• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1245-1251
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• 2011

As a result of the growing livestock industry, varieties of organic solid and waste biomass are be generated in swine breeding and slaughtering stages. Anaerobic digestion is a promising alternative for the treatment of livestock waste biomass, as well as for the material recovery and energy production. Objectives of this study were to analyze the biochemical methane potential of swine waste biomasses that were generated from swine pen and slaughterhouse and to investigate the material recovery and methane yield per head. As pig waste biomass, swine slurry, blood, intestine residue, and digestive tract content were collected for investigation from pig farmhouse and slaughterhouse. The $B_{th}$ (Theoretical methane potential) and $B_0$ (Biochemical methane potential) of swine slurry generating in swine breeding stage were 0.525 and $0.360Nm^3\;kg^{-1}-VS_{added}$, the ratio of degradation ($B_0/B_{th}$) was 68.6%. $B_{th}$ of blood, intestine residue, and digestive tract content were 0.539, 0.664, and $0.517Nm^3\;kg^{-1}-VS_{added}$, and $B_0$ were 0.405, 0.213, and $0.240Nm^3\;kg^{-1}-VS_{added}$, respectively. And the ratio of degradation showed 75.1, 32.1, and 46.4% in blood, intestine residue, and digestive tract content. Material yield of swine waste biomass was calculated as TS 73.79, VS 46.75, TN 5.58, $P_2O_5$ 1.94, and $K_2O$ $2.91kg\;head^{-1}$. And methane yield was $16.58Nm^3\;head^{-1}$. In the aspect that slaughterhouse is a large point source of waste biomass, while swine farmhouse is non-point source, the feasibility of an anaerobic digestion using the slaughtering waste biomass need to be assessed in the economical aspect between the waste treatment cost and the profitable effect by methane production.

• Clean Technology
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• v.27 no.4
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• pp.367-371
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• 2021

The oxy-combustion system is one of the carbon recovery and storage technologies (CCS: Carbon capture & storage) that performs coal combustion using pure oxygen and recirculated flue gas. This is a technology that facilitates storage of carbon dioxide by generating an exhaust gas consisting of only carbon dioxide without a process of separating carbon dioxide and nitrogen when coal is burned using pure oxygen and recirculated flue gas mixture instead of a conventional air combustion system that produces carbon dioxide and nitrogen mixed exhaust gas. In this study, the characteristics of generated NO and SO₂ as atmospheric pollutants during oxy-combustion were examined using O₂/CO₂ mixed simulation gas. The reaction temperature was varied from 900 ℃ to 1200 ℃ and oxygen partial pressure was varied from 30% to 50%. The results showed that NO and SO₂ concentrations in flue gas increased as the oxygen concentration and the reaction temperature in the furnace increased. The partial pressure of CO₂ in flue gas also increased as the oxygen concentration and the reaction temperature in the furnace increased. As a results of comparing NO production of 30% O₂/CO₂ oxy-combustion with air combustion, NO in flue gas increased with reaction temperature in both experiments and NO of oxy-combustion was 40 ~ 80 ppm lower than that of air combustion.

• Publications of The Korean Astronomical Society
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• v.36 no.3
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• pp.65-78
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• 2021

Jagyeokru, an automatic striking water clock described in the Sejong Sillok (Veritable Records of King Sejong) is essentially composed of a water quantity control device and a time-signal device, with the former controlling the amount or the flow rate of water and the latter automatically informing the time based on the former. What connects these two parts is a signal generating device or a power transmission device called the 'Jujeon' system, which includes a copper rod on the float and ball-racked scheduled plates. The copper products excavated under Gongpyeong-dong in Seoul include a lot of broken plate pieces and cylinder-like devices. If some plate pieces are put together, a large square plate with circular holes located in a zigzag can be completed, and at the upper right of it is carved 'the first scheduled plate (一箭).' Cylinder-like devices generally 3.8 cm in diameter are able to release a ball, and have a ginkgo leaf-like screen fixed on the inner axis and a bird-shaped hook of which the leg fixes another axis and the beak attaches to the leaf side. The lateral view of this cylinder-like device appears like a trapezoid and mounts an iron ball. The function of releasing a ball agrees with the description of Borugak Pavilion, where Jagyeokru was installed, written by Kim Don (1385 ~ 1440). The other accounts of Borugak Pavilion's and Heumgyeonggak Pavilion's water clocks describe these copper plates and ball releasing devices as the 'Jujeon' system. According to the description of Borugak Pavilion, a square wooden column has copper plates on the left and right sides the same height as the column, and the left copper plate has 12 drilled holes to keep the time of a 12 double-hours. Meanwhile, the right plate has 25 holes which represent seasonal night 5-hours (Kyeong) and their 5-subhours (Jeom), not 12 hours. There are 11 scheduled plates for seasonal night 5-hours made with copper, which are made to be attached or detached as the season. In accordance with Nujutongui (manual for the operation of the yardstick for the clepsydra), the first scheduled plate for the night is used from the winter solstice (冬至) to 2 days after Daehan (大寒), and from 4 days before Soseol (小雪) to a day before the winter solstice. Besides the first scheduled plate, we confirm discovering a third scheduled plate and a sixth scheduled plate among the excavated copper materials based on the spacing between holes. On the other hand, the width of the scheduled plate is different for these artifacts, measured as 144 mm compared to the description of the Borugak Pavilion, which is recorded as 51 mm. From this perspective, they may be the scheduled plates for the Heumgyeonggak Ongru made in 1438 (or 1554) or for the new Fortress Pavilion installed in Changdeokgung palace completed in 1536 (the 31^st year of the reign of King Jungjong) in the early Joseon dynasty. This study presents the concept of the scheduled plates described in the literature, including their new operating mechanism. In addition, a detailed model of 11 scheduled plates is designed from the records and on the excavated relics. It is expected that this study will aid in efforts to restore and reconstruct the automatic water clocks of the early Joseon dynasty.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1329-1340
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• 2021

The intertidal zone, which is a transitional zone between the ocean and the land, requires continuous monitoring as various changes occur rapidly due to artificial activity and natural disturbance. Monitoring of coastal topography changes using remote sensing method is evaluated to be effective in overcoming the limitations of intertidal zone accessibility and observing long-term topographic changes in intertidal zone. Most of the existing coastal topographic monitoring studies using remote sensing were conducted through high spatial resolution images such as Landsat and Sentinel. This study extracted the waterline using the NDWI from the GOCI-II (Geostationary Ocean Color Satellite-II) data, identified the changes in the intertidal area in Gyeonggi Bay according to various tidal heights, and examined the utility of DEM generation and topography altitude change observation over a short period of time. GOCI-II (249 scenes), Sentinel-2A/B (39 scenes), Landsat 8 OLI (7 scenes) images were obtained around Gyeonggi Bay from October 8, 2020 to August 16, 2021. If generating intertidal area DEM, Sentinel and Landsat images required at least 3 months to 1 year of data collection, but the GOCI-II satellite was able to generate intertidal area DEM in Gyeonggi Bay using only one day of data according to tidal heights, and the topography altitude was also observed through exposure frequency. When observing coastal topography changes using the GOCI-II satellite, it would be a good idea to detect topography changes early through a short cycle and to accurately interpolate and utilize insufficient spatial resolutions using multi-remote sensing data of high resolution. Based on the above results, it is expected that it will be possible to quickly provide information necessary for the latest topographic map and coastal management of the Korean Peninsula by expanding the research area and developing technologies that can be automatically analyzed and detected.

• The Journal of the Petrological Society of Korea
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• v.28 no.2
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• pp.111-128
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• 2019

Ulleung Island is the top of an intraplate alkalic volcano rising 3200 m from sea floor in the East Sea (or Sea of Japan). The emergent 984.6 m consist of eruptive products of basaltic, trachytic and phonolitic magmas, which are divided into Dodong Basaltic Rocks, and Ulleung, Seonginbong and Nari groups. The Maljandeung Tuff in the Nari Group consists of thick pyroclastic sequences which are subdivided into 4 members (N-5, U-4, 3, 2), generating from explosive eruptions during past 18.8~5.6 ka B.P. From chemical data, the Member N-5, phonolitic in composition, is considerably enriched in incompatible elements and REE patterns with significant negative Eu anomalies. The members 4, 3 and 2 are phonolitic to tephriphonolitic in composition, and their REE patterns do not have significant Eu anomalies. In variation trend diagrams, many elements show abrupt compositional gaps between members, and gradual upward-mafic variations from phonolite to tephriphonolite within each member. It suggests a downward-mafic zonation that were evolved into phonolitic zone in the lower part to tephriphonolitic zone in upper part of magma chamber. It is supposed that the chemical stratification generated from multiple mechanisms of thermal gravidiffusion, crystal fractionation, and gradual melting and sequential emplacement. The stratified magmas were explosively erupted to generate a small caldera during short period (11 ka B.P.). Especially both members (U-3, 2) were accumulated by gradually erupting from the upper phonoltic zone to the lower tephriphonoltic zone of the stratified chamber in 8.4 ka B.P. and 5.6 ka B.P. time, respectively.

• Journal of Intelligence and Information Systems
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• v.25 no.2
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• pp.99-122
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• 2019

According to the recent IDC (International Data Corporation) report, as from 2025, the total volume of data is estimated to reach ten times higher than that of 2016, corresponding to 163 zettabytes. then the main body of generating information is moving more toward corporations than consumers. So-called "the wave of Big-data" is arriving, and the following aftermath affects entire industries and firms, respectively and collectively. Therefore, effective management of vast amounts of data is more important than ever in terms of the firm. However, there have been no previous studies that measure the effects of big data investment, even though there are number of previous studies that quantitatively the effects of IT investment. Therefore, we quantitatively analyze the Big-data investment effects, which assists firm's investment decision making. This study applied the Event Study Methodology, which is based on the efficient market hypothesis as the theoretical basis, to measure the effect of the big data investment of firms on the response of market investors. In addition, five sub-variables were set to analyze this effect in more depth: the contents are firm size classification, industry classification (finance and ICT), investment completion classification, and vendor existence classification. To measure the impact of Big data investment announcements, Data from 91 announcements from 2010 to 2017 were used as data, and the effect of investment was more empirically observed by observing changes in corporate value immediately after the disclosure. This study collected data on Big Data Investment related to Naver 's' News' category, the largest portal site in Korea. In addition, when selecting the target companies, we extracted the disclosures of listed companies in the KOSPI and KOSDAQ market. During the collection process, the search keywords were searched through the keywords 'Big data construction', 'Big data introduction', 'Big data investment', 'Big data order', and 'Big data development'. The results of the empirically proved analysis are as follows. First, we found that the market value of 91 publicly listed firms, who announced Big-data investment, increased by 0.92%. In particular, we can see that the market value of finance firms, non-ICT firms, small-cap firms are significantly increased. This result can be interpreted as the market investors perceive positively the big data investment of the enterprise, allowing market investors to better understand the company's big data investment. Second, statistical demonstration that the market value of financial firms and non - ICT firms increases after Big data investment announcement is proved statistically. Third, this study measured the effect of big data investment by dividing by company size and classified it into the top 30% and the bottom 30% of company size standard (market capitalization) without measuring the median value. To maximize the difference. The analysis showed that the investment effect of small sample companies was greater, and the difference between the two groups was also clear. Fourth, one of the most significant features of this study is that the Big Data Investment announcements are classified and structured according to vendor status. We have shown that the investment effect of a group with vendor involvement (with or without a vendor) is very large, indicating that market investors are very positive about the involvement of big data specialist vendors. Lastly but not least, it is also interesting that market investors are evaluating investment more positively at the time of the Big data Investment announcement, which is scheduled to be built rather than completed. Applying this to the industry, it would be effective for a company to make a disclosure when it decided to invest in big data in terms of increasing the market value. Our study has an academic implication, as prior research looked for the impact of Big-data investment has been nonexistent. This study also has a practical implication in that it can be a practical reference material for business decision makers considering big data investment.

• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.4-31
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• 2018

The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.

• (The) Korean Journal of Educational Psychology
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• v.31 no.4
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• pp.767-794
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• 2017

Creativity is a social byproduct formed in a specific sociocultural context. Although creativity differs according to the level of culture ranging from supranational, national, professional to organizational levels, research studies documented in literature have mainly dealt with creativity in the (super)national level. For example, differences in personal creativity in the East and the West led by collectivism and individualism, respectively have been dominating in the studies about cultural differences in creativity. Consequently, the domain specificity of creativity and the effects of a more micro level of culture, such as domains, occupations, and organizations, on creative outcomes have been dismissed. Understanding the characteristics of domains, and sociocultural and environmental factors leading to creative products is worth investigating considering that the conception of creativity today highly relies on the nature of domains valued in a certain sociocultural environment. This study reviewed a wide range of literature regarding creativity and sociocultural and environmental factors in order to explore how culture and/or cultural factors inspired creative thinking and generating ideas for creative performance and products. Cultural factors were identified either as a value or a practice (custom) and examined on the supernational, national, professional, and organizational levels. For supernational and national cultures, issues on individualism, collectivism, artistic social atmosphere, and multi-cultural experiences were discussed, while the professional and organizational cultures delved topics on the domain of architecture in which both originality and functionality are greatly valued for creativity. The authors concluded that the impact of culture on creative thinking and idea generation varied according to the levels of culture although issues on multifactorial aspects of culture, differences between personal and collective creativity, and the identification of culture either as a value or a practice (custom) should be discussed further for future studies.

• Korean Journal of Poultry Science
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• v.46 no.1
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• pp.17-24
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• 2019

Chickens have been considered as well-defined animal bioreactor. The optimized ovalbumin promoter is essential for recombinant protein production in transgenic chicken. Here we try to compare the activity and identify the effect of estrogen on ovalbumin promoter according to each promoter length with estrogen response element (ERE) existence. We cloned two (2.8 and 5.5 kb) ovalbumin promoters that the 5.5 kb contained the ERE but the 2.8 kb did not, and these two promoters were cloned to pGL4.11 vector. Additionally, we constructed another pGL4.11 vector containing of the 4.4 kb (with ERE) ovalbumin promoter deleted with 1 kb between ERE region and the 2.8 kb promoter. For reporter assay, HeLa, MES-SA, LMH/2A, and cEF cells were transfected with all the pGL4.11 vectors. The comparative analysis showed that the mutated 4.4 kb promoter has more potent activity than the 2.8 and 5.5 kb promoters in HeLa, MES-SA, and LMH/2A cells. However, there is no significant difference in cEFs. Also, these cells transfected with the mutated 4.4 kb promoter were treated with the $17{\beta}$-estradiol (0~3,000 nM) and HeLa, MES-SA, and LMH/2A cells showed estrogen responsibilities, but cEFs did not. Besides, the mutated 4.4 kb promoter has still higher activity than the 2.8 and 5.5 kb promoter, and there is no transcriptional induction effect in 2.8 kb promoter at 500 nM estrogen that is blood concentration of laying hens. Hence our study strongly suggested that the mutated 4.4 kb promoter is considered as one of the most efficient length for generating transgenic chicken.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.834-846
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• 2017

An increase in the number of retiring experienced pilots as well as drastic graying of new pilots will raise the problems on deepening imbalance of supply and demand of pilots over the next 7 years, which could entail fatal problems for the safety of harbour pilotage. In this study, the improvement plan of legal system to ease imbalance between supply and demand of pilots and help secure more experienced pilots has been proposed. A current state survey and analysis, statistical analysis, questionnaire survey on foreign countries, in-depth consultation with experts, etc., were all carried out to support this research. The conclusions of this study are, firstly, to propose an amendment that the minimum requirement of 5 years of seagoing service as a master to sit for the pilot exam should be relaxed to 2 years(which must include at least 1 year of master's seagoing service within the most recent 5 years) but the minimum requirement of 1 year of pilotage service should be reinforced to 1 year and 6 months to obtain a higher class of pilot certificate. Secondly, it is proposed that an amendment offering an additional 1 point per year over the minimum period of 2 years of seagoing service as a master should be added, with a maximum of 10 points in order to rationalize the additional incentive point system. In order to secure experienced pilots and resolve the legal conflict between the certificate revalidation system and the retirement system, it is also proposed that an amendment be passed revoking the retirement system and limiting the validity of any new certificates only to 68 years of age when issuing or revalidating a certificate, if an applicant is over a certain age. Promotional work, such as collecting opinions from interested parties and generating positive public awareness, should be carried out in the future. It will also be necessary to conduct a study on the training pilot exam system.