• Economic and Environmental Geology
• /
• v.43 no.6
• /
• pp.555-564
• /
• 2010

Remediation process by using the bio-carrier (beads) with dead Bacillus sp. B1 and polysulfone was investigated for heavy metal contaminated groundwater. Sorption batch experiments using the bio-carrier were performed to quantify the heavy metal removal efficiencies from the contaminated solution. The analyses using SEM/EDS and TEM for the structure and the characteristic of precipitates on/inside the beads were also conducted to understand the sorption mechanism by the bio-carrier. Various amounts of freeze-dried dead Bacillus sp. B1 were mixed with polysulfone + DMF(N,N-dimethylformamide) solution to produce the bio-carrier (beads; less than 2mm in diameter) and 5% of Bacillus sp. B1 in the bio-carrier was optimal for Pb removal in the solution. The removal efficiency ratings of the bio-carrier for Pb, Cu and Cd were greater than 80% after adding 2g of bio-carrier in 50ml of aqueous solution (<10mg/L of each heavy metal concentration). Reaction time of the bio-carrier was very fast and most of the sorption reaction for heavy metals were completed within few hours. Batch experiments were duplicated at various pH conditions of aqueous solutions and Cu and Pb removal efficiencies highly maintained at wide pH ranges (pH 2-12), suggesting that the bio-carrier can be useful to clean up the acidic waste water such as AMD. From SEM/EDS and TEM analyses, it was observed that the bio-carrier was spherical shape and was overlapped by many porous layers. During the sorption experiment, Pb was crystallized on the surface of porous layers and also was mainly concentrated at the boundary of Bacillus sp. B1 stroma and polysulfone substrate, showing that the main mechanism of the bio-carrier to remove heavy metals is the sorption on/inside of the bio-carriers and the bio-carriers are excellent biosorbents for the removal of heavy metal ions from groundwater.

• Journal of Broadcast Engineering
• /
• v.13 no.2
• /
• pp.200-213
• /
• 2008

H.264| MPEG-4 AVC is a new video codingstandard defined by JVT (Joint Video Team) which consists of ITU-T and ISO/IEC. Many techniques are adopted fur the compression efficiency: Especially, an intra prediction in an inter frame is one example but it leads to excessive amount of encoding time due to the decision of a candidate mode and a RDcost calculation. For this reason, a fast determination of the best intra prediction mode is the main issue for saving the encoding time. In this paper, by using the result of statistical relation between intra $16{\times}16$ and $4{\times}4$ intra predictions, the number of candidate modes for $4{\times}4$ intra prediction is reduced. Firstly, utilizing motion vector obtained after inter prediction, prediction of a block mode for each macroblock is made. If an intra prediction is needed, the correlation table between $16{\times}16$ and $4{\times}4$ intra predicted modes is created using the probability during each I frame-coding process. Secondly, using this result, the candidate modes for a $4{\times}4$ intra prediction that reaches a predefined specific probability value are only considered in the same GOP For the experiments, JM11.0, the reference software of H.264|MPEG-4 AVC is used and the experimental results show that the encoding time could be reduced by 51.24% in maximum with negligible amounts of PSNR drop and bitrate increase.

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

• Journal of Soil and Groundwater Environment
• /
• v.6 no.3
• /
• pp.53-59
• /
• 2001

There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

• Journal of Legislation Research
• /
• no.44
• /
• pp.757-799
• /
• 2013

Ever since Korea and Vietnam reestablished diplomatic relations, the two countries'bond has become stronger than ever, augmenting the range of exchange between them in almost every possible field including politics, economy, society, and culture at such a high speed. Among many, an increase in number of Vietnamese immigrant women in international marriage is worthy of close attention. Since 2010, Vietnamese has topped the proportion of total foreign women married to Korean men, having surpassed Chinese. Nonetheless, the quick international marriage between Korean men and Vietnamese women, which usually happens without sufficient time to get to know about different cultures and languages, has not only raised problems for people concerned, but numerous social issues as well. Recognizing these problems, a number of government departments have provided various support on policies and legal issues toprotect multicultural families as a means of social integration and settlement support. Nevertheless, the support policies until now have been generalizing all of the immigrant women in international marriage as people subject to protection. Thus, considering every immigrant women as people in need, and trying to help them with various social issues have caused the government a high cost and low efficiency. This thesis emphasizes the point that through the cases of Vietnamese immigrant women in international marriage, there should be a specific support plan for specific people in need, reflecting various traits of different cultures and societies, in order to ease their settlement in Korea. Moreover, it suggests detailed plans for improvements on legal and institutional problems. Although the Vietnamese government forbids commercial agents for international marriage, many of agencies are still active and to help the immigrant women, who desire to return and resettle in Vietnam in case of divorce, this thesis suggests legal and institutional remedies for Korean and Vietnamese government. The composition of the thesis follows below: Part II on social and cultural traits of international marriage between Korean men and Vietnamese women. Part III on institutional problems and plans for improvements regarding settlement of immigrant women in international marriage. Part IV on legal and institutional problems and plans for improvements regarding divorced immigrant women and their return to Vietnam. Part V on conclusion. Divorce is not a flaw anymore nowadays, but in case of Vietnamese immigrant women ininternational marriage, an inadequate legal system hampers their resettlement process. Cases of not being ableto remove their own names from the family register due to poor financial and legal abilities are often identified and it is both the Vietnamese and Korean governments'duty to acquit their ethical responsibilities by seeking ways to institutionally and financially support them.

• Journal of Korea Water Resources Association
• /
• v.54 no.12
• /
• pp.1243-1254
• /
• 2021

For water resources operation or agricultural water management, it is important to accurately predict evapotranspiration for a long-term future over a seasonal or monthly basis. In this study, reference evapotranspiration forecast (up to 12 months in advance) was performed using statistically predicted monthly temperatures and temperature-based Hamon method for the Han River basin. First, the daily maximum and minimum temperature data for 15 meterological stations in the basin were derived by spatial-temporal downscaling the monthly temperature forecasts. The results of goodness-of-fit test for the downscaled temperature data at each site showed that the percent bias (PBIAS) ranged from 1.3 to 6.9%, the ratio of the root mean square error to the standard deviation of the observations (RSR) ranged from 0.22 to 0.27, the Nash-Sutcliffe efficiency (NSE) ranged from 0.93 to 0.95, and the Pearson correlation coefficient (r) ranged from 0.97 to 0.98 for the monthly average daily maximum temperature. And for the monthly average daily minimum temperature, PBIAS was 7.8 to 44.7%, RSR was 0.21 to 0.25, NSE was 0.94 to 0.96, and r was 0.98 to 0.99. The difference by site was not large, and the downscaled results were similar to the observations. In the results of comparing the forecasted reference evapotranspiration calculated using the downscaled data with the observed values for the entire region, PBIAS was 2.2 to 5.4%, RSR was 0.21 to 0.28, NSE was 0.92 to 0.96, and r was 0.96 to 0.98, indicating a very high fit. Due to the characteristics of the statistical models and uncertainty in the downscaling process, the predicted reference evapotranspiration may slightly deviate from the observed value in some periods when temperatures completely different from the past are observed. However, considering that it is a forecast result for the future period, it will be sufficiently useful as information for the evaluation or operation of water resources in the future.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.4
• /
• pp.60-77
• /
• 2021

From 2007 to 2011, four Goryeo Dynasty vessels, namely the Taean treasure ship, Taean Mado Shipwreck No.1, No.2, No.3 were discovered in Taean area, Chungcheongnam-do province. From the shipwrecks, 175 pieces of mokkan (wooden tablet) were excavated. These mokkans are the only case of Goryeo Dynasty and represent the unique usage of mokkan as cargo tags, after the paper replaced the wooden tablets as writing materials. The Taean mokkans provide details, such as the year, recipient, port of origin, types of the cargo, quantity and unit, the name of the responsible person for shipment. Thus, they enable us to speculate about the characteristics of the cargo. Furthermore, through studying the writing style, form, material and manufacturing method, researchers can extract which form and characteristics were favored at that time. The Taean mokkans have no preset style for writing. Therefore, they can be written selectively and freely. And since the mokkan were attached to cargos, mokkans with furrows on upper side were favored, and efficiency and simplification of the manufacturing process were priorities in making mokkans. The Taean mokkans can be compared to those from the Shinan ship and the Quanzhou ship because those are of the same era and use. On the writing styles and information, Chinese mokkans are focused on the cargo owners, while The Taean mokkan includes more detailed information, such as the recipients. In forms, Chinese mokkans have maximum thickness of 1.0 centimeter and have pointed edges in lower parts, while mokkans from Taean do not have fixed thickness or edges. Furthermore, Chinese mokkans and Korean mokkans have different styles from manufacturing methods and material selections. These differences between Chinese and Goryeo mokkan are related to the differences between littoral-transport Goryeo ships and ocean-transport Chinese ships, such as shipping distances, types of cargo, shipping systems, packing methods, and transport operators. At the moment, because there are only small amount of data and materials of Chinese mokkan, comparative studies regarding Goryeo and Chinese mokkan can only be fragmentary. However, this article can be a base from which to expand the scope of Goryeo mokkan studies.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.2
• /
• pp.31-40
• /
• 2019

In Korea, 51,013 thousand tons of livestock manure was generated in 2018. A total of 46,530 thousand tons, which is 91.2% of the total amount of livestock manure generated, was treated by composting(40,647 thousand tons) or liquid fertilization(5,884 thousand tons) method. At present, the policy of livestock manure treatment in Korea is to make livestock manure into organic fertilizer(compost, liquid fertilizer) and then to applicate it on agricultural land. And this policy is very effective in terms of livestock manure treatment and nutrient recycling. However, considering the steadily declining farmland area for decades, the use of livestock manure compost could be limited in the future. There is also concern that local nutrient overloading, nutrient management regulation, and restrictions on the number of livestock may become serious problem for livestock manure treatment. In addition, there are some opinions that nutrient derived from livestock manure may flow into tributaries of major dams. In recent years, there has been a suspicion that fine dust may be generated from livestock manure compost. In recent years, the use of livestock manure fertilizer has been rapidly increasing, there is a growing demand of the development of new technologies for livestock manure treatment. Especially, cow excretes a larger amount of manure than other livestock, so that the efficiency of development of new technology for cow manure treatment will be high. Therefore, in this study, the combustion characteristics of cow manure pellet were investigated in order to analyzed whether cow manure could be used as source of solid fuel. During the combustion test, the weight loss of the cow manure pellet began to increase when the temperature of the combustion chamber reached $300^{\circ}C$. The ratio of $H_2$, $CH_4$, CO in the pyrolysis gas produced in the pyrolysis process of cow manure pellet were 6.65~11.62%, 0.58~1.54 and 11.47~14.07%, respectively.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.13 no.6
• /
• pp.49-62
• /
• 2018

The purpose of this study is to develop an assessment index for the selection of promising start-ups, which will enhance the efficiency of program that support start-ups. In order to develop assessment models for selecting start-ups, three major research steps were conducted. First, this study attempted to theoretically redefine the assessment index from the perspective of the Balanced Scorecard (BSC) through a literature review. Second, major assessment index were derived using Delphi technique for experts in start-up areas. Third, weights were derived by applying AHP technique to calculate the importance of each index. The results of this study are summarized as follows. First, this study attempted to apply the assessment model for selecting start-ups from the Balanced Scorecard (BSC) view through the previous study review. Second, the final major questions were derived with sufficient opinions collected and structured survey of leading start-up experts in areas related to research subjects and elicited the most representative questions. Third, the results of applying the weights of the main selected assessment index, commercialization viewpoint is the most priority, followed by market view, technology development viewpoint, and organizational capability viewpoint. In the middle section, th ability to make products in the commercialization viewpoint, market competitiveness in the market, product discrimination capacity in the technology development perspective, and the ability of the entrepreneur in the organizational capacity perspective were important. Overall important items were found to be in the order of the capabilities of entrepreneurs, market competitiveness, product fire capability, and product discrimination. The importance of small items was highest priority for comparative excellence of competing products, and the degree of marketability, capacity of entrepreneurship, ability to raise capital, desire for entrepreneurship, and passion were shown. The results of this study presented a conceptual alternative to the preceding study on the development of existing selection assessment indexes. And it provides meaningful and important implications as an attempt to develop more sophisticated indicators by overcoming the limitations of empirical research on only some of the evaluation metrics.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.479-487
• /
• 2018

The purpose of this study is to analyze photochemical activity of nursery seedlings under drought stress, using chlorophyll fluorescence reaction analysis. Young nursery seedlings of tomato (Lycopersicon esculentum Mill.) and cucumber (Cucumis sativa L.), were grown under drought stress for 8 days. Analysis of chlorophyll fluorescence reaction (OJIP) and parameters, were performed to evaluate photochemical fluctuation in nursery seedlings under drought stress. Chlorophyll fluorescence reaction analysis showed maximal recorded fluorescence (P) decreased from the 5 day after treatment in tomato seedlings, while an amount of chlorophyll fluorescence increased at the J-I step. Thus, physiological activity was reduced. In cucumber seedlings, maximal recorded fluorescence (P) and maximal variable fluorescence ($F_V$) lowered from the 4 day after treatment, and chlorophyll fluorescence intensity of J-I step increased. Chlorophyll fluorescence parameter analysis showed electron transfer efficiency of PSII and PSI were significantly inhibited with decreasing $ET2_O/RC$ and $RE1_O/RC$ from the 5 day after treatment, in tomato seedlings and from the 4 day after treatment, in cucumber seedlings. $ET2_O/RC$ and $PI_{ABS}$ significantly changed. In conclusion, 6 indices such as $F_V/F_M$, $DI_O/RC$, $ET2_O/RC$, $RE1_O/RC$, $PI_{ABS}$ and $PI_{TOTAL}ABS$ were selected for determining drought stress in nursery seedlings. Drought stress factor index (DFI) was used to evaluate whether the crop was healthy or not, under drought stress. Cucumber seedlings were less resistant to drought stress than tomato seedlings, in the process of drought stress.