• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.252-269
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• 2017

This study was carried out to examine the base temperature to flowering and the average days to flowering by accumulated hours of low temperature ($5.0^{\circ}C$) or changing temperature after bud breaking. Over-all, the prediction of flowering time in the commercial apple cultivars ('Fuji' and 'Tsugaru') and apple cultivars ('Chukwang', 'Gamhong', 'Hongan', 'Honggeum', 'Hongro', 'Hongso', 'Hwahong', 'Summer dream', 'Sunhong') bred in Korea at the Gunwi region for 4 years (from 2009 to 2012) was investigated. Also, this study estimated the flowering time when the air temperature of Gunwi region rises at $5.0^{\circ}C$ was investigated using the same data. The range of accumulated hours of low temperature (chilling requirement) was from 0 hour to 1,671 hours, and the range of high temperature (heat requirements) to flowering after low temperature treatment was from $5.0^{\circ}C$ to $29.0^{\circ}C$. The treatments of changing temperature after bud breaking were classified as constant temperature treatment (control) and $5.0{\sim}10.0^{\circ}C$ elevation or descent treatments. The results show that the average days to flowering was longer with shorter accumulated hours of low temperature, and the average days from bud breaking to flowering of 0 hour treatment was longer about 2~4 weeks than that of 1,335~1,503 hours treatments. In comparing to apple cultivars, the all cultivars were not flowered under $10.0^{\circ}C$ after bud breaking, and the cultivars with low chilling requirements needed low heat requirements for flowering. The average days to flowering of treatments that the air temperature after bud breaking was controlled about $15.0^{\circ}C$ was shorter about 1~3 weeks than that of treatments was controlled about $10.0^{\circ}C$. In the treatment of changing temperature after bud breaking, the average days from bud breaking to flowering of temperature elevation treatment was shorter than that of constant temperature treatment. By use of these results, the base temperature to flowering of main apple cultivars in Korea was seemed to $10.0^{\circ}C$, and if the air temperature of Gunwi region rises about $5.0^{\circ}C$ than that of current, the flowering time was estimated to be delayed by 1 week.

• The Korean Journal of Petroleum Geology
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• v.10 no.1_2 s.11
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• pp.23-33
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• 2004

The Lago Sofia conglomerate in southern Chile is a lenticular unit encased within mudstone-dominated, deep-sea successions (Cerro Toro Formation, upper Cretaceous), extending from north to south for more than $120{\cal}km$. The Lago Sofia conglomerate is a unique example of long, gravelly deep-sea channels, which are rare in the modern environments. In the northern part (areas of Lago Pehoe and Laguna Goic), the conglomerate unit consists of 3-5 conglomerate bodies intervened by mudstone sequences. Paleocurrent data from these bodies indicate sediment transport to the east, south, and southeart. The conglomerate bodies in the northern Part are interpreted as the tributary channels that drained down the Paleoslope and converged to form N-S-trending trunk channels. In the southern part (Lago Sofia section), the conglomerate unit comprises a thick (> 300 m) conglomerate body, which probably formed in axial trunk channels of the N-5-trending foredeep trough. The well-exposed Lago Sofia section allowed for detailed investigation of sedimentary facies and large-scale architecture of the deepsea channel conglomerate. The conglomerate in Lago Sofia section comprises stratified conglomerate, massive-to-graded conglomerate, and diamictite, which represent bedload deposition under turbidity currents, deposition by high-density turbidity currents, and muddy debris flows, respectively. Paleocurrent data suggest that the debris flows originated from the failure of nearby channel banks or slopes flanking the channel system, whereas the turbidity currents flowed parallel to the orientation of the overall channel system. Architectural elements produced by turbidity currents represent vertical stacking of gravel sheets, lateral accretion of gravel bars, migration of gravel dunes, and filling of channel thalwegs and scoured hollows, similar to those in terrestrial gravel-bed braided rivers. Observations of large-scale stratal pattern reveal that the channel bodies are offset stacked toward the east, suggestive of an eastward migration of the axial trunk channel. The eastward channel migration is probably due to tectonic tilting related to the uplift of the Andean protocordillera just west of the Lago Sofia deep-sea channel system.

• Asia pacific journal of information systems
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• v.19 no.4
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• pp.47-75
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• 2009

Recently, researches on Management Information Systems (MIS) have laid out theoretical foundation and academic paradigms by introducing diverse theories, themes, and methodologies. Especially, academic paradigms of MIS encourage a user-friendly approach by developing the technologies from the users' perspectives, which reflects the existence of strong causal relationships between information systems and user's behavior. As in other areas in social science the use of structural equation modeling (SEM) has rapidly increased in recent years especially in the MIS area. The SEM technique is important because it provides powerful ways to address key IS research problems. It also has a unique ability to simultaneously examine a series of casual relationships while analyzing multiple independent and dependent variables all at the same time. In spite of providing many benefits to the MIS researchers, there are some potential pitfalls with the analytical technique. The research objective of this study is to provide some guidelines for an appropriate use of SEM based on the assessment of current practice of using SEM in the MIS research. This study focuses on several statistical issues related to the use of SEM in the MIS research. Selected articles are assessed in three parts through the meta analysis. The first part is related to the initial specification of theoretical model of interest. The second is about data screening prior to model estimation and testing. And the last part concerns estimation and testing of theoretical models based on empirical data. This study reviewed the use of SEM in 164 empirical research articles published in four major MIS journals in Korea (APJIS, ISR, JIS and JITAM) from 1991 to 2007. APJIS, ISR, JIS and JITAM accounted for 73, 17, 58, and 16 of the total number of applications, respectively. The number of published applications has been increased over time. LISREL was the most frequently used SEM software among MIS researchers (97 studies (59.15%)), followed by AMOS (45 studies (27.44%)). In the first part, regarding issues related to the initial specification of theoretical model of interest, all of the studies have used cross-sectional data. The studies that use cross-sectional data may be able to better explain their structural model as a set of relationships. Most of SEM studies, meanwhile, have employed. confirmatory-type analysis (146 articles (89%)). For the model specification issue about model formulation, 159 (96.9%) of the studies were the full structural equation model. For only 5 researches, SEM was used for the measurement model with a set of observed variables. The average sample size for all models was 365.41, with some models retaining a sample as small as 50 and as large as 500. The second part of the issue is related to data screening prior to model estimation and testing. Data screening is important for researchers particularly in defining how they deal with missing values. Overall, discussion of data screening was reported in 118 (71.95%) of the studies while there was no study discussing evidence of multivariate normality for the models. On the third part, issues related to the estimation and testing of theoretical models on empirical data, assessing model fit is one of most important issues because it provides adequate statistical power for research models. There were multiple fit indices used in the SEM applications. The test was reported in the most of studies (146 (89%)), whereas normed-test was reported less frequently (65 studies (39.64%)). It is important that normed- of 3 or lower is required for adequate model fit. The most popular model fit indices were GFI (109 (66.46%)), AGFI (84 (51.22%)), NFI (44 (47.56%)), RMR (42 (25.61%)), CFI (59 (35.98%)), RMSEA (62 (37.80)), and NNFI (48 (29.27%)). Regarding the test of construct validity, convergent validity has been examined in 109 studies (66.46%) and discriminant validity in 98 (59.76%). 81 studies (49.39%) have reported the average variance extracted (AVE). However, there was little discussion of direct (47 (28.66%)), indirect, and total effect in the SEM models. Based on these findings, we suggest general guidelines for the use of SEM and propose some recommendations on concerning issues of latent variables models, raw data, sample size, data screening, reporting parameter estimated, model fit statistics, multivariate normality, confirmatory factor analysis, reliabilities and the decomposition of effects.

• Asia pacific journal of information systems
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• v.23 no.2
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• pp.1-20
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• 2013

Social commerce has been gaining explosive popularity, with typical examples of the model such as Groupon and Level Up. Both local business owners and consumers can benefit from this new e-commerce model. Local business owners have a chance to access potential customers and promote their products in a way that could not have otherwise been easily possible, and consumers can enjoy discounted offerings. However, questions have been increasingly raised about the value and future of the social commerce model. A recent survey shows that about a third of 324 business owners who ran a daily-deal promotion in Groupon went behind. Furthermore, more than half of the surveyed merchants did not express enthusiasm about running the promotion again. The same goes for the case in Korea, where more than half of the surveyed clients reported no significant change or even decrease in profits compared to before the use of social commerce model. Why do local business owners fail to exploit the benefits from the promotions and advertisements through the social commerce model and to make profits? Without answering this question, the model would fall under suspicion and even its sustainability might be challenged. This study aims to look into problems in the current social commerce transactions and provide implications for the social commerce model, so that the model would get a foothold for next growth. Drawing on justice theory, this study develops theoretical arguments for the effects of transaction characteristics on consumers' distributive justice and purchase intention in the social commerce. Specifically, this study focuses on two characteristics of social commerce transactions-the discount rate and the purchase rate of products-and investigates their effects on consumers' perception of distributive justice for discounted transactions in the social commerce and their perception of distributive justice for regular-priced transactions. This study also examines the relationship between distributive justice and purchase intention. We conducted an online experiment and gathered data from 115 participants to test the hypotheses. Each participant was randomly assigned to one of nine manipulated scenarios of social commerce transactions, which were generated based on the combination of three levels of purchase rate (high, medium, and low) and three levels of discount rate (high, medium, and low). We conducted MANOVA and post-hoc ANOVA to test hypotheses about the relationships between the transaction characteristics (purchase rate and discount rate) and distributive justice for each of the discounted transaction and the regular-priced transaction. We also employed a PLS analysis to test relations between distributive justice and purchase intentions. Analysis results show that a higher discount rate increases distributive justice for the discounted transaction but decreases distributive justice for the regular-priced transaction. This, coupled with the result that distributive justice for each type of transaction has a positive effect on the corresponding purchase intention, implies that a large discount in the social commerce may be helpful for attracting consumers, but harmful to the business after the promotion. However, further examination reveals curvilinear effects of the discount rate on both types of distributive justice. Specifically, we find distributive justice for the discounted transaction increases concavely as the discount rate increases while distributive justice for the regular-priced transaction decreases concavely with the dscount rate. This implies that there exists an appropriate discount rate which could promote the discounted transaction while not hurting future business of regular-priced transactions. Next, the purchase rate is found to be a critical factor that facilitates the regular-priced transaction. It has a convexly positive influence on distributive justice for the transaction. Therefore, an increase of the rate beyond some threshold would lead to a substantial level of distributive justice for the regular-priced transaction, threrby boosting future transactions. This implies that social commerce firms and sellers should employ various non-price stimuli to promote the purchase rate. Finally, we find no significant relationship between the purchase rate and distributive justice for the discounted transaction. Based on the above results, we provide several implications with future research directions.

• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.147-152
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• 2015

Nitrogen (N) loading from domestic, agricultural and industrial sources can lead to excessive growth of macrophytes or phytoplankton in aquatic environment. Many studies have used nitrogen stable isotope ratios to identify anthropogenic nitrogen in aquatic systems as a useful method for studying nitrogen cycle. In this study to evaluate the precision and accuracy of Kjeldahl processes, two reference materials (IAEA-NO-3, N-1) were analyzed repeatedly. Measured the ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ values of IAEA-NO-3 and IAEA-N-1 were $4.7{\pm}0.2$‰ and $0.4{\pm}0.3$‰, respectively, which are within recommended values of analytical uncertainties. Also, we investigated spatial patterns of ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ in effluent plumes from a waste water treatment plant in Han River, Korea. ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ values are enriched at downstream areas of water treatment plant suggesting that dissolved nitrogen in effluent plumes should be one of the main N sources in those areas. The current study clarifies the reliability of Kjeldahl analytical method and the usefulness of stable isotopic techniques to trace the contamination source of dissolved nitrogen such as nitrate and ammonia.

• Journal of Hospice and Palliative Care
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• v.17 no.1
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• pp.27-33
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• 2014

Purpose: Although vitamin D deficiency is more commonly found in cancer patient than in non-cancer patients, there have been little data regarding the prevalence of vitamin D deficiency in cancer patients at the very end of life. We examined vitamin D deficiency in terminally ill cancer patients and related factors. Methods: This study was based on a retrospective chart review of 133 patients in a hospice ward. We collected data regarding age, sex, serum 25-hydroxyvitamin D level, cancer type, physical performance, current medications and various laboratory findings. We investigated factors related to serum vitamin D levels after multivariate adjustment for potential confounders. Serum 25-hydroxyvitamin D<20 ng/mL was considered deficient and <10 ng/mL severely deficient. Results: Ninety-five percent of the patients were serum vitamin D deficient. Severe vitamin D deficiency was more common in male patients, non-lung cancer patients, $H_2$ blocker users and non-anticonvulsant users. Elevated levels of serum alanine aminotransferase (ALT) were also associated with low serum vitamin D levels. Multiple regression analysis showed that severe vitamin D deficiency was associated with male gender (aOR 3.82, 95% CI: 1.50~9.72, P=0.005), $H_2$ blocker users (aOR 3.94, 95% CI: 1.61~9.65, P=0.003) and elevated serum ALT levels (aOR 4.52, 95% CI: 1.35~15.19, P=0.015). Conclusion: Vitamin D deficiency was highly prevalent among terminally ill cancer patients. Severe vitamin D deficiency was more common in male patients, $H_2$ blocker users, and patients with elevated ALT levels.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.461-471
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• 2016

This study was conducted to establish an in vitro propagation system for sea-milkwort (Glaux maritima L.), which is an endangered coastal plant species with high horticultural value. Two phenotypes, 'Red type (RT)' and 'Pistachio type (PT)' based on the colors of stem and flower, were obtained from a personal horticulturist in 2009 and used for this study as plant materials. The stock plants showed typical morphologies in flower, capsule, and seed appearances as previously reported. Low temperature treatment at $4^{\circ}C$ for four or more weeks after in vitro sowing maximized seed germination percentage, indicating that imbibition of seed and subsequent low temperature treatment are crucial for its germination. The in vitro seedlings had phenotypic variation, falling into 'RT' and 'PT' classes like the stock plants. Although slight differences depending on genotype and medium were recognized, the fourth or fifth nodes detached from the in vitro seedlings revealed the best multiplication efficacy when estimated on the basis of total number of nodes of newly developed axillary shoots. In addition, the nodes from 'RT' and 'PT' regenerated the most shoots on medium supplemented with $0.5mg{\cdot}L^{-1}$ BA alone and $0.5mg{\cdot}L^{-1}$ BA plus $0.5mg{\cdot}L^{-1}$ IAA, respectively. The node culture-derived plantlets were well acclimatized in a culture room ex vitro and completed the pseudo-annual life cycle coincident with that in the natural salt march habitat with the current cultivation method of applying fresh water-irrigation under an inland environment. This work represents the first report of in vitro propagation of sea-milkwort. Thus, our study will contribute to exo-habitat conservation and natural habitat restoration of this endangered species in addition to development of a horticultural product.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3279-3285
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• 2014

This study aimed to understand seasonal and geographical characteristic of chlorophyll-${\alpha}$ (chl-${\alpha}$), COD (chemical oxygen demand) and Escherichia coli at Gwangyang Bay during the period from February 2010 to November 2012. The bay is divided into three different zones based on the pollutant levels and geographical characteristics. During the study periods, water temperature, salinity, Chl. ${\alpha}$, and chemical oxygen demand (COD) varied in the range of $4.68-28.63^{\circ}C$, 1.94-33.84 psu, 0.31-35.10 ${\mu}gL^{-1}$, and 0.70-13.35 $mgL^{-1}$, respectively. Total chl-a concentration were high at the zone I, which can be characterized as a semi-enclosed eutrophic area, and it were low at the zone III, which is influenced by low nutrients of surface warm water current from offshore of the bay. The high concentration of COD was observed at inner bay during the four seasons and the water quality level was kept to be bad condition during spring season at the zone II, which is influenced by Seomjin River water. The highest colony form of E. coli was recorded to be 3550 $cfuL^{-1}$ during summer at station 1 (zone I), whereas it was relatively kept low level during all seasons at the zone III. As a result, the E. coli was correlated with water temperature (r=0.31 p<0.05) and salinity (r=-0.55 p<0.05), implying that those parameters have play an important crucial role in proliferation of E. coli. Consequently, our results indicated that the E. coli can be significantly promoted within pollutant sources including the high nutrients supplied by rive discharge during spring and summer rainy seasons in semi-enclosed area of Gwangyang Bay.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.78-103
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• 2016

This research is a study on the side framework structure of the hipped and gable roof of Muryangsujeon at Buseoksa Temple. There is a record that Muryangsujeon was deconstructed and repaired in the period of Japanese Occupancy, and its authenticity has continuously been called into question because the structure of the hipped and gable side roofs, and the bonding of the rafters and eaves were not in good order and very different from those of Joseon Dynasty. Scholars date it differently. It is either dated at 13th century or 12th century. This study compares the non-planar configuration of the middle and front proportions of Muryangsujeon's hipped-and-gable-roof framework with those of the Tang(唐) and Song(宋) Dynasties in China. It concludes that the hipped-and-gable-roof framework of those architecture were built with the same technique. The style of architecture that side rafters directly touch the internal security (梁), like in Muryangsujeon, is not usual even among the hipped and garble roofs of the Tang(唐) and Song(宋) Dynasties. The technique of constructing the hipped roofs developed much further after the Tang Dynasty because they began to use garble eaves to build the side structure. The technique seems to have developed greatly by the period of Ming and Qing Dynasties. It also seems that the parallel-flat (平行輻射椽) rafter, which is the form of rafters used between the parallelrafter period and the half-flat-rafter period is very similar to the construction style of the current rafters of Muryangsujeon. However, the Muryangsujeon's eaves do not touch the corner rafter from the middle part. This seems to be a unique style, which is not common in China. In conclusion, the style of the side roof framework of Muryangsujeon at Buseoksa Temple is not of the China's southern regions, but of the northern regions of Tang(唐), Song(宋) and Liao(遼) Dynasties. And when considering the construction year and proportions of the middle front and side front on the same flat, this must be an ancient technique of the northeastern regions of Asia. Since it is likely that the structure of the side roof framework of Muryangsujeon at Buseoksa Temple has not been altered but is a unique style of hipped and gable roofs, this roof can serve as a good guide to restoring the hipped and garble roofs of the pre-Goyreo Dynasty period.

• Korean Journal of Heritage: History & Science
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• v.49 no.1
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• pp.22-43
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• 2016

State Ownership of Excavated Cultural Heritage System was originated from the legislations concerning cultural objects during the Japanese colonial period (1910~1945) and was succeeded by the present Buried Cultural Properties Act enacted in 2011. Despite the importance of the system that completes the outcomes of excavations and determines the state-owned cultural properties, the foundation of national heritage, it has been limitedly regarded as administrative area and neglected by the academic scholars or policy researchers. Recently the traditional culture has drawn increasing domestic interest and awareness that the cultural heritage contributes to building cultural identity and vitalizing tourism has led to increasing the demand of a local government's role in management of the state-designated cultural heritage and even fighting for hegemony in securing the cultural objects between the central and local governments. Despite the continuing efforts for improving the selection process of cultural heritage and its management institution, establishment of an advanced objective system has been requested. This paper is intended to suggest the policy direction through demonstrating the problem and assignment caused in the process of implementing the Buried Cultural Properties Act and reviews the State Ownership of Excavated Cultural Heritage System from the legal point of view accordingly. First, I suggest improving the selection process of the state-owned cultural properties. Even though current law states that Administrator of Cultural Heritage Administration reviews the research reports and selects the possible candidates for the state-owned cultural properties almost all the cultural objects listed on the reports are practically selected. In this regard, two possible resolutions can be made; newly establishing a separate process for selecting the state-owned cultural properties after publishing the report or adding the selection process of the state-owned cultural properties during the heritage selection meeting. Either way should contribute to strengthening the impartiality and objectivity of the policy. My second suggestion is improving the operating system of the heritage selection meeting in which the cultural properties to be listed on the reports are determined. Given the present extensive assessment criteria, there is much room for certain experts' subjective opinions. Therefore, in order to enhance the fairness and credibility of the heritage selection meeting, specifying the assessment criteria and advance review of the expert list are necessary. Third, this paper suggests increasing the local government's role in management of the state-owned cultural heritage and diversifying the heritage management institution. Development of a local self-governing system has led to the increased demand for delegating the authority of the state-owned heritage management to the local governments. Along with this, the gradual improvements of public museum management raises the need for expanding the cultural benefits through increasing the local government's role in management of the state-owned heritage. Considering the fact that overall majority of the art collections housed at national or public museums is owned by the central government, developing a variety of heritage contents and vitalizing the heritage tourism are crucial. The true meaning and value of the state-owned cultural heritage hidden at the storage of a museum can be found when they are shared together with the public.