• Korean Journal of Environment and Ecology
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• v.36 no.1
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• pp.1-29
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• 2022

This study surveyed the Mt. Teomo·Hyeolgu and surrounding areas in Ganghwa Island, located in Ganghwa-gun, Incheon, to identify vascular flora and alien plants to be used as basic data for systematic management of the remarkable plants and biodiversity conservation. The survey was carried out 13 times from March 2019 to October 2020. The identified vascular flora of Mt.Teomo·Hyeolgu was 101 families, 321 genera, 517 species, 13 subspecies, 38 varieties, 5 forms, and 573 taxa. They accounted for about 12.35% of a total of 4,641 taxa of vascular plants in Korea. The identified Northern lineage plants, endemic plants, and rare plants on the Korean Peninsula as designated by IUCN were 68 taxa, 10 taxa, and 9 taxa, respectively. 69 taxa were classified as floristic target species. Three taxa, including Maui sedge [Carex thunbergii var. appendiculata (Trautv. & C.A.Mey.) Ohwi] were identified s Class IV and 14 taxa, including Violet Stanavoi clematis (Clematis fusca var. violacea Maxim.) were identified as Class III. The naturalized plants that appeared in the study site were 63 taxa, including daisy fleabane [Erigeron annuus(L.) Pers.], common ragweed [Ambrosia artemisiifoliaL.] and Canadian fleabane [Conyza canadensis(L.) Cronquist]. The above three species were found to have spread throughout Ganghwa Island and surrounding areas such as Seokmo Island, Gyodong Island, and Gimpo city. As introduced disturbing plants like prickly lettuce [Lactuca scariola L.], bur cucumber [Sicyos angulatus L.] and field dock [Rumex acetosella L.] have been newly reported in the Mt. Teomo·Hyeolgu area, mid- to long-term conservation measures should be established for native plants, such as remarkable plants, and also management measures like physical removal should be prepared at an early stage.

• Asia Marketing Journal
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• v.11 no.3
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• pp.31-56
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• 2009

As the competition intensifies and the market matures, marketers are more and more concerned with the relationship marketing. Many of the previous researches have pointed out that not all of the consumers are relationship-oriented. But none of the previous research has systematically investigated this issue. This research investigated the relationship among the three concepts: consumers' intrinsic characteristics, perceived importance of relational benefits, and relationship building intention with the salesperson. In this research the perceived importance of relational benefits is treated as mediating variable in the relationship between consumers' intrinsic characteristics and relationship building intention with the salesperson. The conceptual model in this study can be depicted as follows. From the consumers' perspective relational benefits can be defined as "the additional benefits consumers can receive in addition to core services through the long-term relationship with the service provider." And in this study two kinds of relational benefits are adopted by reviewing the previous research: confidence benefits and social benefits. Relational benefit received from the salesperson is very important to predict consumers' relationship building intention with the salesperson. The more relational benefits consumer wants from the salesperson, the more relationship building intention he/she has. From this point two hypotheses are derived as follows. Hypothesis 1: As the perceived importance of confidence benefit from the salesperson increases, the relationship building intention with the salesperson increases. Hypothesis 2: As the perceived importance of social benefit from the salesperson increases, the relationship building intention with the salesperson increases. In this study four individual characteristics(risk taking tendency, variety-seeking tendency, product knowledge, trust orientation) are hypothesized to influence the perceived importance of confidence benefits from the salesperson. And three individual characteristics(interpersonal orientation, price consciousness, trust orientation) are hypothesized to influence the perceived importance of social benefits from the salesperson. These 7 hypotheses are as follows. Hypothesis 3: As the risk taking tendency increases, the perceived importance of confidence benefits from the salesperson decreases. Hypothesis 4: As the variety-seeking tendency increases, the perceived importance of confidence benefits from the salesperson decreases. Hypothesis 5: As the product knowledge increases, the perceived importance of confidence benefits from the salesperson decreases. Hypothesis 6: As the trust orientation increases, the perceived importance of confidence benefits from the salesperson increases. Hypothesis 7: As the interpersonal orientation increases, the perceived importance of social benefits from the salesperson increases. Hypothesis 8: As the price consciousness increases, the perceived importance of social benefits from the salesperson decreases. Hypothesis 9: As the trust orientation increases, the perceived importance of social benefits from the salesperson increases. The whole model in this study can be depicted as follows: Data were collected from the 396 consumers who actually trade stocks through the salesperson and were analyzed using structural equation model. The analysis results show that consumers' perceived importance of relational benefits(confidence benefit and social benefit) play the roles of mediating variables in the causal relationship between consumers' inherent characteristics and their relationship building intention with the salesperson. As for the individual characteristics, the influences of variety-seeking tendency, trust orientation, and price consciousness are statistically significant. It was found that variety-seeking tendency has a significant negative effect on the perceived importance of confidence benefit, and that trust orientation has a significant positive effect on the perceived importance of both of confidence and social benefit. Finally it was also found that, on the contrary to the influence direction suggested in the hypothesis, price consciousness has a significant positive effect on the perceived importance of social benefit.

• Korean small business review
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• v.39 no.1
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• pp.1-39
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• 2017

The first generation of the business that had been founded in 1960~1970s faces the situation to consider the succession of the family business developed by devotion of their whole lives in the critical timing to the next generation. In the process of selecting the party of family business succession, it is required to consider a variety of succession types including smooth transfer to the other family member or the employee of the company, selling the company, or hiring external specialist. Foreign countries acknowledge the importance of the succession in the family owned company to perform multiple studies on the influential factors to the succession, distinction, and types of family business succession; and they utilize the results for the related policy development and the support of family owned business succession. However, few studies have been conducted on the succession of the domestic family owned business and majority of them are related to the types of succession. Considering its share and influential power in the domestic economy, it is necessary to develop the guideline and the policies to solve many issues on the succession of the family owned business by systemic studies. Hence, the impact of the main characteristics in the family owned business on the types of its succession was analyzed in this study focusing on five domains of Socioemtional Wealth (SEW) in view of Behavioral Agency Theory by Gomez-Mejia et al. (2007) using the data from 540 family owned small-to-medium sized businesses so as to analyze the issues on their business succession. Upon the empirical analysis results, it was confirmed that they were influenced to the selection of succession type by family succession > internal employee succession > external succession, for the variables of social contribution which were non-financial characteristics, internal employee succession > family succession > external succession for the intellectual properties, and family succession > external succession for the management participation of the family. The distinction of social contribution were influenced the most to the selection of the succession types. Financial factors, business performance, and R&D investment variables were not significantly influenced to their selection of the succession types. In case of simultaneous management, the family succession rate was high and it showed the control effect to strengthen selecting family owned business with R&D investment, social contribution, and company history variables. The behavioral agency theory used in this study was confirmed with high explanation power on the family owned business succession. The family owned business showed the tendency to maintain SEW, and non-financial factors such as accumulated know-how and social contribution based on the long term history were significantly affected to the succession in the small-to-medium sized family owned businesses, unlike general large sized listed companies. The results of this study are expected to be helpful practically for the succession of the family owned business and to suggest the guideline for the development of governmental policy.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.327-336
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• 2023

This study aimed to propose an effective method for surveying wild birds by comparing the results of bioacoustic detection with those obtained through a field survey. The study sites were located at Dongbaek-dongsan and a 1100-altitude wetland in Jeju-do, South Korea. The bioacoustic detection was conducted over the course of 12 months in 2020. For the bioacoustic detection, a Song-meter SM4 device was installed at each study site, recording bird songs in 1-min per hour, .wav, and 44,100 Hz format. The findings of the field survey were taken from the 「Long-term trends of Bird Community at Dongbaekdongsan and 1100-Highland Wetland of Jeju Island, South Korea.」 by Banjade et al. (2019). The results of this study are as follows. First, the avifauna identified using bioacoustic detection comprised 29 families and 46 species in Dongbaek-dongsan, and 16 families and 25 species in the 1100-altitude wetland. Second, based on the song frequency, the dominant species in Dongbaek-dongsan were Hypsipetes amaurotis (Brown-eared Bulbul, 33.62%), Horornis diphone (Japanese Bush Warbler, 12.13%), and Zosterops japonicus (Warbling White-eye, 9.77%). In the 1100-altitude wetland the dominant species were Corvus macrorhynchos (Large-billed Crow, 27.34%), H. diphone (19.43%), and H. amaurotis (16.56%). Third, in the field survey conducted at Dongbaek-dongsan, the number of detected bird species was 39 in 2009, 51 in 2012, 35 in 2015, and 45 in 2018, while the bioacoustic detection identified 46 species. In the field survey conducted in the 1100-altitude wetland, the number of detected bird species was 37 in 2009, 42 in 2012, 34 in 2015, and 38 in 2018, while the bioacoustics detection identified 25 species. Overall, 43.6% of the 78 species detected in the field survey in Dongbaek-dongsan (34 species) were identified using bioacoustic detection, and 38.3% of the 47 species detected in the field survey in the 1100-altitude wetland (18 species) were identified using bioacoustic detection. Fourth, the bioacoustic detection identified 9 families and 12 species of birds in Dongbaek-dongsan, and 3 families and 7 species of birds in the 1100-altitude wetland. No results from field survey were available for these species. The identified birds were predominantly nocturnal, including Otus sunia (Oriental Scops Owl) and Ninox japonica (Northern Boobook), passage migrants, including Larvivora cyane (Siberian Blue Robin), L. sibilans (Rufous-tailed Robin), and winter visitors with a relatively small number of visiting individuals, such as Bombycilla garrulus (Bohemian Waxwing) and Loxia curvirostra (Red Crossbill). Fifth, the birds detected in the field survey but not through bioacoustic detection included 18 families and 48 species in Dongbaek-dongsan and 14 families and 27 species in the 1100-altitude wetland; the most representative families were Ardeidae, Accipitridae, and Muscicapidae. This study is significant as it provides essential data supporting the possibility of an effective survey combining bioacoustic detection with field studies, given the increasing use of bioacoustic devices in ornithological studies in South Korea.

• Korean Association of Arts Management
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• no.50
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• pp.101-146
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• 2019

After the enactment of the Local Culture Promotion Act in 2014, the government has been continuously trying to find the direction of the local culture that reflects the local life and conforms to the local people's emotions. In response to these efforts, the Organizing Committee for the C Region Biennale has uniquely formed the Biennale Artistic Director as a local artist who includes the historical, ecological and emotional characteristics of the C region. Therefore, I sought to explore the perception of the identity and role of the local cultural arts director through the narratives of the research participants who were appointed as the local residents of the C region and the director of the Craft Biennale. For the study, six local cultural arts directors were selected as research participants, and their identity as a local cultural arts director and its role were explored, focusing on their narratives. In this process, various types of data such as photographs, documents, in - depth interviews, and conference materials were collected and narrative was analyzed based on deterministic events. The results of the investigation are as follows. The idea of the identity of the local cultural arts directors was found to be in three directions. First, it is the view that the symbolic role of the artistic supervisory system of the 10 persons guarantees the identity. Second, the identity of local cultural arts directors was recognized as a role to find ways to be localized by developing and debating cultural and artistic discourses in various regions. Third, the participants had a concern and affection for local cultural arts, not one-time but continuous, and recognized it as their identity. The directors who participated in the interviews showed that the discourse of cultural arts in various regions were developed and discussed, and they wanted to find ways to be localized. The roles of local cultural arts directors recognized by research participants in connection with their identity are as follows. First, it should be the subject of systematic and long-term planning that can close the year and connect with the art events of the following year. Second, it should play a role of academic / research that can derive the identity of social and cultural ecological analysis connected with the area. Third, local arts professionals are required to act as cultural brokers, ie local culture professionals, who can create a venue for international cultural exchanges. Research on the form of local government supervision as a mediator of local cultural arts is to find out the origin of the identity of local artists and to establish a methodology for the direction of culture and art as a subject of local people. In addition, there is a need for continued interest and research in providing a reflection on the communication and meaning of the desirable local culture, and suggesting the system for cultivating local cultural arts intermediaries.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.4
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• pp.403-414
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• 2023

Backgrounds/Aims: Pancreatoduodenectomy (PD) is recommended in fit patients with a carcinoma (PDAC) of the pancreatic head, and a delayed resection may affect survival. This study aimed to correlate the time from staging to PD with long-term survival, and study the impact of preoperative investigations (if any) on the timing of surgery. Methods: Data were extracted from the Recurrence After Whipple's (RAW) study, a multicentre retrospective study of PD outcomes. Only PDAC patients who underwent an upfront resection were included. Patients who received neoadjuvant chemo-/radiotherapy were excluded. Group A (PD within 28 days of most recent preoperative computed tomography [CT]) was compared to group B (> 28 days). Results: A total of 595 patents were included. Compared to group A (median CT-PD time: 12.5 days, interquartile range: 6-21), group B (49 days, 39-64.5) had similar one-year survival (73% vs. 75%, p = 0.6), five-year survival (23% vs. 21%, p = 0.6) and median time-to-death (17 vs. 18 months, p = 0.8). Staging laparoscopy (43 vs. 29.5 days, p = 0.009) and preoperative biliary stenting (39 vs. 20 days, p < 0.001) were associated with a delay to PD, but magnetic resonance imaging (32 vs. 32 days, p = 0.5), positron emission tomography (40 vs. 31 days, p > 0.99) and endoscopic ultrasonography (28 vs. 32 days, p > 0.99) were not. Conclusions: Although a treatment delay may give rise to patient anxiety, our findings would suggest this does not correlate with worse survival. A delay may be necessary to obtain further information and minimize the number of PD patients diagnosed with early disease recurrence.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.4
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• pp.18-31
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• 2024

This study examines the inscription trends and characteristics of 121 cultural landscapes inscribed on the UNESCO World Heritage List to gain a comprehensive understanding of their inherent values and attributes. By employing a dual methodology involving descriptive statistical analysis and in-depth case studies, this research investigates the geographical distribution, temporal inscription patterns, selection criteria, and typologies of these landscapes. The data for this study were collected from official documents and databases available on the UNESCO World Heritage Center website, ensuring the reliability and authenticity of the information. The analysis reveals that cultural landscapes are predominantly concentrated in Europe and Asia, with a steady increase in inscriptions since 1992. These landscapes are primarily recognized for their uniqueness in reflecting human-nature interactions, as well as the importance of traditional culture and land-use practices, resulting in their inscription mainly under criteria (iv), (iii), (v), and (ii). Furthermore, cultural landscapes can be broadly categorized into three types: designed landscapes, organically evolved landscapes, and associative landscapes. Among these, organically evolved landscapes, formed through long-term interactions between human activities such as agriculture and industry and the natural environment, constitute a significant proportion. These findings suggest that UNESCO World Heritage cultural landscapes possess a complex value system encompassing nature and culture, tangible and intangible elements, and material and non-material aspects. This necessitates a fundamental shift in the perception and preservation approaches to cultural heritage, requiring an integrated approach that emphasizes the overall context rather than individual elements and focuses on the dynamic process of landscape evolution itself. Moreover, cultural landscapes have the potential to contribute to sustainable development models by fostering regional identity, strengthening community resilience, and promoting sustainable economic growth. Therefore, the preservation and management of cultural landscapes require a perspective that holistically views the dynamic evolution process of the landscape and a governance system based on the active participation of local communities and stakeholders. This study contributes to enhancing the in-depth understanding of the characteristics and values of cultural landscapes and provides a foundation for the selection and management of future cultural landscape heritage sites.

• Journal of Global Scholars of Marketing Science
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• v.19 no.4
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• pp.32-43
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• 2009

Trust has been studied extensively in psychology, economics, and sociology, and its importance has been emphasized not only in marketing, but also in business disciplines in general. Unlike past relationships between suppliers and buyers, which take considerable advantage of private networks and may involve unethical business practices, partnerships between suppliers and buyers are at the core of success for industrial marketing amid intense global competition in the 21st century. A high level of mutual cooperation occurs through an exchange relationship based on trust, which brings long-term benefits, competitive enhancements, and transaction cost reductions, among other benefits, for both buyers and suppliers. In spite of the important role of trust, existing studies in buy-supply situations overlook the role of trust and do not systematically analyze the effect of trust on relational performance. Consequently, an in-depth study that determines the relation of trust to the relational performance between buyers and suppliers of business services is absolutely needed. Business services in this study, which include those supporting the manufacturing industry, are drawing attention as the economic growth engine for the next generation. The Korean government has selected business services as a strategic area for the development of manufacturing sectors. Since the demands for opening business services markets are becoming fiercer, the competitiveness of the business service industry must be promoted now more than ever. The purpose of this study is to investigate the effect of the mutual trust between buyers and suppliers on relational performance. Specifically, this study proposed a theoretical model of trust-relational performance in the transactions of business services and empirically tested the hypotheses delineated from the framework. The study suggests strategic implications based on research findings. Empirical data were collected via multiple methods, including via telephone, mail, and in-person interviews. Sample companies were knowledge-based companies supplying and purchasing business services in Korea. The present study collected data on a dyadic basis. Each pair of sample companies includes a buying company and its corresponding supplying company. Mutual trust was traced for each pair of companies. This study proposes a model of trust-relational performance of buying-supplying for business services. The model consists of trust and its antecedents and consequences. The trust of buyers is classified into trust toward the supplying company and trust toward salespersons. Viewing trust both at the individual level and the organizational level is based on the research of Doney and Cannon (1997). Normally, buyers are the subject of trust, but this study supposes that suppliers are the subjects. Hence, it uniquely focused on the bilateral perspective of perceived risk. In other words, suppliers, like buyers, are the subject of trust since transactions are normally bilateral. From this point of view, suppliers' trust in buyers is as important as buyers' trust in suppliers. The suppliers' trust is influenced by the extent to which it trusts the buying companies and the buyers. This classification of trust using an individual level and an organization level is based on the suggestion of Doney and Cannon (1997). Trust affects the process of supplier selection, which works in a bilateral manner. Suppliers are actively involved in the supplier selection process, working very closely with buyers. In addition, the process is affected by the extent to which each party trusts its partners. The selection process consists of certain steps: recognition, information search, supplier selection, and performance evaluation. As a result of the process, both buyers and suppliers evaluate the performance and take corrective actions on the basis of such outcomes as tangible, intangible, and/or side effects. The measurement of trust used for the present study was developed on the basis of the studies of Mayer, Davis and Schoorman (1995) and Mayer and Davis (1999). Based on their recommendations, the three dimensions of trust used for the study include ability, benevolence, and integrity. The original questions were adjusted to the context of the transactions of business services. For example, a question such as "He/she has professional capabilities" has been changed to "The salesperson showed professional capabilities while we talked about our products." The measurement used for this study differs from those used in previous studies (Rotter 1967; Sullivan and Peterson 1982; Dwyer and Oh 1987). The measurements of the antecedents and consequences of trust used for this study were developed on the basis of Doney and Cannon (1997). The original questions were adjusted to the context of transactions in business services. In particular, questions were developed for both buyers and suppliers to address the following factors: reputation (integrity, customer care, good-will), market standing (company size, market share, positioning in the industry), willingness to customize (product, process, delivery), information sharing (proprietary information, private information), willingness to maintain relationships, perceived professionalism, authority empowerment, buyer-seller similarity, and contact frequency. As a consequential variable of trust, relational performance was measured. Relational performance is classified into tangible effects, intangible effects, and side effects. Tangible effects include financial performance; intangible effects include improvements in relations, network developing, and internal employee satisfaction; side effects include those not included either in the tangible or intangible effects. Three hundred fifty pairs of companies were contacted, and one hundred five pairs of companies responded. After deleting five company pairs because of incomplete responses, one hundred five pairs of companies were used for data analysis. The response ratio of the companies used for data analysis is 30% (105/350), which is above the average response ratio in industrial marketing research. As for the characteristics of the respondent companies, the majority of the companies operate service businesses for both buyers (85.4%) and suppliers (81.8%). The majority of buyers (76%) deal with consumer goods, while the majority of suppliers (70%) deal with industrial goods. This may imply that buyers process the incoming material, parts, and components to produce the finished consumer goods. As indicated by their report of the length of acquaintance with their partners, suppliers appear to have longer business relationships than do buyers. Hypothesis 1 tested the effects of buyer-supplier characteristics on trust. The salesperson's professionalism (t=2.070, p<0.05) and authority empowerment (t=2.328, p<0.05) positively affected buyers' trust toward suppliers. On the other hand, authority empowerment (t=2.192, p<0.05) positively affected supplier trust toward buyers. For both buyers and suppliers, the degree of authority empowerment plays a crucial role in the maintenance of their trust in each other. Hypothesis 2 tested the effects of buyerseller relational characteristics on trust. Buyers tend to trust suppliers, as suppliers make every effort to contact buyers (t=2.212, p<0.05). This tendency has also been shown to be much stronger for suppliers (t=2.591, p<0.01). On the other hand suppliers trust buyers because suppliers perceive buyers as being similar to themselves (t=2.702, p<0.01). This finding confirmed the results of Crosby, Evans, and Cowles (1990), which reported that suppliers and buyers build relationships through regular meetings, either for business or personal matters. Hypothesis 3 tested the effects of trust on perceived risk. It has been found that for both suppliers and buyers the lower is the trust, the higher is the perceived risk (t=-6.621, p<0.01 for buyers; t=-2.437, p<0.05). Interestingly, this tendency has been shown to be much stronger for buyers than for suppliers. One possible explanation for this higher level of perceived risk is that buyers normally perceive higher risks than do suppliers in transactions involving business services. For this reason, it is necessary for suppliers to implement risk reduction strategies for buyers. Hypothesis 4 tested the effects of trust on information searching. It has been found that for both suppliers and buyers, contrary to expectation, trust depends on their partner's reputation (t=2.929, p<0.01 for buyers; t=2.711, p<0.05 for suppliers). This finding shows that suppliers with good reputations tend to be trusted. Prior experience did not show any significant relationship with trust for either buyers or suppliers. Hypothesis 5 tested the effects of trust on supplier/buyer selection. Unlike buyers, suppliers tend to trust buyers when they think that previous transactions with buyers were important (t=2.913 p<0.01). However, this study did not show any significant relationship between source loyalty and the trust of buyers in suppliers. Hypothesis 6 tested the effects of trust on relational performances. For buyers and suppliers, financial performance reportedly improved when they trusted their partners (t=2.301, p<0.05 for buyers; t=3.692, p<0.01 for suppliers). It is interesting that this tendency was much stronger for suppliers than it was for buyers. Similarly, competitiveness was reported to improve when buyers and suppliers trusted their partners (t=3.563, p<0.01 for buyers; t=3.042, p<0.01 for suppliers). For suppliers, efficiency and productivity were reportedly improved when they trusted buyers (t=2.673, p<0.01). Other performance indices showed insignificant relationships with trust. The findings of this study have some strategic implications. First and most importantly, trust-based transactions are beneficial for both suppliers and buyers. As verified in the study, financial performance can be improved through efforts to build and maintain mutual trust. Similarly, competitiveness can be increased through the same kinds of effort. Second, trust-based transactions can facilitate the reduction of perceived risks inherent in the purchasing situation. This finding has implications for both suppliers and buyers. It is generally believed that buyers perceive higher risks in a highly involved purchasing situation. To reduce risks, previous studies have recommended that suppliers devise risk-reducing tactics. Moving beyond these recommendations, the present study uniquely focused on the bilateral perspective of perceived risk. In other words, suppliers are also susceptible to perceived risks, especially when they supply services that require very technical and sophisticated manipulations and maintenance. Consequently, buyers and suppliers must solve problems together in close collaboration. Hence, mutual trust plays a crucial role in the problem-solving process. Third, as found in this study, the more authority a salesperson has, the more he or she can be trusted. This finding is very important with regard to tactics. Building trust is a long-term assignment; however, when mutual trust has not been developed, suppliers can overcome the problems they encounter by empowering a salesperson with the authority to make certain decisions. This finding applies to suppliers as well.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.600-612
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• 1996

Background : Recent studies deported that untreated patients with obstructive sleep apnea syndrome had high long-term mortality rates, and cardiovascular complications of these patients clad a major effect on mortality. Several data indicates that obstructive sheep apnea syndrome contributes to the development of diurnal systemic hypertension. But the pathophysiological mechanism of the development of systemic hypertension in these patients is still uncertain. This study was performed to evaluate the possible role of sympathetic nervous system activity for the development of systemic hypertension in patients with obstructive sleep apnea syndrome. Method : 35 patients with obstructive sleep apnea syndrome(OSAS) and 13 Control subjects(control) were included in this study. 21 patients of OSAS were normotensives(OSAS-NBP), and 14 patients of OSAS were hypertensives(OSAS-HBP). Full night polysomnography was undertaken to all subjects. We measured plasma norepinephrine(NE) and epinephrine(EP) concentrations during waking and sleep, using high performance liquid chromatography, in all patients and control subjects. Results : In OSAS, OSAS-NBP and control, plasma NE and EP concentrations during sleep were lowed than during waking(p<0.01). But, in OSAS-HBP, these was no difference between during waking and sleep. Plasma NE concentrations during sleep of OSAS, OSAS-NBP and OSAS-HBP were higher than Control(p<0.05). In OSAS-HBP, daytime systolic blood pressure correlated with plasma NE concentration during sleep(r=0.7415, p<0.01), arid correlated inversely with mean arterial oxygen saturation(r=-0.6465, p<0.05) or arterial oxygen saturation nadir(r=-0.6) 14, p<0.05) during sleep. Conclusion : The sympathetic activity during sleep of obstructive sleep apnea syndrome patients was higher than control subjects. In obstructive sleep apnea syndrome patients with systemic hypertension, there was no diurnal variation of sympathetic activity, and there was correlation between daytime systolic blood pressure and sympathetic activity during sleep. These data suggests that chronic hyperactivity of sympathetic nervous system may contribute to the development of diurnal systemic hypertension in patients with obstructive sleep apnea syndrome.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.40-46
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• 2013

The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.