적 가뭄지수로써 사용될 수 있는 가능성을 포함하고 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.148-148
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• 2018

Land subsidence caused by excessive groundwater pumping is a serious hydro-geological hazard. The spatial variability in land use, unbalanced groundwater extraction and aquifer characteristics are the key factors which make the problem more difficult to monitor using conventional methods. This study uses the European Space Agency (ESA) Sentinel satellites to investigate and monitor land subsidence varying with different land covers and groundwater use in the arid Quetta valley, Pakistan. The Persistent Scattering Differential Interferometry of Synthetic Aperture Radar (PS-DInSAR) method was used to develop 28 subsidence interferograms of the study area for the period between 16 Oct 2014 and 06 Oct 2016 using ESA's Sentinel-1 SAR data. The uncertainty of DInSAR result is first minimized by removing the dynamic effect caused by atmospheric factors and then filtered using the radar Amplitude Dispersion Index (ADI) to select only the stable pixels. Finally the subsidence maps were generated by spatially interpolating the land subsidence at the stable pixels, the comparison of DInSAR subsidence with GPS readings showed an R 2 of 0.94 and mean absolute error of $5.7{\pm}4.1mm$. The subsidence maps were also analysed for the effect of aquifer type and 4 land covers which were derived from Sentienl-2 multispectral images. The analysis show that during the two year period, the study area experienced highly non-linear land subsidence ranging from 10 to 280 mm. The subsidence at different land covers was significantly different from each other except between the urban and barren land. The barren land and seasonally cultivated area show minor to moderate subsidence while the orchard and urban area with high groundwater extraction rate showed excessive amount of land subsidence. Moreover, the land subsidence and groundwater drawdown was found to be linearly proportional to each other.

• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.139-147
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• 2019

A false alarm, which is an incorrect report of an emergency, could trigger an unnecessary action. The predictive maintenance framework developed in our previous work has a feature whereby a machine alarm is triggered based on sensor data evaluation. The sensor data evaluator performs three essential evaluation steps. First, it evaluates each sensor data value based on its threshold (lower and upper bound) and labels the data value as "alarm" when the threshold is exceeded. Second, it calculates the duration of the occurrence of the alarm. Finally, in the third step, a domain expert is required to assess the results from the previous two steps and to determine, thereby, whether the alarm is true or false. There are drawbacks of the current evaluation method. It suffers from a high false-alarm ratio, and moreover, given the vast amount of sensor data to be assessed by the domain expert, the process of evaluation is prolonged and inefficient. In this paper, we propose a method for automatic false-alarm labeling that mimics how the domain expert determines false alarms. The domain expert determines false alarms by evaluating two critical factors, specifically the duration of alarm occurrence and identification of anomalies before or while the alarm occurs. In our proposed method, Hierarchical Temporal Memory (HTM) is utilized to detect anomalies. It is an unsupervised approach that is suitable to our main data characteristic, which is the lack of an example of the normal form of sensor data. The result shows that the technique is effective for automatic labeling of false alarms in sensor data.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.348-353
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• 2019

This study was conducted to monitor the carbendazim residues in soybean and mungbean sprouts using LC-MS/MS method. Eighty-two samples were collected from markets in western Seoul. No carbendazim was detected in mungbean sprouts, however, it was detected in 6 among 59 soybean sprout samples showing a 10.2% of detection rate. Among these 6 carbendazim- detected soybean sprout samples, five exceeded the maximum residue limit presenting 83.3% of violation rate. The mean concentration in the detected samples was 0.063 mk/kg (0.012 ~ 0.104 mg/kg) and 5 of the 6 detected samples came from bulk sold products. None of the samples came from domestic products; three were from imported products and 3 were from unidentified sources. Risk assessment for the carbendazim from soybean sprout dietary intake was deemed safe and at less than 1 %Acceptable Daily Intake.

• Journal of Korean Neurosurgical Society
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• v.62 no.6
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• pp.661-670
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• 2019

Objective : Rheumatoid arthritis (RA) is known to involve the cervical spine up to 86%. It often causes cervical instability like atlantoaxial subluxation (AAS), subaxial subluxation, and vertical subluxation (VS). In order to find the relation between RA and cord compression, we will evaluate the characteristics and risk factors of basilar invagination (BI) and cervicomedullary junction (CMJ) compression. Methods : From January 2007 to May 2015, 12667 patients administrated to Hanyang University Medical Center. Four thousand three hundred eighty-six patients took cervical X-ray and 250 patients took cervical computed tomography or magnetic resonance imaging. Radiologic parameters, medication records were obtained from 242 patients. Multivariate logistic regression analysis was performed with correlation of CMJ compression, basin-dental interval (BDI), basin-posterior axial line interval (BAI), pannus formation, BI, and AAS. Results : In the point of CMJ compression, atlantodental interval (ADI), posterior-atlantodental interval, BAI, AAS, and BI are relatively highly correlated. Patients with BI have 82 times strong possibility of radiologic confirmed CMJ compression, while AAS has 6-fold and pannus formation has the 3-fold possibility. Compared to the low incidence of BI, AAS and pannus formation have more proportion in CMJ compression. Furthermore, wrist joint erosion was correlated with VS and AAS. Conclusion : BI has a very strong possibility of CMJ compression, while AAS and pannus formation have a high proportion in CMJ compression. Hence bilateral wrist joint erosion can be used as an indicator for the timing of screening test for cervical involvement. We suggest the early recommendation of cervical spine examination for the diagnosis of cervical involvement in order to prevent morbidity and mortality.

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.253-264
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• 2019

This study characterized the chemical compounds in tannin from mangium (Acacia mangium) bark extract and determined the physical-mechanical properties of glued laminated timber (glulam) made from sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), and mangium wood. The adhesives used to prepare the glulam were based on mangium tannin and phenol resorcinol formaldehyde resin. Five-layer glulam beams measuring $5cm{\times}6cm{\times}120cm$ in thickness, width, and length, respectively, were made with a glue spread of $280g/m^2$ for each glue line, cold pressing at $10.5kgf/cm^2$ for 4 h and clamping for 20 h. Condensed mangium tannin consisted of 49.08% phenolic compounds with an average molecular weight of 4745. The degree of crystallinity was 14.8%. The Stiasny number was 47.22%. The density and the moisture content of the glulams differed from those of the corresponding solid woods with mangium having the lowest moisture content (9.58%) and the highest density ($0.66g/cm^3$). The modulus of rupture for all glulam beams met the JAS 234-2003 standard but the modulus of elasticity and the shear strength values did not. Glulam beams made with tannin had high delamination under dry and wet conditions, but glulam made from sengon and jabon wood met the standard's requirements. All glulam beams had low formaldehyde emissions and were classified as $F^{****}$ for formaldehyde emissions according to the JAS 234 (2003) standard.