• Journal of the Korean Association of Geographic Information Studies
• /
• v.20 no.2
• /
• pp.60-74
• /
• 2017

To facilitate prevention of highly pathogenic avian influenza (HPAI), a GIS is widely used for monitoring, investigating epidemics, managing HPAI-infected farms, and eradicating the disease. After the outbreak of foot-and-mouth disease in 2010 and 2011, the government of the Republic of Korea (ROK) established the GIS-based Korean Animal Health Integrated System (KAHIS) to avert livestock epidemics, including HPAI. However, the KAHIS is not sufficient for controlling HPAI outbreaks due to lack of responsibility in fieldwork, such as sterilization of HPAI-infected poultry farms and regions, control of infected animal movement, and implementation of an eradication strategy. An outbreak prediction model to support efficient HPAI control in the ROK is proposed here, constructed via analysis of HPAI outbreak patterns in the ROK. The results show that 82% of HPAI outbreaks occurred in Jeolla and Chungcheong Provinces. The density of poultry farms in these regions were $2.2{\pm}1.1/km^2$ and $4.2{\pm}5.6/km^2$, respectively. In addition, reared animal numbers ranged between 6,537 and 24,250 individuals in poultry farms located in HPAI outbreak regions. Following identification of poultry farms in HPAI outbreak regions, an HPAI outbreak prediction model was designed using factors such as the habitat range for migratory birds(HMB), freshwater system characteristics, and local road networks. Using these factors, poultry farms which reared 6,500-25,000 individuals were filtered and compared with number of farms actually affected by HPAI outbreaks in the ROK. The HPAI prediction model shows that 90.0% of the number of poultry farms and 54.8% of the locations of poultry farms overlapped between an actual HPAI outbreak poultry farms reported in 2014 and poultry farms estimated by HPAI outbreak prediction model in the present study. These results clearly show that the HPAI outbreak prediction model is applicable for estimating HPAI outbreak regions in ROK.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.9 no.2
• /
• pp.64-72
• /
• 2004

We measured the vertical profiles of $O_2$, H$_2$S, and pH in sediment pore water beneath marine cage fish farms using a microsensor with a 25 ${\mu}{\textrm}{m}$ sensor tip size. The sediments are characterized by high organic material load. The oxygen consumption, hydrogen sulfide oxidation, and sulfate reduction rates in the microzonations (derived from the vertical distribution of chemical species concentration) were estimated by adapting a simple one-dimensional diffusion-reaction model. The oxygen penetration depth was 0.75 mm. The oxic microzonations were divided into upper and lower layers. Due to hydrogen sulfide oxidation within the oxic zone, the oxygen consumption rate was higher in the lower layer. The total oxygen consumption rate integrated with reaction zone depth was estimated to be 0.092 $\mu$mol $O_2$cm$^{-2}$ hr$^{-1}$ . The total hydrogen sulfide oxidation rate occurring within 0.7 mm thickness was estimated to be 0.030 $\mu$mo1 H$_2$S cm$^{-2}$ hr$^{-1}$ , and its turnover time in the oxic sediment layer was estimated to be about 2 minutes. This suggests that hydrogen sulfide was oxidized by both chemical and microbial processes in this zone. The molar consumption ratio, calculated to be 0.84, indicates that either other electron accepters exit on hydrogen sulfide oxidation, or elemental sulfur precipitation occurs near the $O_2$- H$_2$S interface. Total sulfate reduction flux was estimated to be 0.029 $\mu$mol cm$^{-2}$ hr$^{-1}$ , which accounted for more than 60% of total $O_2$ consumption flux. This result implied that the degradation of organic matter in the anoxic layer was larger than in the oxic layer.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.785-795
• /
• 2018

The International Maritime Organization (IMO) has recognized the risk of hull fouling and announced '2011 Guidelines for the control and management of ship's biofouling to minimize the transfer of invasive aquatic species'and is planning international regulations to enforce them in the future. In this study, to effectively respond to future international regulation, we introduce the case of leading countries related to management of hull fouling and also investigate environmental risk assessment techniques for in-water cleaning. Australia and New Zealand, the leading countries in hull fouling management, have established hull fouling regulations through biological and chemical risk assessment based on in-water cleaning scenarios. Most European countries without their government regulation have been found to perform in-water cleaning in accordance with the IMO's hull fouling regulations. In the Republic of Korea, there is no domestic law for hull fouling organisms, and only approximately 17 species of marine ecological disturbance organisms, are designated and managed under the Marine Ecosystem Law. Since in-water cleaning is accompanied by diffusion of alien species and release of chemical substances into aquatic environments, results from biological as well as chemical risk assessment are performed separately, and then evaluation of in-water cleaning permission is judged by combining these two results. Biological risk assessment created 40 codes of in-water cleaning scenarios, and calculated Risk Priority Number (RPN) scores based on key factors that affect intrusion of alien species during in-water cleaning. Chemical risk assessment was performed using the MAMPEC (Marine Antifoulant Model to Predict Environmental Concentrations), to determine PEC and PNEC values based on copper concentration released during in-water cleaning. Finally, if the PEC/PNEC ratio is >1, it means that chemical risk is high. Based on the assumption that the R/V EARDO ship performs in-water cleaning at Busan's Gamcheon Port, biological risk was estimated to be low due to the RPN value was <10,000, but the PEC/PNEC ratio was higher than 1, it was evaluated as impossible for in-water cleaning. Therefore, it will be necessary for the Republic of Korea to develop the in-water cleaning technology by referring to the case of leading countries and to establish domestic law of ship's hull fouling management, suitable for domestic harbors.

• Korean journal of applied entomology
• /
• v.29 no.3
• /
• pp.209-215
• /
• 1990

Some preliminary studies were conducted to find out whether the levee-burning could justifiable for the suppression of insect pests, particularly the smaller brown planthopper (Laodelphax striatellus F.). Density surveys on pests and their enemies (mostly spiders) were carried out upto the mid May at an experimental paddy field located in Suwon after of it's levee $(72\times1m)$ was burned on Feb. 20, 1987. Results were discussed in relation to density recovering of both pests and their possible enemies (spiders) and summarized as below. Not a single individual of any pest or enemy was found from the levee upto sometime after the levee-burning. Grasses started to grow more vigorously in burned ares than in unburned upto about 60 days after the burning. And densities of both pest and enemies grew higher in burned areas than in unburned from about 75 days after the burning (in Early may). It is suspected that all individuals of pests and enemies fond from the burned areas could have immigrated from the surrounding areas. If levee-burning was carried out in much wider areas, much longer time would be needed to recover the density of both pests and enemies to the center region of the burning. Wingless spiders would require even longer time than winged pest species to re-establish in the center region of the widely burned field. Pirata subpiraticus, the most abundant spider species in Korean paddy fields, starts to move about and searches for food at above $9^{\circ}C$ which is somewhat lower than the critical temperature for the pest species. Thus P. subpiraticus would require more food than other pest species early in the spring, and therefore, it would have lower probability to survive than pest species particularly in burned areas. Experiments for pest suppression with levee-burning would better be carried on in much wider areas, and its justification seems to be discussed after man other disciplines related to both pests and their natural enemies were throughly studied together with their density surveys. However, according to the present point of vie, the opinion that levee-burning is helpful for controlling pests which over winter on levee areas could not be justifiable.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.18 no.2
• /
• pp.89-103
• /
• 2013

National demands for the ocean forecasting system have been increased to support economic activity and national safety including search and rescue, maritime defense, fisheries, port management, leisure activities and marine transportation. Further, the ocean forecasting has been regarded as one of the key components to improve the weather and climate forecasting. Due to the national demands as well as improvement of the technology, the ocean forecasting systems have been established among advanced countries since late 1990. Global Ocean Data Assimilation Experiment (GODAE) significantly contributed to the achievement and world-wide spreading of ocean forecasting systems. Four stages of GODAE were summarized. Goal, vision, development history and research on ocean forecasting system of the advanced countries such as USA, France, UK, Italy, Norway, Australia, Japan, China, who operationally use the systems, were examined and compared. Strategies of the successfully established ocean forecasting systems can be summarized as follows: First, concentration of the national ability is required to establish successful operational ocean forecasting system. Second, newly developed technologies were shared with other countries and they achieved mutual and cooperative development through the international program. Third, each participating organization has devoted to its own task according to its role. In Korean society, demands on the ocean forecasting system have been also extended. Present status on development of the ocean forecasting system and long-term plan of KMA (Korea Meteorological Administration), KHOA (Korea Hydrographic and Oceanographic Administration), NFRDI (National Fisheries Research & Development Institute), ADD (Agency for Defense Development) were surveyed. From the history of the pre-established systems in other countries, the cooperation among the relevant Korean organizations is essential to establish the accurate and successful ocean forecasting system, and they can form a consortium. Through the cooperation, we can (1) set up high-quality ocean forecasting models and systems, (2) efficiently invest and distribute financial resources without duplicate investment, (3) overcome lack of manpower for the development. At present stage, it is strongly requested to concentrate national resources on developing a large-scale operational Korea Ocean Forecasting System which can produce open boundary and initial conditions for local ocean and climate forecasting models. Once the system is established, each organization can modify the system for its own specialized purpose. In addition, we can contribute to the international ocean prediction community.

• Journal of the Korean Wood Science and Technology
• /
• v.39 no.1
• /
• pp.68-74
• /
• 2011

Cauliflower mushroom ($Sparassis$ $crispa$) is being cultivated as a functional mushroom since the mushroom contains larger amount of ${\beta}$-glucan than other edible or medicinal mushrooms. In this study, as a fundamental study for the cultivation process of cauliflower mushroom, we assayed the mycelial growth and the productivity of the mushroom cultivated on the sawdust-based medium made of larch ($Larix$ $kaempferi$) by 4 kinds of medium densities and 6 kinds of particle sizes. Low densities of sawdust-based media (0.68~0.72 g/$cm^3$) showed high variations in mycelial growth at early stage on sawdust-based medium. The coefficient of variance for the mycelial growth decreased from higher than 40% at the 3rd week to lower than 10% at the 7th week. High density of sawdust-based medium (0.80 g/$cm^3$) showed relatively lower variation in the mycelial growth at early stage with less than 30% of coefficient of variance, the high density of sawdust-based medium was thought to be quite stable compared to the lower densities of sawdust-based medium. From the viewpoint of mushroom productivity especially for the goods (excluding bottom of fruiting body), 0.76 g/$cm^3$ was better than any other densities; the return rates of fruiting body from each medium were 12.2, 13.6, 13.1, and 12.0% for 0.80, 0.76, 0.72, and 0.68 g/$cm^3$, respectively. By the way, it took about 40 days for harvesting from primordium formation with the sawdust-based medium excluded the particles less than 1 mm, while it took about 70 days with the medium including the particles less than 1 mm. The yield from the sawdust-based medium with the particles less than 1 mm was also quite less than any other sawdust-based medium especially for the goods. Therefore, we recommend that the sawdust-based medium with larch for the cultivation of cauliflower mushroom be prepared as 0.76 g/$cm^3$ in medium density with excluding the particles less than 1 mm.

• Tuberculosis and Respiratory Diseases
• /
• v.40 no.5
• /
• pp.519-531
• /
• 1993

Background: Lymphangioleiomyomatosis(LAM) is a very rare disease occurring in women of reproductive age and leading to progressive respiratory failure despite therapy. But the natural history of this disease is uncertain and although anti-estrogenic agents have been used for more than twenty years, it's efficacy is still in debate. This study was performed to enhance understanding of this fatal disease in Korea by examining clinical, radiological, and pathologic findings of all the previously reported cases of LAM on Korea along with four new cases of LAM whom we report in this paper. Method: Out of twlve cases of LAM previously unpublished and published in domestic papers, two cases whose diagnoses were considered doubtful after review of clinical, radiological, and pathologic findings at "Asian Congress on Lymphangioleiomyomatosis" at Kyoto, Japan in feburary of 1993 were excluded from this study. Six cases which were reported previously and four new cases of LAM whom we report in this paper were analysed for the clinical, radiological, and pathologic characteristics. Results: All ten patients were women with mean age of $33{\pm}7$. The most common symptom was exertional dyspnea and most patients had history of pneumothoraces. Pulmonary function tests showed decreased diffusing capacity. on high resolution computed tomography(HRCT), all the cases had characteristic cysts. Most of the patients did not respond to hormonal therapy. Conclusion: In women of reproductive age, presenting with dyspnea who has a history of pneumothorax, LAM should always be considered as one of the diagnostic possibilities. If suspected, HRCT should be done to look for characteristic cysts and if needed, open lung biopsy should be done to confirm the diagnosis.

• Progress in Medical Physics
• /
• v.24 no.1
• /
• pp.1-24
• /
• 2013

As image-guided radiation therapy (IGRT) has been commonly used for more accurate patient setup and monitoring tumor movement during radiation therapy, the necessity for management of imaging dose is increased. However, it has not been an interest issue to radiation therapy communities because the imaging dose is much lower than the therapeutic dose. However, since the cumulative dose from 4DCT and repeated imaging for daily setup verificationin would not be ignorable, appropriate dose management based on ALARA (As Low As Reasonably Achievable) principle is required. In this study, we aimed that (1) survey on imaging equipments and modalities used for IGRT, (2) estimation of IGRT imaging dose depending on treatment types and equipments, (3) collecting data of effective dose on treatment sites from each equipment and imaging protocol, and thus finally provide guideline for imaging dose reduction and optimization.

• Journal of the Mineralogical Society of Korea
• /
• v.25 no.4
• /
• pp.185-195
• /
• 2012

Due to the high reduction and sorption capacity as well as the large specific surface area, nanosized mackinawite (FeS) is useful in reductively transforming chlorinated organic pollutants and sequestering toxic metals and metalloids. Due to the dynamic nature in its colloid stability, however, nanosized FeS may be washed out with the groundwater flow or result in aquifer clogging via particle aggregation. Thus, these nanoparticles should be modified such as to be built into permeable reactive barriers. This study employed coating methods in efforts to facilitate the installation of permeable reactive barriers of nanosized mackinawite. In applying the methods, nanosized mackinawite was coated on non-treated silica sand (NTS) and chemically treated silica sand (CTS). For both silica sands, the maximum coating of mackinawite occurred around pH 5.4, the condition of which was governed by (1) the solubility of mackinawite and (2) the surface charge of both silica and mackinawite. Under this pH condition, the maximum coating by NTS and CTS were found to be 0.101 mmol FeS/g and 0.043 mmol FeS/g respectively, with such elevated coatings by NTS likely linked with impurities (e.g., iron oxides) on its surface. Arsenite sorption experiments were performed under anoxic conditions using uncoated silica sands and those coated with mackinawite at the optimal pH to compare their reactivity. At pH 7, the relative sorption efficiency between uncoated NTS and coated NTS changed with the initial concentration of arsenite. At the lower initial concentration, uncoated NTS showed the higher sorption efficiency, whereas at the higher concentration, coated NTS exhibited the higher sorption efficiency. This could be attributed to different sorption mechanisms as a function of arsenite concentration: the surface complexation of arsenite with the iron oxide impurity on silica sand at the low concentration and the precipitation as arsenic sulfides by reaction with mackinawite coating at the high concentration. Compared to coated NTS, coated CTS showed the lower arsenite removal at pH 7 due to its relatively lower mackinawite coating. Taken together, our results indicate that NTS is a more effective material than CTS for the coating of nanosized mackinawite.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.18 no.2
• /
• pp.94-101
• /
• 2015

To mitigate the greenhouse gas emission, many carbon capture and storage projects are underway all over the world. In Korea, many studies focus on the storage of $CO_2$ in the offshore sediment. Assurance of safety is one of the most important issues in the geological storage of $CO_2$. Especially, the assessment of possibility of leakage and amount of leaked $CO_2$ is very crucial to analyze the safety of marine geological storage of $CO_2$. In this study, the leakage of injected $CO_2$ through fault was numerically studied. TOUGH2-MP ECO2N was used to simulate the subsurface behavior of injected $CO_2$. The storage site was 150 m thick saline aquifer located 825 m under the continental shelf. It was assumed that $CO_2$ leak was happened through the fault located 1,000 m away from the injection well. The injected $CO_2$ could migrate through the aquifer by both pressure difference driven by injection and buoyancy force. The enough pressure differences made it possible the $CO_2$ to migrate to the bottom of the fault. The $CO_2$ could be leaked to seabed through the fault due to the buoyancy force. Prior to leakage of the injected $CO_2$, the formation water leaked to seabed. When $CO_2$ reached the seabed, leakage of formation water stopped but the same amount of sea water starts to flow into the underground as the amount of leaked $CO_2$. To analyze the effect of injection rate on the leakage behavior, the injection rate of $CO_2$ was varied as 0.5, 0.75, and $1MtCO_2/year$. The starting times of leakage at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 11.3, 15.6 and 23.2 years after the injection, respectively. The leakage of $CO_2$ to the seabed continued for a period time after the end of $CO_2$ injection. The ratios of total leaked $CO_2$ to total injected $CO_2$ at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 19.5%, 11.5% and 2.8%, respectively.