• Journal of the Korea Society for Simulation
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• v.32 no.4
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• pp.69-76
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• 2023

To improve the financial stability of the National Pension, an appropriate target rate of return should be established based on pension liabilities, and asset allocation policies should be formulated accordingly. The purpose of this study is to calculate the target rate of return considering the contributions of subscribers and the pension benefits, and based on this, derive an asset allocation. To do this, we utilized the internal rate of return methodology to calculate the target rate of return for each cohort. And then, we employed a Monte Carlo simulation-based re-sampling mean-variance model to derive asset allocation for each cohort that satisfy the target rate of return while minimizing risks. Our result shows that the target rate of return for each cohort ranged from 6.4% to 6.85%, and it decreased as the generations advanced due to a decrease in the income replacement rate of the National Pension. Consequently, the allocation of risky assets, such as stocks, was relatively reduced in the portfolios of future generations. This study holds significance in that it departs from the macroeconomic-based asset allocation methodology and proposes investments from an asset-liability management perspective, which considers the characteristics of subscribers' liabilities.

• Journal of Korea Water Resources Association
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• v.57 no.5
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• pp.311-320
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• 2024

Climate change has been intensifying drought frequency and severity. Such prolonged droughts reduce reservoir levels, thereby exacerbating drought impacts. While previous studies have focused on optimizing reservoir operations using historical data to mitigate these impacts, their scope is limited to analyzing past events, highlighting the need for predictive methods for future droughts. This research introduces a novel approach for predicting minimum inflow at the Seomjingang dam which has experienced significant droughts. This study utilized the Stochastic Analysis Modeling and Simulation (SAMS) 2007 to generate inflow sequences for the same period of observed inflow. Then we simulate reservoir operations to assess firm yield and predict minimum inflow through synthetic inflow analysis. Minimum inflow is defined as the inflow where firm yield is less than 95% of the synthetic inflow in many sequences during periods matching observed inflow. The results for each case indicated the firm yield for the minimum inflow is on average 9.44 m³/s, approximately 1.07 m³/s lower than the observed inflow's firm yield of 10.51 m³/s. The minimum inflow estimation can inform reservoir operation standards, facilitate multi-reservoir system reviews, and assess supplementary capabilities. Estimating minimum inflow emerges as an effective strategy for enhancing water supply reliability and mitigating shortages.

• Journal of Platform Technology
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• v.11 no.5
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• pp.59-71
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• 2023

This paper proposes a method of estimating the illumination chromaticity of a scene in which an image is taken. Storring and Bianco proposed a method of estimating illuminant chromaticity using skin color. Storring et al. used skin color distribution characteristics and black body locus, but there is a problem that the link between the locus and CIE-xy data is reduced. Bianco et al. estimated the illuminant chromaticity by comparing the skin color distribution in standard lighting with the skin color distribution in the input image. This method is difficult to measure and secure as much skin color as possible in various illumination. The proposed method can estimate the illuminant chromaticity for any input image by analyzing the relationship between the skin color information and the illuminant chromaticity. The estimation method is divided into an analysis stage and a test stage, and the data set was classified into an analysis group and a test group and used. Skin chromaticity is calculated by obtaining skin color areas from all input images of the analysis group, respectively. A mapping is obtained by analyzing the correlation between the average set of skin chromaticity and the reference illuminant chromaticity set. The calculated mapping is applied to all input images of the analysis group to estimate the illuminant chromaticity, calculate the error with the reference illuminant chromaticity, and repeat the above process until there is no change in the error to obtain a stable mapping. The obtained mapping is applied to the test group images similar to the analysis stage to estimate the illuminant chromaticity. Since there is no independent data set containing skin area and illuminant reference information, the experimental data set was made using some of the images of the Intel TAU data set. Compared to Finlayson, a similar theory-based existing method, it showed performance improvement of more than 40%, Zhang 11%, and Kim 16%.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.69-76
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• 2010

After feeding mixed samples, VS ranged from 60 to 80% of total costs in 15 days. EC ranged from1.21 to 2.45, 1.25 to 2.1 and 1.2 to 1.88mS/cm when worms were fed with a mixture of by-products of tidal current and sewage sludge, a mixture of by-products of algae producy, and food wastes and a mixture of by-products of algae producy, sewage sludge and food wastes. That means the kinds of mixture don't have any negative impacts on worms survival. With the feed with a mixture of by-products of algae producy and food wastes and a mixture of by-products of algae producy, sewage sludge and food wastes, pH shows stable 5.4 to 6.7, and 6.2 to 7.4 where is suitable for worms. But a mixture of by-products of algae producy and sewage sludge is out of proper scope for raising worms, in other words, extra care will be necessary. In case of Eh, a mixture of by-products of algae producy and sewage sludge make eh negative (-) in early stage so also when feeding worms, also extra care will be needed. NaCl ranged from 0.32 to 0.82% or form 0.23 to 0.61% when a mixture of by-products of algae producy and food wastes and a mixture of by-products of algae producy, sewage sludge and food wastes were fed. So taking care of salts will be essential whenever feeding.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.265-273
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• 2015

It is the better to take preventative measures against the natural intrusion in advance from invasive alien species that reduce biodiversity and cause economic loss to humans. If the prevention of intrusion and spread fails, we need to make active control and eradication. This study aims to introduce nutria (Myocastor coypus) control cases performed in the United Kingdom and the United States and to provide information for the contribution of nutria management measure improvements. The nutria eradication campaign in the United Kingdom was developed as a long-term plan based on sufficient understanding on the management target and objective and suitable support. Sufficient information on nutria was accumulated and the management strategy was flexibly modified according to the changes in management that were proactively reflected in the field. Regarding the eradication project at Chesapeake Bay in the United States, based on long-term ecological information, more advanced capture technology than in the United Kingdom were introduced and the eradication plan, strategy and implementation were configured by analyzing the strengths and weaknesses of the eradication campaign in the United Kingdom. The successful cases in the United Kingdom and the United State provide an information on how to improv the nutria management measure. For the eradication of nutria, it is necessary to reach a consensus between stakeholders and to form a consultative group between related organizations for periodic communication. Opinions on the field must be actively accepted in the consultation process for strategy and policy decision, and the eradication plan needs to be developed based on a management index. The eradication plan is required to be managed, evaluated and adjusted in a systematic way. Scientific management must be introduced and the management performance must be evaluated objectively so that a practical plan can be flexibly adjusted. It is also required to secure a long-term budget support and a stable organization and to input a concentrated budget at the proper period when there is high efficiency of eradication.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.542-549
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• 2017

To evaluate bacteriological and toxicological safety, the hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in the Kamakman Area from 2012 to 2016 were investigated. Fecal coliforms and E. coli of all 194 oyster samples tested did not exceed 230 MPN/100 g. The geometric mean of the fecal coliform analyzed with the oyster samples of harvesting period was 19.6 MPN/100 g, which was more stable than the non-harvesting period (26.5 MPN/100 g). For the toxicological evaluation of the Kamakman Area, 77 oyster samples and 350 mussel samples as an indicator were analyzed. Paralytic shellfish toxins were detected very low in the range of $40{\sim}46{\mu}g$/100 g in 13 mussel samples during late April and early June, but not in oyster samples. Diarrhetic shellfish toxin was detected in 2 of 180 samples, but it was found to be below the regulation value (0.16 mg OA equ./kg). Based on the bacteriological studies, it was confirmed that the shellfish produced in Kamakman area meets the standard of shellfish hygiene of the Food Sanitation Act and meets the Grade A of the shellfish production area of EU. As the results of the paralytic and diarrhetic shellfish toxin evaluation, it was confirmed that the Kamakman Area is also toxicologically safe for shellfish production.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.75-84
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• 2018

The inclusive playground is a playground where disabled children and non-disabled children can play together, not a playground for the disabled. It started with the change of social awareness of the citizenship rights of disabled people in the 1960s and the resulting playgrounds. Since then, inclusive playgrounds have been developed in many countries, and these are organized in the form by guidelines. In Korea, social interest in inclusive playgrounds is increasing, but there are no systematic guidelines in Korea, and the application of overseas cases or guidelines is limited. The purpose of this study is to classify the concept of inclusive playgrounds and design guidelines, that were previously presented in inclusive playground design guideline of various countries and analyze the characteristics of, design scope, and design principles, and provide a basic framework for creating guidelines. The purpose of the design guideline was to present specific numerical values to the inclusive playground design guidelines, to link with academic research and industrial products, to present pursuit values, and to expand the value of pursuing design methods. The contents were covered by scope, conceptualization, principles of design and design process, design guidelines, and checklists. Most of the guideline covers specific autonomous governments or countries that can apply the related systems or laws, but the composition of the detailed contents is different. The guiding value of inclusive playgrounds presented in each guideline is not a playground for the disabled but a playground for all, and some guidelines refer to the difficulty in playgrounds considering non-disabled children. Based on these concepts, design guidelines are presented in each guideline. Improving the accessibility in design principles is a common theme and adds to the principles of safety, independence, convenience, and playability. None of the guidelines do not provide design guidelines. Although there is a difference in the degree and method of specificity provided by each of the guidelines, the design guidelines can be generally summarized as space, copper line, and unit facilities. As mentioned in many guidelines, an inclusive playground is not only a playground for children with disabilities. Therefore, in the design guidelines, it is also important to the support play of children with disabilities and to induce inclusive play. The design guidelines presented in the guideline can be rearranged into three stages of 'supporting the play of children with disabilities', 'securing the dimensions and materials of spaces and facilities', 'adding auxiliary devices' and 'designing new facilities'. There are three design guidelines for inducing inclusive play. First, by creating various difficulty levels and intersecting spaces, children with various abilities can play with each other, and at the same time, they can interact witheach other. Second, all children can cooperate and play without distinction between children with disabilities and non-disabled children. Finally, the guardian provides the conditions for efficient support so that the disabled child can fully enjoy the inclusive playground.

• Journal of Legislation Research
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• no.44
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• pp.241-281
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• 2013

First and foremost, a discussion concerning government structure has to be done in connection with the state form and the governmental form. For practical reasons, there is a need to balance the principle of legality and its exceptions under the Government Organization Act. To ensure the flexibility of government structure with respect to the principle of legality, the National Assembly should accept the government structure requested by the newly elected government. This mitigates the rigidity of the principle of the legality within the government organizations. However, excessive changes by each government could violate the principle of legality asked by Constitution. In this sense, arbitrary modification with respect to the government structure by the newly elected government is not desirable. The long term stability of the government organization is required in any case. Secondly, general administrative agencies, other than Executive Ministries, should not be established under the direct order of the President without the control of the Prime Minister. A hierarchy of the executive branch (President->Prime Minister-> Executive Ministries) is stipulated in the Constitution. Establishing a hierarchy of President -> executive institution should be considered unconstitutional. Therefore, only the Presidential Secretariat and institutions with special functions can be established in the Presidential Office. Establishing general administrative agencies in the Presidential Office for convenience purposes is against the spirit of the current Constitution. Consequently, only the office of staffs and special agencies can be placed in the presidential office. It is against the spirit of the current Constitution to found administrative agencies under the presidential office for convenience. Thirdly, the office of the Prime Minister should be the backbone of internal affairs. In that sense, the President, as the head of state, should focus on the big picture such as the direction of the State, while the Cabinet headed by the Prime Minister should be responsible for the daily affairs of the State. The cabinet surrounding the Prime Minister must control all the ordinary affairs of the State, while the President, as the head of the State, should focus on the big picture of blueprinting the aim of the State. Lastly, the Office of the Prime Minister and Executive Ministries are the two main bodies of the executive branch. It is important to reduce the confusion caused by repeated changes in the names of Executive Ministries, to restore the traditional names and authorities of these institutions, and to rehabilitate the legitimacy of the State. For the Korean democracy to take its roots, a systematic way of stabilizing a law-governed democratic country is needed. There is also the need not only to reform security and economic agencies, but also to rationally solve the integration of technique and policy, according to the changes of time.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.46-59
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• 2023

Various Baekje ground-level building sites have been identified, in Pungnaptoseong Fortress, including Mirae Village's site E-1. However, building site E-1 is the only one with excavated roof tiles that are directly connected to the building site. As for building sites E-2, D-1, and D-2, which are comparable to site E-1, it is very possible that they had tiles on the roof based on their jeoksim (blocking facilities for roof slopes) and building structures. Also, although they are semi-underground pit structures, pit building sites A-30 and modern apartment site A-5, as well as the No.44 remains of Gyeongdang District, which is closer to a ground-level type, the buildings with tiles may have been constructed in the form of partial tile roofs rather than full-face tile roofs. Therefore, there may be several reasons behind the use of tiles on roofs in the early days, but the primary background of the building's authoritative function would have been considered first. Considering that China and Japan started using tiles on nationally important buildings such as palaces, temples, and ritual buildings, it may be presumed that Baekje began using tiles from the time it centralized power. It is believed that Baekje's early roof tile buildings evolved from rudimentary residential architecture to advanced public architecture, taking into consideration fire prevention and structural stability in large buildings. It is difficult to find similar cases in Korea with structural features such as the elevated foundations or underground stone foundations that can be found in Mirae Village building site E-1. Rather, similar architectural techniques can be found in China and Japan. In China, similar construction techniques were discovered in buildings of worship that were primarily built in the palace surroundings, such as Jangan Castle. Based on this, it appears that roof tile building sites, such as site E-1, that have been discovered have a strong correlation with the characteristics of buildings of worship, and ground type buildings, such as sites D-1 and D-2, are important facilities that are related to important public facilities such as state-run warehouses. This provides many implications regarding the early Baekje city structure.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.357-368
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• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.