• Tuberculosis and Respiratory Diseases
• /
• v.40 no.2
• /
• pp.177-184
• /
• 1993

Background: Accurate staging of bronchogenic carcinoma is important in determining resectability and metastasis of tumor to the subcarinal nodes is generally believed to indicate poor prognosis. The technique of Transbronchial needle aspiration (TBNA) has offered a safe & effective way to asscess mediastinal lymph node involvement in the staging of lung cancer. We performed TBNA in patients who were suspected lung cancer to evaluate the clinical usefulness of the TBNA. Method: TBNA of the subcarinal lymph node was performed at the time of initial diagnostic bronchoscopy in 60 patients with suspected lung cancer, and 42 cases of histologically proved bronchogenic cancer were analized. Results: The frequency of adequate samples by transbronchial needle aspiration (TBNA) was 81% and the positive rate of malignant cells by TBNA was 14.7%. There were no differences in positive rates by tumor cell types. In patients with thickened carina on bronchoscopy, the TBNA was positive in 33.3% as compared to 5.3% of normal carina on bronchoscopy, and the difference was statistically significant (p<0.05). In patients with enlarged subcarinal lymph node on chest CT, the positive rate of malignant cells (50.0%) was higher than that of normal sized subcarinal lymph node on chest CT (4.8%) (p<0.01). There were no specific complications in the TBNA procedure. Conclusion: TBNA is a relatively safe procedure and it offers the possibility of avoiding the cost and morbidity of surgical staging in patients especially whose carina is thickened on bronchoscopy and whose subcarinal LN was enlarged on chest CT.

• The Korean Journal of Financial Management
• /
• v.27 no.1
• /
• pp.181-208
• /
• 2010

In July 2007, Korean government has passed "The Capital Market and Financial Investment Services Act" to further develop the capital markets and the Act was to become effective in February 2009. Using a large sample of Korean firms, we have examined (i) the effect of underwriting activities on the firm value (bond spread) comparing commercial bank and investment bank, and (ii) the determinants of the firm value changes following underwriting activities of bank. To test our goal, we collected a wide range of samples of data for bond issuing activities executed by Korean firms listed on the Korea Stock Exchange (KSE) between 2000 and 2003. Our paper is distinguished from previous studies on this subject in a way that we analyzed the effect of corporate bond underwriting activities with regard to commercial banking and investment banking. Initially, we set up a hypothesis that "Certification View" and "Conflict-of-interest View" are major driving forces behind cross-firm differences in performance following bond issuance. We find that, in general, underwriting by investment bank (securities company) brings a positive effect on the firm value (spread between bench mark rate and bond issuing rate). This result indicates that firm value has been negatively affected by the bank underwriting and provides the evidence for "Conflict-of-interest View" in Korea. Our studies have also revealed that any change in firm value following bond issuance is positively related with the firm size (total asset), operating performance, liquidity (cashflow), and equity ownership by foreign investors. Overall, our results support the view that bank underwriting activities can play an important role in determining firm value and financial strategies under "The Capital Market and Financial Investment Services Act" of 2007.

• KDI Journal of Economic Policy
• /
• v.34 no.3
• /
• pp.1-29
• /
• 2012

Based on the spatial and land price data of innovation cities and their periphery areas in Korea, this study examines the degree and timing of changes in land price in relation to projects concerning innovation city. The study result confirms that the current system is inconsistent with the principle of restitution of development gain and therefore, this study attempts to seek improvement measures so that the current system can better fit the principle. The analysis reveals that most innovation cities, excluding Sinseo-dong of Daegu and Ujeong-dong of Ulsan, recorded a statistically significant increase in land prices since 2005, compared to those of their neighboring areas. It can be said that the information related to projects concerning innovation city was reflected in the land price since 2005. However, the standard land price pursuant to Article 70 of the Land Compensation Act is the officially assessed land price released on 1st of January 2007, and this official land price was actually applied to the compensation process. Therefore, estimating the compensation amount for land expropriation based on this land price will contradict the principle of restitution of development gain. In other words, despite the fact that development-related information was already reflected in land prices of innovation cities from 2005 to the end of 2006, the compensation process were carried out without institutional arrangements or efforts to exclude such reflection. To solve this problem, this study makes two suggestions. First, it is necessary to cast aside the limitations of the official land price that can be retroactively applied in accordance with Paragraph 5 of Article 70 of the Land Compensation Act, and instead apply the land price which is the most latest but deemed to have no reflection of development gains. Based on this revised standard land price, if the compensation amount is corrected by the average inflation rate and the average rate of increase in land price during the period until the time of the recognized land price, the amount would better satisfy the principle of restitution of development gain. Second, it is necessary to clearly stipulate the standards of development gains being reflected on the land price by including it in the secondary legislation. Under the current system, it is highly likely that appraiser's arbitrary interpretation on development gains is included in the process of calculating the amount of compensation for land expropriation. In this regard, it is necessary to improve the standards on determining whether development gains are reflected based on the results of this academic research and the existing guidelines for appraisal of compensation for land expropriation published by the Korea Association of Property Appraisers.

• Pediatric Infection and Vaccine
• /
• v.24 no.2
• /
• pp.95-101
• /
• 2017

Purpose: Acute bacterial gastroenteritis (ABG) can cause more severe symptoms than acute viral gastroenteritis in children. This study was aimed at determining the etiologic trends and to examine the clinical characteristics of ABG in children. Methods: We sent stool samples from the children with acute gastroenteritis who were treated at a secondary hospital located in Seoul, Korea between January 2011 and December 2014 to Seoul Metropolitan Government Research Institute of Public Health and Environment to find the causative organisms. Clinical characteristics of patient were analyzed through a medical records review. Results: Out of 664 stool samples, 183 (27.6%) yielded bacterial pathogens. Staphylococcus aureus was the most common bacterial pathogen, found in 72 cases (39.3%), even though it was only tested for since 2012. The monthly isolation rate was the highest (24.6%) in August. The isolation rate of Campylobacter spp. by patient's age group was high (16.7%) in the 12- to 18-year-age group (P=0.04). In patients with bloody stool, Campylobacter spp. was the most commonly isolated (31.0%, P=0.04). When comparing C-reactive protein, the Salmonella spp.- or Campylobacter spp.-isolated group showed higher values than the S. aureus- or pathogenic Escherichia coli-isolated group ($5.7{\pm}0.6mg/dL$ vs. $2.1{\pm}0.3mg/dL$, P<0.01). Conclusions: S. aureus, Salmonella spp., pathogenic E. coli, and Campylobacter spp. were important pathogens of ABG among children. Considering the differences in pathogens found according to age, a clinical symptom and inflammation index might be helpful in assuming the causative organism.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.5
• /
• pp.894-899
• /
• 2001

Intakes and excretions of zinc and copper were determined for 8 female adolescents (aged 16.4$\pm$0.5 y; body mass index 20.4$\pm$1.3kg/$m^2$; body fat 33.3$\pm$2.5%; bone mineral density of lumbar spine in L2-L4; 0.96$\pm$0.08g/$\textrm{cm}^2$) when they consumed diets basal and high in calcium for 6 days each. All subjects consumed a basal Ca diet containing 800 mg, Korean RDA level of the subjects, and a high Ca diet containing 1200mg, RDA plus 2 SDs of calcium intake. The diets provided 58% of energy intake as carbohydrate, 25% as fat, and 17% as protein. Food, urine and fecal samples were collected during the last 3 days of each feeding period and were assayed. Mean daily intakes on the basal and high calcium diets, respectively, were 6.57 and 6.37 mg for zinc and 910 and 812 $\mu\textrm{g}$for copper. Fecal excretion of copper and zinc in relation to intake was significantly greater on the high calcium than on the basal calcium diet. Hence, apparent absorption rate was significantly lowered from 98.7% on the basal calcium diet to 97.9% on the high calcium diet for zinc from 66.3% to 56.4% for copper, respectively. Urinary loss of copper was not detectable but that of zinc was 0.38mg on the basal diet and 0.47mg on the high calcium diet. Copper retention was 899$\pm$105$\mu\textrm{g}$/day on the basal calcium diet and 792$\pm$20.8$\mu\textrm{g}$/day on the high calcium diet, and zinc retention was 3.95$\pm$0.91mg/day and 3.11$\pm$0.89mg/day. Thus, copper and zinc retention was significantly decreased on the high calcium diet (p<0.05). Summarizing the results, apparent absorption and retention of zinc and copper were significantly decreased by calcium supplementation. Therefore, it is suggested that interactions among minerals should be considered in determining RDA.

• Journal of Korean Society of Forest Science
• /
• v.112 no.3
• /
• pp.352-362
• /
• 2023

Harvest time is one of the most important determining factors of seed quality, especially for species that produce seeds over irregular and long-term periods, such as Larix kaempferi. A cone collection plan must be established to increase seed production efficiency and stable mass production. We investigated seed qualities such as seed efficiency, germination rate, and T₅₀ (germination speed), with 7 or 8 cone collection times at a clonal seed orchard of L. kaempferi in Chungju between 2021 and 2022. A multivariate analysis was then performed for the collected data. In early August, decreases in the moisture contents and browning of cones were observed. These were followed by a decrease in germination rate, with a peak at the end of September, but no clear trend was observed. The later the cones were harvested, the better the seed vigor (T₅₀). However, the seed yield and efficiency decreased owing to increases in seed scattering and the number of insect-damaged seeds. As a result, the optimal time of seed harvest for the seed orchard was in early August. To produce uniform seedlings, insect damage must be reduced through timely control and harvest cones in early September. This shows that the degree of browning and moisture content of cones can be used as indicators of the timing of cone collection in L. kaempferi seed orchards.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.17 no.1
• /
• pp.58-72
• /
• 2009

In this study, the organic matter and biomass was characterized by using respirometry based on ASM No.2d (Activated Sludge Model No.2d). The activated sludge models are based on the ASM No.2d model, published by the IAWQ(International Association on Water Quality) task group on mathematical modeling for design and operation of biological wastewater treatment processes. For this study, OUR(Oxygen Uptake Rate) measurements were made on filtered as well as non-filtered wastewater. Also, GC-FID and LC analysis were applied for the estimation of VFAs(Volatile Fatty Acids) COD(S_A) in slowly bio-degradable soluble substrates of the ASM No.2d. Therefore, this study was intended to clearly identify slowly bio-degradable dissolved materials(S_S) and particulate materials(X_I). In addition, a method capable of determining the accurate time to measure non-biodegradable COD(S_I), by the change of transition graphs in the process of measuring microbial OUR, was presented in this study. Influent fractionation is a critical step in the model calibrations. From the results of respirometry on filtered wastewater, the fraction of fermentable and readily biodegradable organic matter(S_F), fermentation products(S_A), inert soluble matter(S_I), slowly biodegradable matter(X_S) and inert particular matter(X_I) was 33.2%, 14.1%, 6.9%, 34.7%, 5.8%, respectively. The active heterotrophic biomass fraction(X_H) was about 5.3%.

• Journal of Intelligence and Information Systems
• /
• v.26 no.2
• /
• pp.27-42
• /
• 2020

Traditional companies with offline stores were unable to secure large display space due to the problems of cost. This limitation inevitably allowed limited kinds of products to be displayed on the shelves, which resulted in consumers being deprived of the opportunity to experience various items. Taking advantage of the virtual space called the Internet, online shopping goes beyond the limits of limitations in physical space of offline shopping and is now able to display numerous products on web pages that can satisfy consumers with a variety of needs. Paradoxically, however, this can also cause consumers to experience the difficulty of comparing and evaluating too many alternatives in their purchase decision-making process. As an effort to address this side effect, various kinds of consumer's purchase decision support systems have been studied, such as keyword-based item search service and recommender systems. These systems can reduce search time for items, prevent consumer from leaving while browsing, and contribute to the seller's increased sales. Among those systems, recommender systems based on association rule mining techniques can effectively detect interrelated products from transaction data such as orders. The association between products obtained by statistical analysis provides clues to predicting how interested consumers will be in another product. However, since its algorithm is based on the number of transactions, products not sold enough so far in the early days of launch may not be included in the list of recommendations even though they are highly likely to be sold. Such missing items may not have sufficient opportunities to be exposed to consumers to record sufficient sales, and then fall into a vicious cycle of a vicious cycle of declining sales and omission in the recommendation list. This situation is an inevitable outcome in situations in which recommendations are made based on past transaction histories, rather than on determining potential future sales possibilities. This study started with the idea that reflecting the means by which this potential possibility can be identified indirectly would help to select highly recommended products. In the light of the fact that the attributes of a product affect the consumer's purchasing decisions, this study was conducted to reflect them in the recommender systems. In other words, consumers who visit a product page have shown interest in the attributes of the product and would be also interested in other products with the same attributes. On such assumption, based on these attributes, the recommender system can select recommended products that can show a higher acceptance rate. Given that a category is one of the main attributes of a product, it can be a good indicator of not only direct associations between two items but also potential associations that have yet to be revealed. Based on this idea, the study devised a recommender system that reflects not only associations between products but also categories. Through regression analysis, two kinds of associations were combined to form a model that could predict the hit rate of recommendation. To evaluate the performance of the proposed model, another regression model was also developed based only on associations between products. Comparative experiments were designed to be similar to the environment in which products are actually recommended in online shopping malls. First, the association rules for all possible combinations of antecedent and consequent items were generated from the order data. Then, hit rates for each of the associated rules were predicted from the support and confidence that are calculated by each of the models. The comparative experiments using order data collected from an online shopping mall show that the recommendation accuracy can be improved by further reflecting not only the association between products but also categories in the recommendation of related products. The proposed model showed a 2 to 3 percent improvement in hit rates compared to the existing model. From a practical point of view, it is expected to have a positive effect on improving consumers' purchasing satisfaction and increasing sellers' sales.

• Journal of Preventive Medicine and Public Health
• /
• v.31 no.4 s.63
• /
• pp.751-769
• /
• 1998

This study was conducted to assess the attitude of pregnant women toward delivery method, understanding of the reason for determining her own delivery method, participation in decision-making process and satisfaction with delivery method after labor. Study subjects were 693 pregnant women who had visited obstetric clinic for prenatal care in the last month of pregnancy in one general hospital and one obstetrics-gynecology specialty hospital in Taegu city from February 1 to March 31 in 1998. A questionnaire was administered before and after labor and a telephone interview was done one month after labor. Proportion of women who had health education and/or counselling about delivery method during prenatal care was 24.0% and this proportion was higher for women who had previous c-section(35.5%) than others. Women thought vaginal delivery is better than c-section for both maternal and baby's health regardless of previous delivery method. About 90% of primipara and multiparous women who had previous vaginal delivery wanted vaginal delivery for the index birth, while 85.6% of multiparous women who had previous c-section wanted repeat c-section. Reasons for choosing c-section in pregnant women who preferred vaginal delivery before labor were recommendation of doctors(81.9%), recommendation of husband (0.8%), agreement between doctor and pregnant woman(4.7%), and mother's demand (12.6%). Reasons for choosing vaginal delivery were mother's demand(30.6%) and no indication for c-section(67.2%). Reasons for choosing c-section in pregnant women who preferred c-section before labor were recommendation of doctors(76.2%), mother's demand(20.0%), recommendation of husband(1.3%), and agreement between doctor and pregnant woman(2.5%). Of the pregnant women who had c-section, by doctor's recommendation, the proportion of women who had heard detailed explanation about reason for c-section by doctor was 55.1%. Mother's statement about the reason for c-section was consistent with the medical record in 75.9% . However, over 5% points disparities were shown between mother's statement and medical record in cases of the repeat c-section and mother's demand. In primipara and multiparous women who had previous vaginal delivery, the delivery method for index birth had statistically significant association with the preference of delivery method before labor(p<0.05). All of the women who had previous c-section had delivered the index baby by c-section. Among mothers who had delivered the index baby vaginally, 84.9% of them were satisfied with their delivery method immediately after labor and 85.1% at 1 month after labor. However, mothers who had c-section stated that they are satisfied with c-section in 44.6% immediately after labor and 42.0% at 1 month after labor. Preferred delivery method for the next birth had statistically significant association with delivery method for the index birth both immediately after labor and in 1 month after labor. The proportion of mothers who prefer vaginal delivery for the next birth increased with the degree of satisfaction with the vaginal delivery for the index birth but the proportion of mothers who prefer c-section for the next birth was high and they did not change significantly with the degree of satisfaction with the c-section for the index birth. These results suggest that the current high technology-based, physician-centered prenatal and partritional cares need to be reoriented to the basic preventive and promotive technology-based, and mother-fetus-centered care. It is also suggested that active involvement of pregnant woman in decision-making process for the delivery method will increase the rate of vaginal birth after c-section and decrease c-section rate and improve the degree of maternal satisfaction after delivery.

• Journal of the Korea Concrete Institute
• /
• v.21 no.3
• /
• pp.245-253
• /
• 2009

The importance of chloride ions in the corrosion of steel in concrete has led to the concept for chloride threshold level (CTL). The CTL can be defined as the content of chlorides at the steel depth that is necessary to sustain local passive film breakdown and hence initiate the corrosion process. Despite the importance of the CTL, due to the uncertainty determining the actual limits in various environments for chloride-induced corrosion, conservative values such as 0.4% by weight of cement or 1.2 kg in 1 $m^3$ concrete have been used in predicting the corrosion-free service life of reinforced concrete structures. The paper studies the CTL for blended cement concrete by comparing the resistance of cementitious binder to the onset of chloride-induced corrosion of steel. Mortar specimens were cast with centrally located steel rebar of 10 mm in diameter using cementitious mortars with ordinary Portland cement (OPC) and mixed mortars replaced with 30% pulverized fuel ash (PFA), 60% ground granulated blast furnace slag (GGBS) and 10% silica fume (SF), respectively, at 0.4 of a free W/B ratio. Chlorides were admixed in mixing water ranging 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5 and 3.0% by weight of binder(Based on $C1^-$). Specimens were curd 28 days at the room temperature, wrapped in polyethylene film to avoid leaching out of chloride and hydroxyl ions. Then the corrosion rate was measured using the polarization resistance method and the order of CTL for binder was determined. Thus, CTL of OPC, 60%GGBS, 30%PFA and 10%SF were determined by 1.6%, 0.45%, 0.8% and 2.15%, respectively.