• Clean Technology
• /
• v.24 no.1
• /
• pp.41-49
• /
• 2018

Y zeolites with different extra-framework cations, such as $Na^+$, $N^+$, $Ca^{2+}$, and $Cu^{2+}$, with different charge and ionic radius have been investigated to greatly enhance a working capacity (W) of $CO_2$ adsorption at $25^{\circ}C$ and a $CO_2/CO$ selectivity factor (S). A sample of NaY with a very small amount of 0.012% $Ca^{2+}$ was fully reversible for seven times repeated $CO_2$ adsorption/desorption cycles, thereby forming no surface carbonates unlikely earlier reports. Although at pressures above 4 bar, 2.00% CaY, 1.60% CuY and 1.87% LiY all showed a $CO_2$ adsorption very similar to that measured for NaY, they gave a significant decrease in the adsorption at lower pressures, depending on the metal ion. At 0.5 ~ 2.5 bar, the extent of $CO_2$ adsorption was in the order NaY > 1.60% CuY > 2.00% CaY > 1.87% LiY. All the $Na^+-based$ metals-exchanged zeolites have a FAU (faujasite) framework and a Si/Al value near 2.6; thus, there is no discernible difference in the framework topology, framework chemical compositions, effective aperture size, and channel structure between the zeolite samples. Therefore, the distinctive behavior in the adsorption of $CO_2$ with a character as a weak Lewis acid is associated with the site basicity of the zeolites, and the interaction potentials of the cations. Different trend was shown for a CO adsorption due to weaker quadrupole interactions. Adsorption of $CO_2$ and CO on samples of CaY with 0.012 to 5.23% Ca disclosed a significant dependence on the Ca loading. The $CO_2$ adsorption increased when the cation exists up to ca. 0.05%, while it decreased at higher Ca amounts. However, values for both W and S could greatly increase as the bare zeolite is enriched by $Ca^{2+}$ ions. The 5.23% CaY had $W=2.37mmol\;g^{-1}$ and S = 4.37, and the former value was comparable to a benchmark reported in the literature.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.2
• /
• pp.397-403
• /
• 1998

Background: Little information is available concerning the value of bronchoscopy in patients with a lymphocytic exudative pleural effusion in which percutaneous pleural biopsy have been regarded as cornerstone in investigating the etiology. Recently, a few reports suggest that bronchoscopy may be more effective diagnostic method in patients with unexplained pleural effusion accompanied by hemoptysis or other roentgenographic abnormalities, such as mass, infiltrate, atelectasis. Method: Mter initial examinations of sputum and pleural fluid through thoracentesis in 112 patients(male 75 cases, female 37 cases, mean age 53.2 years) who were admitted for evaluation of the cause of pleural effusion, we performed bronchoscopy and closed pleural biology in most patients with undiagnosed lymphocytic exudate and compared the diagnostic yield of both invasive methods according to hemoptysis or other roentgenographic abnormalities, and investigated the sole diagnostic contribution of bronchoscopy. Results: Tuberculosis(57 cases, 51%) was the most common cause of pleural effusion. Percutaneous pleural biopsy showed more diagnostic yield than bronchoscopy regardless of presence or absence of other clinical or radiologic abnormalities. In 25 cases with unknown etiology after pleural biopsy, additional diagnostic yield by bronchoscopy was 36 % (4/11) in patients with associated features and only 7 % (1/14) with lone effusion, and, as the sole mean for diagnsosis in all patients with pleural effusion, was only 4.5%(5/12). Conclusion : In a region of high prevalence of tuberculosis as a cause of pleural effusion, percutaneous pleural biospy is more effective method when invasive method is required for confirmative diagnosis of unexplained lymphocytic exudative pleural effusion, and bronchoscopy is unlikely to aid in the diagnosis of lone pleural effusion.

• Journal of Energy Engineering
• /
• v.23 no.2
• /
• pp.125-148
• /
• 2014

This paper performs a historical analysis on the various factors contributing to the current carbon lock-in of Korean electricity industry by using techo-institutional complex. The possibilities of the industry's carbon lock-out toward more sustainable development are also investigated. It turns out that market, firm, consumer, and government factors are all responsible for the development of the carbon lock-in of Korean power industry; the Korean government consistently favoring large power plants based on the economy of scale; below-cost electricity tariff; inflation policy to suppress increases in power price; rapid demand growth in summer and winter seasons; rigidities of electricity tariff; and expansion of gas-fired and imported coal-fired large power plants. On the other hand, except for nuclear power generation and smart grid, environment laws and new and renewable energy laws are the other remaining factors contributing to the carbon lock-out. Considering three key points that Korea is an export-oriented economy, the generation mix is the most critical factor to decide the amounts of carbon emission in the power industry, and the share of industry and commercial power consumption is over 85%, it is unlikely that Korea will achieve the carbon lock-out of power industry in the near future. Therefore, there are needs for more integrated approaches from market, firm, consumer, and government all together in order to achieve the carbon lock-out in the electricity industry. Firstly, from the market perspective, it is necessary to persue more active new and renewable energy penetration and to guarantee consumer choices by mitigating the incumbent's monopoly power as in the OECD countries. Secondly, from the firm perspective, the promotion of distributed energy system is urgent, which includes new and renewable resources and demand resources. Thirdly, from the consumer perspective, more green choices in the power tariff and customer awareness on the carbon lock-out are needed. Lastly, the government shall urgently improve power planning frameworks to include the various externalities that were not properly reflected in the past such as environmental and social conflict costs.

• Korean Journal of Environmental Agriculture
• /
• v.21 no.1
• /
• pp.7-16
• /
• 2002

Contamination of groundwater by agrochemicals used in the regional-scale Is now a major environmental problem, and this is especially true for Cheju island where virtually all potable water is from groundwater. The objective of this study was to assess leaching potential of eight pesticides in soils of citrus orchards using groundwater ubiquity score (GUS), retardation factor (RF) and attenuation factor (AF). Considering GUS estimated in 30 citrus orchard soils, metribuzin and metolachlor were classified as leacher, alachlor in volcanic ash soils and linuron in non-volcanic soils were classified as leacher, but chlorothalonil and chlorpyrifos were classified as non-leacher. For RF values, metribuzin was classified to be mobile in soils of low organic carbon, metolachlor and alachlor were classified to be moderately immobile in most soils, but linuron, diuron, diniconazole, chlorothalonil and chlorpyrifos were all classified to be very immobile. For AF values, diniconazole, chlorothalonil, and chlorpyrifos were classified to be very unlikely leachable in all of the soils, metribuzin was classified to be likely leachable, and metolahclor, alachlor, linuron and diuron were classified to be leachable only in non-volcanic soils. Although there were some variations in the relative potential of teachability of pesticides estimated with the three different indices, the ranking was essentially determined on the base of the intrinsic properties of the chemicals and environmental properties. Among the eight pesticides, metribuzin, metolachlor, and alachlor, which have high water solubility and low $K_{oc}$ values, have a significant leaching potential especially in non-volcanic ash soils of low organic carbon. But diniconazole, chlorothalonil, and chlorpyrifos, which have low water solubility and high $K_{oc}$ values, were classified to be very immobile in all of the soils. Therefore, to lower the possibility of pesticide contamination of the groundwater in Cheju island, those pesticides which have high water solubility and low $K_{oc}$ values should be used with care in soils of low organic carbon including non-volcanic ash soils.

• The Critical Review of Religion and Culture
• /
• no.31
• /
• pp.255-287
• /
• 2017

This paper analyzes the religious circuit of suicidal concept based on verbal expression and ritual acts, which are found in the suicide discourse of Korean Catholic Church and Protestant Church. In the relationship of suicide and religion, it is easily overlooked the religious circuit and its construction that forms the concept of suicide among the religious laymen. It is assumed that the belief system of traditional religions prohibits suicide and the laymen accordingly construct a perception or concept of suicide along with this belief system. Various studies on this subject have proved it. However, in order to understand the religious way of constructing the concept of suicide on a personal level, it is necessary to pay attention to the religious environment in which the concepts and emotions of suicide circulate. The laymen do not passively and perfectly accept the finely established suicide concept provided by the doctrine or the theology. Rather, the laymen tend to collect the pieces of concept over the suicide that are drifting in the religious environment of his/her daily routine life and to make an concept of suicide in an incomplete form. We can find the unstable and imperfect traits of such a suicide concept through the experience of suicide survivors who have a religious background. For the suicide survivors with religious beliefs, they resist the formal doctrinal and theological provisions to suicide, or try to understand the notion of suicide in their own contexts. In terms of linguistic expressions and ritual acts relating to suicide, the attentions are differently directed in the public and the private domain among the religious groups. Considering on the high rates of suicide in Korean society, the Korean Catholic Churches are increasingly tolerant over the suicide and accept it in the public sphere. It is unlikely when comparing to the negative attitudes of the suicide in the past. However, such tolerance does not go beyond the doctrinal and ethical judgment that defines suicide as a serious sin. The once-committed lay believer's speech and gestures usually contain the various emotions, such as sadness, grief, anxiety, regretfulness, eagerness, and pain in the private spheres. The language and gestures with these emotions have been activated in the religious circuits of suicide, being extended to the religious apparatus for the person who died of suicide. In case of Protestantism, the institutional organizations, such as the particular denominations and the individual-churchism of the Korean Protestant Churches, and their own interpretations of the Bible have in the private sphere strongly effected on the linguistic expressions and the rituals related to the suicide. The religious-ethical judgment of the suicide is varied how the suicide is interpreted by the theologians and the pastors. And the ritual acts for healing the complex feelings and the psychological wounds of the suicide survivors are not actively explored and adopted yet. It makes harder to approach and heal the protestant followers since they emphasize the innermost belief and the salvation assurance faith.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.3
• /
• pp.562-569
• /
• 2019

Raman spectroscopy has been receiving increased attention as a standoff explosive detection technique. In addition, there is a growing need for a fast search method that can identify raman spectrum for measured chemical substances compared to known raman spectra in large database. By far the most simple and widely used method is to calculate and compare the Euclidean distance between the given spectrum and the spectra in a database. But it is non-trivial problem because of the inherent high dimensionality of the data. One of the most serious problems is the high computational complexity of searching for the closet spectra. To overcome this problem, we presented the MPS Sort with Sorted Variance+PDS method for the fast algorithm to search for the closet spectra in the last paper. the proposed algorithm uses two significant features of a vector, mean values and variance, to reject many unlikely spectra and save a great deal of computation time. In this paper, we present two new methods for the fast algorithm to search for the closet spectra. the PCA+PDS algorithm reduces the amount of computation by reducing the dimension of the data through PCA transformation with the same result as the distance calculation using the whole data. the Hierarchical Cluster Tree algorithm makes a binary hierarchical tree using PCA transformed spectra data. then it start searching from the clusters closest to the input spectrum and do not calculate many spectra that can not be candidates, which save a great deal of computation time. As the Experiment results, PCA+PDS shows about 60.06% performance improvement for the MPS Sort with Sorted Variance+PDS. also, Hierarchical Tree shows about 17.74% performance improvement for the PCA+PDS. The results obtained confirm the effectiveness of the proposed algorithm.

• Korean Journal of Heritage: History & Science
• /
• v.50 no.4
• /
• pp.168-197
• /
• 2017

This paper considers two aspects of the wooden chamber tombs with stone mound that were constructed in Wolseong North Burial Ground, in Gyeongju: tomb form and the group tomb complex. The basic unit of a wooden chamber tomb with stone mound consisted of a single round mound, covered with an additional earthen layer and surrounded by a circle of protective stones, within which a single wooden chamber was located. The form of a wooden chamber tomb with stone mound could therefore 1) be round, consisting of a single tomb unit, 2) consist of two or more attached tomb units, 3) or consist of multiple attached chambers in a single mound. The single tomb contained the burial of a single individual, and the attached tomb contained two or more individuals who were blood relations or connected by marriage. Multiple attached chambers tombs usually consisted of wooden chamber burials of the lowest rank, and have only been identified in the royal burial area of Wolseong North Burial Ground. At the Jjoksaem Area of Wolseong North Burial Ground, which is currently, under investigation, tombs have been found in small clusters along the slightly raised ground. This is likely the result of small groups of kin relations, upon selecting points along the slightly raised ground as their burial area, having constructed midsized and large single tombs and attached tombs along the axis of the slightly raised ground, which were then surrounded by smaller 'satellite' tombs. It is through this process that the tomb complex of the different groups came to be formed. The tombs of the royal burial area of Wolseong North Burial Ground, including the Daereungwon Tomb Complex, also formed group tomb complexes. Forming the centers of the group tomb complexes of the royal tomb area were huge individual round tombs where the Maripgan rulers were laid to rest or a gourd-shaped dual mound tomb, which was the final resting place of the king and his queen consort. These central tombs were surrounded by large and smaller tombs. Of the individuals that were buried in the group tomb complexes, there would have been individuals that were of equal status or social position, such as husbands and wives or blood relations, but it is unlikely that all of the buried individuals were related by blood, given the significant difference in the sizes of the tombs. It is likely that the individuals buried in the lower ranked tombs included in the group tomb complexes were 'dependents' of the deceased of the central tomb and his or her direct family who maintained a subservient relationship. Such tomb forms and group tomb complexes that can be observed amongst the wooden chamber tombs with stone mounds of Wolseong North Burial Ground provide insights into the nature of the social groups of the Silla center during the Maripgan Period. It is hoped that future studies undertaking a more detailed analysis of the data may make further contributions to unveiling the various aspects of Silla society.

• Korean Journal of Heritage: History & Science
• /
• v.50 no.1
• /
• pp.18-41
• /
• 2017

The Gangjin WolnamSaji(月南寺址) is a small site where three-story pagodas and a destroyed tombstone remained. In 1973, it was discovered that the destroyed tombstone was that of the second master of Susunsa, Hye shim(慧諶), who had a special relationship with the military regime in Goryeo, and it once again attracted attention as a result of the recent excavation of the Rooftile of Yeonhwamun(蓮花文). In particular, the Windchime excavated in 2012 is a large-sized one group with a length of 23cm, and a relatively large Sanskrit character was decorated on four sides of the body. In addition, it was also confirmed in preservation process that the word 'gaecheon(盖天)' was engraved. The Sanskrit characters(梵字) om( , oṃ), a( , a), hum( , hūṃ), brum( , bhrūṃ) were decorated on the body of the Wind-chime excavated in WolnamSaji. Om( , oṃ), a( , a), hum( , hūṃ) are known as the Sammiljineon(三密眞言) and brum( , bhrūṃ) has the meaning of having the highest honor. In addition, the Sammiljineon(三密眞言) allows us to understand the truth by responding to the principle of universe, which is the Vairocana Buddha(毘盧遮那佛), and brum( , bhrūṃ) has the meaning of unity. In the end, the meaning of the Sanskrit decorating the four sides of the Wind-chime, of WolnamSaji(月南寺址), can be interpreted as the expression of the Buddha's doctrine, or the willingness to be combined with Buddha, the highest existence in itself. It is possible that the word 'gaecheon(盖天)' carved on the body can be regarded as the name of the master craftsman related to the making of the Wind-chime, but it is unlikely that it is the name of the master craftsman, considering that it is a place where the location is not easily seen. If so, you can think of the original function that the Wind-chime has. In other words, it can be interpreted symbolically and implicitly that the wish of the sound of the airwaves symbolized by the words of the Buddha covers the sky and spreads all over the place. It is thought that the Wind-chime excavated in WolnamSaji(月南寺址) was made in the mid to late 13th century considering the comparisons with another wind-chime excavated from the temple site, the historical situation in the late Goryeo, the publication date of the scriptures(經典) of Esoteric Buddhism(密敎).

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.16 no.2
• /
• pp.51-78
• /
• 2021

Followed by 'start-up', the theme of 'scale-up' has been considered as an important agenda in both corporate and policy spheres. In particular, although it is a term commonly used in industry and policy fields, even a conceptual definition has not been achieved from the academic perspective. "Corporate Growth" in the academic aspect and "Business Growth" in the practical management field have different understandings (Achtenhagen et al., 2010). Previous research on corporate growth has not departed from Penrose(1959)'s "Firm as a bundle of resources" and "the role of managers". Based on the theory and background of economics, existing research has mainly examined factors that contribute to firms' growth and their growth patterns. Comparatively, we lack knowledge on the firms' growth with a focus on 'annual revenue growth rate'. In the early stage of the firms, they tend to exhibit a high growth rate as it started with a lower level of annual revenue. However, when the firms reach annual revenue of more than 100 billion KRW, a threshold to be classified as a 'middle-standing enterprise' by Korean standards, they are unlikely to reach a high level of revenue growth rate. In our study, we used our sample of 333 companies (6.7% out of 5,000 'fastest-growing' companies) which reached 15% of the compound annual growth rate in the last three years with more than USD 100 million. It shows that sustaining 'high-growth' above a certain firm size is difficult. The study focuses on firms with annual revenue of more than $100 billion (approximately 120 billion KRW) from the 'Inc. 2020 fast-growing companies 5,000' list. The companies have been categorized into 1) Fast-growing companies (revenue CAGR 15%~40% between 2016 and 2019), 2) Hyper-growing companies (40%~99.9%), and 3) Super-growing (100% or more) with in-depth analysis of each group's characteristics. Also, the relationship between the revenue growth rate, individual company's strategy choice (market orientation, generic strategy, growth strategy, pioneer strategy), industry/market environment, and firm age is investigated with a quantitative approach. Through conducting the study, it aims to provide a reference to the 'Hyper-Growing Model' that combines the paths and factors of growth strategies. For policymakers, our study intends to provide a reference to which factors or environmental variables should be considered for 'optimal effective combinations' to promote firms' growth.

• Journal of Food Hygiene and Safety
• /
• v.36 no.1
• /
• pp.24-33
• /
• 2021

For this study, we surveyed concentrations of 8 mycotoxins (aflatoxin B1, B2, G1, G2, ochratoxin A, fumonisin B1, B2 and zearalenone) in agricultural products used for food and medicine by liquid chromatography-tandem mass spectrometry and conducted a risk assessment. Samples were collected at the Yangnyeong Market in Seoul, Korea, between January and November 2019. Mycotoxins were extracted from these samples by adding 0.1% formic acid in 50% acetonitrile and cleaned up by using an ISOLUTE Myco cartridge. The method was validated by assessing its matrix effects, linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision using four representative matrices. Matrix-matched standard calibration was used for quantification and the calibration curves of all analytes showed good linearity (r2>0.9999). LODs and LOQs were in the range of 0.02-0.11 ㎍/kg and 0.06-0.26 ㎍/kg, respectively. Sample recoveries were from 81.2 to 118.7% and relative standard deviations lower than 8.90%. The method developed in this study was applied to analyze a total of 187 samples, and aflatoxin B1 was detected at the range of 1.18-7.29 ㎍/kg (below the maximum allowable limit set by the Ministry of Food and Drug Safety, MFDS), whereas aflatoxin B2, G1 and G2 were not detected. Mycotoxins that are not regulated presently in Korea were also detected: fumonisin (0.84-14.25 ㎍/kg), ochratoxin A (0.76-17.42 ㎍/kg), and zearalenone (1.73-15.96 ㎍/kg). Risk assessment was evaluated by using estimated daily intake (EDI) and specific guideline values. These results indicate that the overall exposure level of Koreans to mycotoxins due to the intake of agricultural products used for food and medicine is unlikely to be a major risk factor for their health.