• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.3-17
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• 1998

The purposes of this study is to investigate the possibility of planting trees at space land in the riverside. The space land is for the green space. Calculating the plantable space in the representation section and the flood flowing stability of the existing banks based on the hydrological and meteorological data of the Kap-Chon riverbasin located in Tae-jon, the following results are drawn. (1) The flood discharges in each flow section are $698.7m^3/s$ in section 1, $654.6m^3/s$ in section 2, and $1353.3m^3/s$ in section 3 during 100 years recurrence interval. Because the designed-flood discharges in those sections are $1719.9m^3/s$, $2119.7m^3/s$, and $1512.8m^3/s$ respectively, safety for flood flowing is sufficient in existing banks. (2) The possible clearance for planting trees is 1.80m in section 1, 3.90m in section 2, and 0.01m in section 3. Planting clearance is enough in section 1 and 2. However, planting should be planned after estimating a rise-height due to the bridge piers, because many piers under riverine-highway are now on the construction in section 2. The section 3 does not have sufficient clearance for planting trees, but the planting is possible after getting enough flow area with slope by cutting the terrace land on the river artificially heightened. (3) In case of planting a tree 70cm diameter in $1m^2$ in section 1, the water level increases by 0.60m. Planting a tree in a $48m^2$ area increases the water level by 0.90m. Considering that plantable clearance is 1.8m in section 1, it is sufficient to flow safely. But if the trees are planted so compactly from the upper stream, expected heavy resistance is expected due to caught materials on the trees. So, trees have to be planted widely in upper streams but compactedly in lower streams. (4) The river width without changing, Kap-Chon's flow channel can be snaked in accordance with the nature law the wide terrace land in the riverside. Decreased flow area due to planting trees will be compensated by the inclination of terrace land. And, it is theoretically proved that the flood discharge is safe even though the terrace land on the river is parked similar to the nature. Planting trees in the terrace land of the Kap-chon river to the extent that flood flowing is not adversely affected, we can get the enjoyable park to citizens not spending expensive cost. It also contributes to the recovery of ecosystem, which gives the natural beauty of river and shade to citizens and becomes good natural-educational places for children.

• 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.

• Korean Security Journal
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• no.29
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• pp.163-191
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• 2011

Recently, the problems in school violence did not stop on the crime between the members at the school and which developed into the invasion crime of the school caused by outsiders. The school is no more the safety zone from the crime. Particularly, in the case of the elementary school, because there are nearly no people who oppose to the outside attacker and can control this, it is the place where it is vulnerable to the invasion crime. The Metropolis of Seoul implements the School Sheriff system within the jurisdiction bureau, in the public elementary school. However, actually the School Sheriff business is being managed, never applying a rule in the Security Industry Law with the main content, that is the Security Industry Law application is excluded. Because the jurisdiction on the contract of Seoul City and operating company are run, the various issues is caused. First, since it is not being considered as a security business, the commercial liability insurance for security company has no chance to applicate when the operation company and the School Sheriff have related damage generation. So the security for the indemnification of loss of the victim is weak. Second, The task of the School Sheriff is ruled just by in the individual contracts. But it is insufficient with this thing. The related duties are required some supplement like a general rule application including the obligation of the guard in the security industry law. Third, the education of the School Sheriff needs to connect with the educational programme in the security industry law. The related professional education specially needed for the prevention of school violence ought to be reserved compensation. Forth, the citizens still demand the strengthening of police patrol for the surroundings of a school in spite of the result of Seoul City's public survey. Therefore, the active relation of cooperation with the police needs to be supported legally and institutionally with the Security Industry Law application. Fifthly, the success of the School Sheriff business can be more guaranteed with the supervision of the legal and institutional device like a the Security Industry Law application or police and all sorts of administrative execution's and etc.

• Journal of Wetlands Research
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• v.15 no.1
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• pp.149-157
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• 2013

The weirs built so far are mainly overflow type weirs overflowing to the upstream. Main advantages of overflow type weirs are, effective water resources management and easy design, construction and maintenance due to many accumulated studies. However, due to the special feature of the overflow type weir where water overflows through the upstream of the weir, the silt coming from the upstream is not discharged to the downstream of the weir. This increases the river bed and reduces the reservoir capacity, and as a result, the weir loses its function. A underflow type weir with a water gate has been implemented in order to solve such sediment deposit and weir maintenance problems. However due to the design problem of recently constructed underflow type weirs, the river bed of the downstream of a weir has been scoured. And this leds to a structural problem. In this study, the flow characteristics of overflow type weirs and underflow type weir, hydraulic jump length analysis depending on change of water depth and the amount of specific energy loss generated per unit length depending on a weir type have been compared and analyzed, for the effective design and management of the weirs. The experiment results show that, when identical upstream conditions of underflow type weir and an overflow type weir were maintained, the hydraulic jump length was up to twice longer with Fr(Froude number) 3.5 of the hydraulic jump length at the underflow type weir, and the hydraulic jump length gradually decreased as the downstream water depth increased. The comparative analysis result of the amount of specific energy loss generated per unit length showed that the amount of energy loss per unit length was twice higher for an overlfow type weir than a underflow type weir. Therefore, in case of a underflow type facility, an additional energy reduction facility is determined to be necessary for safety of water construction structures.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.203-212
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• 2016

In order to investigate actual pesticide usage, this survey was carried out with farmers growing four crop groups, leaf vegetables, fruit vegetables, fruits, and rice from 2012 to 2015. Five hundred sixty farmers were selected in main crop production areas and were asked about their pesticide uses during the growing season. Investigations on pesticide damages to crop in recent 5 years showed that fruit vegetables had the highest proportion of damage at 14%, followed by rice at 11%, orchards at 11%, and leaf vegetables at 8%. Compared to the results of a pilot study which took place from 2009 to 2011, fruit vegetable damage increased by 4% while damage to rice and orchards decreased by 7-9%. This means continuous education on mixed spraying, usage methods, and precaution is required. In the survey on the safety guidelines for pesticide use, 6 items were well observed (89.0-95.0%), but one item for use of protective gear had the lowest observance (81.7%). A measure for protective gear for poisoning prevention is required. The survey of pesticide usage per area ($kg\;a.i.\;ha^{-1}$) showed that 1.65, 4.93, 10.98, and $3.16kg\;a.i.\;ha^{-1}$ of pesticides were applied to leaf vegetables (6 species), fruit vegetables (6 species), fruits (6 species), and rice, respectively, which decreased from the usage reported in the pilot study. This change was likely caused by more effective pesticides and fewer pest outbreaks; therefore, shipments of pesticides have been decreasing. In the case of paddy rice herbicides, 43 products, including butachlor, were used for $1.3kg\;ha^{-1}$. Herbicides represent 44% of pesticides used in paddy rice.

• Journal of Preventive Medicine and Public Health
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• v.22 no.3 s.27
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• pp.389-397
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• 1989

To identify the problems in child rearing practice of employed mothers in urban poor area, all of 201 women with children under 6 years old living in Yun San 3 Dong, a poor area of Pusan city, were interviewed with a questionnaire by a trained interviewer from 10th April to 10th May 1989. Among 201 women, 51 women were employed and 150 women were unemployed. Of the employed mothers 78.5% got their jobs because of economical need and 31.4% of them worker for 60-69 hours per week. Their average monthly income was 100,000-190,000 Won in 33.4% and 200,000-290,000 Won in 25.4% Breast milk was fed in 66.0% of the children of unemployed mothers while 49.0 of the children of the employed mothers were breast-fed (p<0.05). The most common reason for not breast feeding was shortage of breast milk among unemployed mothers (58.9%) but that of the employed mothers was their job(63.6%). The basic immunization for children was completed in 70.5% of children of employed mothers as compared with 82.0% of the children of the unemployed mothers were completely immunized (p>0.1). Accident experience rate of children among the employed mothers was 23.5 a and that of the children of the unemployed mothers was 17.3% . The most common cause of acident in children of the unemployed mothers was carelessness while they were playing(34.6%) but in children of the employed mothers it was traffic accident(25.0%) and falling(25.0%). Most of the traffic accidents took place while the children's brother or sister of age under 14 years were baby sitting. When the accident took place 73.1% of the unemployed mothers were just at home, but 58.3% of the employed mothers were out of home for work. In case of the employed mothers, 58.7% of their children were looked after by an adult mainly grandparents, 15.7% by the children's brothers and sisters under 14 years old, and 3.9% of the children were left alone. A majority of the unemployed mothers wanted to get a job if someone could take care of their children. To facilitate the women employment and for the safety and health of the children, good nurseries for working mothers need to be established at a cost they can afford.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.71-76
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• 1998

To know the antibiotic specificity of a Dinoflagellate, Cochlodinium polykrikoides, we investigated the survival time of C. polykrikoides against several concentrations of antibiotics and judged the selective specificity of antibiotics based on the $LT_50$ ($50\%$ of lethal time). The result showed that C. polykrikoides was sensitive to tetracycline and chloramphenicol, and resistant to polymixin-B, ampicillin, penicillin-G, dihydrostreptomycin, and neomycin. In the case of sensitive antibiotics to C. polykrikoides, tetracycline and chloramphenicol, the safety concentrations of both antibiotics were determined and the antibiotic specificity based or the plotted survival curve was analyzed. Before antibiotic treatment, we tested the antibiotic susceptibility of the contaminated bacterial population in tile culture of C. polykrikoides, and decided the proper kinds of antibiotics and concentrations before percoll-centrifugation. By percoll-centrifugation, we reduced bacteria, removed fungi, collected the algal pellet, and made axonic culture by antibiotic cascade procedure based on the result of antibiotic susceptibility test. We observed that axonic C. polykrikoides culture entered the logarthmic phase of growth when cell density was over 740 cells/ml and propagated to 5,800 cells/ml maximally. Divisions per day, k value of C. polykrikoides represented a good index for growth at the low density of cells. There was a highest k value shift before reaching to the logarithmic phase. We suggested that the preceeding highest k value shift stage is a good indicator for accurate broadcasting for red. tide blooming in the field, and the stage is also a good time for controlling red tide blooming in the filed, either.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.287-294
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• 2021

In order to expand facility agriculture and reduce greenhouse construction costs in reclaimed land, a greenhouse foundation method that satisfies economic feasibility and structural safety at the same time is required. As an alternative, the allowable bearing capacity and settlement were reviewed when the DCM(Deep cement mixing) method was applied among the soft ground reinforcement methods. To examine the applicability of the greenhouse foundation, the allowable bearing capacity and settlement were calculated by applying the theory of Terzaghi, Meyerhof, Hansen, and Schmertmann. In case of the diameter of 800mm and the width and length of the foundation of 4m, the allowable bearing capacity was 179kN/m² and the settlement was 7.25mm, which satisfies the required bearing capacity and settlement standards. The calculation results were verified through FEM(Finite element method) analysis using the Mohr-Coulomb material model. The allowable bearing capacity was 169kN/m² and the settlement was 2.52mm. The bearing capacity showed an error of 5.6% compared to calculated value, and the settlement showed and error of 65.4%. Through theoretical calculations and FEM analysis, it was confirmed that the allowable bearing capacity and settlement satisfies the design criteria as a greenhouse foundation when the width and length of the foundation were 4m. Based on the verified design values, it is expected to be able to present the foundation design criteria for greenhouses through empirical tests such as bearing capacity tests and long-term settlement monitoring.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.245-253
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• 2021

RC slab bridges account for the largest portion of deteriorated bridges in Korea. However, most RC slabs are not included in the first and second classes of bridges, which are subject to bridge safety management and maintenance. The highest damaged components in highway bridges are the subsidiary facilities including expansion joints and bearings. In particular, leakage through expansion joints causes deterioration and cracks of concrete and exposure of reinforced bars. Therefore, this study analyzed the effect of adhesion damage at expansion joints on the response of the deck in RC slab bridges. When the spacing between the expansion joints at both ends was closely adhered, cracks occurred in the concrete at both ends of the deck due to the resistance rigidity at the expansion joints. Based on the response results, the correlation analysis between displacements in the longitudinal direction of the expansion joint and concrete stress at both ends of the deck for each damage scenario was performed to investigate the effect of the occurrence of damage on the bridge behavior. When expansion joint devices at both sides were damaged, the correlation between displacement and stress showed a low correlation of 0.18 when the vehicles proceeded along all the lanes. Compared with those in the intact state, the deflections of the deck in the damaged case at both sides showed a low correlation of 0.34 to 0.53 while the vehicle passed and 0.17 to 0.43 after the vehicle passed. This means that the occurrence of cracks in the ends of concrete changed the behavior of the deck. Therefore, data-deriven damage detection could be developed to manage the damage to expansion joints that cause damage and deterioration of the deck.

• The Korean Journal of Air & Space Law and Policy
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• v.34 no.1
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• pp.3-38
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• 2019

In 1984, Congress enacted a new measure of administrative sanctions which is a civil money penalty program for violations of Aviation Act and its implementing regulations. This civil money penalty system has been in operations in lieu of suspending or revoking certificates issued by Korean government, Ministry of Land, Infrastructure, and Transport. According to the rules of Aviation Business Act or Aviation Safety Act, where the Minister of Land, Infrastructure and Transport should order an air carrier to suspend operation because of her violation under certain rules, in which case the suspension of operation is likely to cause serious inconvenience to consumers of air transport services or to harm public interest, the Minister of the department may impose an administrative monetary penalty in lieu of the suspension of operation. In this regard, airline related civil money penalties are somewhat different from those of fair trade, which is the origin of the money penalties system in Korea. Civil money penalties in the field of fair trade are imposed on executive duty violations that undermine the value of the market economy order, and focus on reimbursement of profits due to violations and compensation for unfair spending by consumers. However, in the aviation sector, breach of duty by a business operator does not simply cause the property loss of the public, but it has a direct impact on life or property of the public. In this respect, aviation penalties are more likely to be administrative sanctions or punitive measures than refunds of unfair benefits, compared to penalties in the field of fair trade. In general, civil money penalties have been highly preferred as administrative sanctions because they are subject to investigations by administrative experts and thus, efficiency can be ensured and execution is quicker than judicial procedures. Moreover, in Korea, because punitive civil damages cannot awarded by the courts, the imposition of civil money penalties is recognized as a means of realizing social justice by recognizing the legal feelings of the people. However, civil money penalties are administrative sanctions, and in terms of effectiveness, they are similar to criminal fines, which are a form of punishment. Inadequate legislation and operation of penalties imposition may cause damage to the value of Constitution. Under the above recognition, this paper has been described for the purpose of identifying the present status of the civil money penalties imposition system and operating status in the area of air transport under the laws and regulations in Korea. Especially, this paper was focused on exploring the problem and improvement direction of Korean system through the comparative study with foreign laws and regulations.