• Design & Manufacturing
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• v.17 no.4
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• pp.72-78
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• 2023

Injection molding is a process widely used in various industries because of its high production speed and ease of mass production during the plastic manufacturing process, and the product is molded by injecting molten plastic into the mold at high speed and pressure. Since process conditions such as resin and mold temperature mutually affect the process and the quality of the molded product, it is difficult to accurately predict quality through mathematical or statistical methods. Recently, studies to predict the quality of injection molded products by applying artificial neural networks, which are known to be very useful for analyzing nonlinear types of problems, are actively underway. In this study, structural optimization of neural networks was conducted by applying multi-task learning techniques according to the characteristics of the input and output parameters of the artificial neural network. A structure reflecting the characteristics of each process step was applied to the input parameters, and a structure reflecting the quality characteristics of the injection molded part was applied to the output parameters using multi-tasking learning. Building an artificial neural network to predict the three qualities (mass, diameter, height) of injection-molded product under six process conditions (melt temperature, mold temperature, injection speed, packing pressure, pacing time, cooling time) and comparing its performance with the existing neural network, we observed enhancements in prediction accuracy for mass, diameter, and height by approximately 69.38%, 24.87%, and 39.87%, respectively.

• Journal of the Korean Dietetic Association
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• v.30 no.1
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• pp.11-28
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• 2024

This study aimed to establish the optimal amount of thickening agent for the appropriate viscosity in soups and beverages, which are part of the dysphagia diet. The soups were bean sprout soup and soybean paste soup; the beverages were orange juice, regular milk, and low-fat milk; the thickening agent was one type of xanthan gum product. After adding the thickening agents (from 1 g to 5 g per 200 mL of the test food), syringe tests were conducted over time (5, 10 and 15 minutes) to verify the effects of the amount of thickening agent added per sample and the time between addition and achieving the resulting viscosity, and to establish the optimal addition conditions to reach IDDSI levels 1, 2, and 3 of the dysphagia diet. Water (based on 200 mL) was used as the standard control. These results provide a useful basis for customized diets based on the patient's dysphagia severity. On the other hand, this study is limited by including only liquid foods in the dysphagia diet and one type of xanthan gum-based thickening agent. Therefore, it is necessary to conduct continuous research, based on the study results, to modify the viscosity of the dysphagia diet using various thickening agents and foods and prevent nutritional deficiencies by managing the diet according to the patient's swallowing ability.

• Clinical Endoscopy
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• v.57 no.2
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• pp.141-157
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• 2024

Antithrombotic agents, including antiplatelet agents and anticoagulants, are widely used in Korea because of the increasing incidence of cardiocerebrovascular disease and the aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. The clinical practice guidelines for this issue, developed by the Korean Society of Gastrointestinal Endoscopy, were published in 2020. However, new evidence on the use of dual antiplatelet therapy and direct anticoagulant management has emerged, and revised guidelines have been issued in the United States and Europe. Accordingly, the previous guidelines were revised. Cardiologists were part of the group that developed the guideline, and the recommendations went through a consensus-reaching process among international experts. This guideline presents 14 recommendations made based on the Grading of Recommendations, Assessment, Development, and Evaluation methodology and was reviewed by multidisciplinary experts. These guidelines provide useful information that can assist endoscopists in the management of patients receiving antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

• The korean journal of orthodontics
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• v.32 no.4 s.93
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• pp.235-240
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• 2002

Surgical-orthodontic treatment is an increasingly more common dental procedure whose unique psycho-social or psychological feature has not been fairly quantified objectively. Since the treatment of a surgical-orthodontic (or orthodontic) patient is part science and part art, a subjective recognition of a patient about his or her own treatment may be more important than technical success during and after treatment. Therefore, the knowledge of the patient's underlying psychological status could be useful in the prediction of patient's response to surgical-orthodontic (or orthodontic) treatment. The purpose of this study was to investigate and evaluate the psychological difference between conventional orthodontic patient and surgical-orthodontic patient by using locus of control (LOC) examination. Locus of control scale has been proven to be extremely useful in the prediction of a variety of human behaviors. Two types of locus of control data (I-score, Internal locus of control score : I-score, External locus of control score) were obtained for 42 surgical-orthodontic patients and randomly selected 42 conventional orthodontic patients (as a control group) matched for age and gender. No statistically significant difference was observed in the scale of internal and external locus of control between the groups of surgical-orthodontic patients and conventional orthodontic patients. However, in the group of surgical-orthodontic patients, males showed lower E-score (external locus of control score, higher internal locus of control tendency) than females. The results of this study suggested that the psychological background of surgical-orthodontic patients, in contrast with that of cosmetic surgery patients, has a similar disposition with that of orthodontic patients.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.517-525
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• 1992

Background: Since its development by Saiki et al, polymerase chain reaction (PCR) has been very useful in various fields of molecular biology. PCR can be used for the detection of a very small amount of microbial agent, and is especially useful in those patients who are difficult to diagnose microbiologically or serologically. Mycobacterium tuberculosis is a very slowly growing organism and AFB staining frequently shows false negative results, and therefore PCR would be a very rapid, easy, and sensitive diagnostic method for the diagnosis of Mycobacterium tuberculosis. Method: To compare PCR with conventional methods in diagnosing Mycobacterium tuberculosis in sputum, we used sputa of patients who visited or were admitted to Seoul National University Hospital. The amplification targets were 383 base pair DNA, a part of 2520 base pair DNA encoding 65 kD Mycobacterium tuberculosis specific protein (the primers are TB-1, -2), and 123 base pair DNA, a part of IS6110 fragment, which multiple copies are known to exsist PCR one genome (the primers are Sal I-1, -2). We also requested AFB staing and culture to the lab of Seoul National University Hospital with the same sample and compared the results. Results: 1) Using TB-1, -2 primers, PCR was positive in 73.1% (19/26) of culture positive sputa, in 12.5% (1/8) of culture negative. but clinically diagnosed tuberculous sputa, and was negative in all sputa of patients who were clinically diagnosed as non-tuberculous etiology. 2) Using Sal I-I, -2 primers, PCR was positive in 94.1% (32/34) of culture positive sputa, in 23.1% (6/26) of culture negative, but clinically diagnosed tuberculous sputa, and was negative in 87.5% (14/16) of sputa from patients who were clinically diagnosed as non-tuberculous etiology. Conclusion: PCR could be a very rapid, sensitive and specific method for the diagnosis of Mycobacterium tuberculosis in sputa, and further studies should be followed for the development of easier method.

• Asia pacific journal of information systems
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• v.22 no.1
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• pp.29-52
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• 2012

Consumers differ in the way they make a purchase. An audio mania would willingly make a bold, yet serious, decision to buy a top-of-the-line home theater system, while he is not interested in replacing his two-decade-old shabby car. On the contrary, an automobile enthusiast wouldn't mind spending forty thousand dollars to buy a new Jaguar convertible, yet cares little about his junky component system. It is product involvement that helps us explain such differences among individuals in the purchase style. Product involvement refers to the extent to which a product is perceived to be important to a consumer (Zaichkowsky, 2001). Product involvement is an important factor that strongly influences consumer's purchase decision-making process, and thus has been of prime interest to consumer behavior researchers. Furthermore, researchers found that involvement is closely related to perceived risk (Dholakia, 2001). While abundant research exists addressing how product involvement relates to overall perceived risk, little attention has been paid to the relationship between involvement and different types of perceived risk in an electronic commerce setting. Given that perceived risk can be a substantial barrier to the online purchase (Jarvenpaa, 2000), research addressing such an issue will offer useful implications on what specific types of perceived risk an online firm should focus on mitigating if it is to increase sales to a fullest potential. Meanwhile, past research has focused on such consumer responses as information search and dissemination as a consequence of involvement, neglecting other behavioral responses like online merchant selection. For one example, will a consumer seriously considering the purchase of a pricey Guzzi bag perceive a great degree of risk associated with online buying and therefore choose to buy it from a digital storefront rather than from an online marketplace to mitigate risk? Will a consumer require greater trust on the part of the online merchant when the perceived risk of online buying is rather high? We intend to find answers to these research questions through an empirical study. This paper explores the impact of enduring product involvement and perceived risks on required trust level, and further on online merchant choice. For the purpose of the research, five types or components of perceived risk are taken into consideration, including financial, performance, delivery, psychological, and social risks. A research model has been built around the constructs under consideration, and 12 hypotheses have been developed based on the research model to examine the relationships between enduring involvement and five components of perceived risk, between five components of perceived risk and required trust level, between enduring involvement and required trust level, and finally between required trust level and preference toward an e-tailer. To attain our research objectives, we conducted an empirical analysis consisting of two phases of data collection: a pilot test and main survey. The pilot test was conducted using 25 college students to ensure that the questionnaire items are clear and straightforward. Then the main survey was conducted using 295 college students at a major university for nine days between December 13, 2010 and December 21, 2010. The measures employed to test the model included eight constructs: (1) enduring involvement, (2) financial risk, (3) performance risk, (4) delivery risk, (5) psychological risk, (6) social risk, (7) required trust level, (8) preference toward an e-tailer. The statistical package, SPSS 17.0, was used to test the internal consistency among the items within the individual measures. Based on the Cronbach's ${\alpha}$ coefficients of the individual measure, the reliability of all the variables is supported. Meanwhile, the Amos 18.0 package was employed to perform a confirmatory factor analysis designed to assess the unidimensionality of the measures. The goodness of fit for the measurement model was satisfied. Unidimensionality was tested using convergent, discriminant, and nomological validity. The statistical evidences proved that the three types of validity were all satisfied. Now the structured equation modeling technique was used to analyze the individual paths along the relationships among the research constructs. The results indicated that enduring involvement has significant positive relationships with all the five components of perceived risk, while only performance risk is significantly related to trust level required by consumers for purchase. It can be inferred from the findings that product performance problems are mostly likely to occur when a merchant behaves in an opportunistic manner. Positive relationships were also found between involvement and required trust level and between required trust level and online merchant choice. Enduring involvement is concerned with the pleasure a consumer derives from a product class and/or with the desire for knowledge for the product class, and thus is likely to motivate the consumer to look for ways of mitigating perceived risk by requiring a higher level of trust on the part of the online merchant. Likewise, a consumer requiring a high level of trust on the merchant will choose a digital storefront rather than an e-marketplace, since a digital storefront is believed to be trustworthier than an e-marketplace, as it fulfills orders by itself rather than acting as an intermediary. The findings of the present research provide both academic and practical implications. The first academic implication is that enduring product involvement is a strong motivator of consumer responses, especially the selection of a merchant, in the context of electronic shopping. Secondly, academicians are advised to pay attention to the finding that an individual component or type of perceived risk can be used as an important research construct, since it would allow one to pinpoint the specific types of risk that are influenced by antecedents or that influence consequents. Meanwhile, our research provides implications useful for online merchants (both online storefronts and e-marketplaces). Merchants may develop strategies to attract consumers by managing perceived performance risk involved in purchase decisions, since it was found to have significant positive relationship with the level of trust required by a consumer on the part of the merchant. One way to manage performance risk would be to thoroughly examine the product before shipping to ensure that it has no deficiencies or flaws. Secondly, digital storefronts are advised to focus on symbolic goods (e.g., cars, cell phones, fashion outfits, and handbags) in which consumers are relatively more involved than others, whereas e- marketplaces should put their emphasis on non-symbolic goods (e.g., drinks, books, MP3 players, and bike accessories).

• Tuberculosis and Respiratory Diseases
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• v.49 no.5
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• pp.546-557
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• 2000

Background : Oligonucleotide chip technology has proven to be a very useful tool in the rapid diagnosis of infectious disease. Rifampin resistance is considered as a useful marker of multidrug-resistance in tuberculosis. Mutations in the rpoB gene coding $\beta$ subunit of RNA polymerase represent the main mechanism of rifampin resistance. The purpose of this study was to develop a diagnosis kit using oligonucleotide chip for the rapid and accurate detection of rifampin-resistance in Mycobacterium tuberculosis. Method : The sequence specific probes for mutations in the rpoB gene were designed and spotted onto the glass slide, oligonucleotide chip. 38 clinical isolates of Mycobacterium were tested. A part of rpoB was amplified, labelled, and hybridized on the oligonucleotide chip with probes. Results were analyzed with a laser scanner. Direct sequencing was done to verify the results. Result : The low-density oligonucleotide chip design어 to determine the specific mutations in the rpoB gene of M. tuberculosis accurately detected rifampin resistance associated with mutations in 28 clinical isolates. Mutations at codons 531, 526, and 513 were confirmed by direct sequencing analysis. Conclusion : Mutant detection using oligonucleotide chip technology is a reliable and useful diagnostic tool for the detection of multidrug-resistance in M. tuberculosis.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.60-66
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• 2015

This study was conducted to determine the effects of seed storage method ($-20^{\circ}C$, $2^{\circ}C$ dry, $2^{\circ}C$ wet 30 days, $2^{\circ}C$ wet 60 days, stratification and room temperature) and shading treatment(control, 50%, 80%) on seed germination, seedling growth of endangered species, Iris dichotoma and Iris setosa. As a result, seed germination rate of I. dichotoma was the highest at 75% when seed were stored at $2^{\circ}C$ wet 60 days and then sown under non-shading condition. The seed of I. dichotoma belong to intermediate seed. Seed germination rate of I. setosa was the highest at 95% when seed were stored at $2^{\circ}C$ wet 60 days and then sown under 80% shading condition. The seed of I. setosa belong to recalcitrant seed. Seedlings of I. dichotoma and I. setosa showed not only the best seedling quality but also seedling vigor index in seed stored at $2^{\circ}C$ wet 60 days under non-shading condition, with the growth characteristics of plant height (6.4, 7.2 cm), number of leaves (3, 4), leaf width (4.6, 3.2 mm), leaf length (5.7, 6.8 cm), fresh weight (aerial/root part; 144/260, 97/153 mg), dry weight (aerial/root; 31/20, 17/17 mg) and seedling vigor index and modified seedling vigor index (13,895/9,479, 13,256/8,668). In this research, I. dichotoma and I. setosa seed were stored at $2^{\circ}C$ wet 60 days, and then sown in non-shading condition, seed germination rate was more than 75%, 90%, respectively, and production of superior quality seedlings.

• Ocean and Polar Research
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• v.25 no.2
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• pp.183-200
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• 2003

In order to assess the ecological changes induced by organic pollutants of the Shihwa Lake, BPI (Benthic Pollution Index) based on the benthic faunal community was employed. It was modified from Infaunal Trophic Index (ITI), and recommended as a pollution detecting method for the environmental assessment. The BPI values were calculated from the benthos data, which were collected for three terms: in 1980, before the Shihwa Lake was built up; in 1994-1997, which the Shihwa Lake was completely isolated from the outer seawater; in 1997-1999, after inflow of the outer seawater. Since the Shihwa Dike was constructed in February 1994, the pollution intensity of the lake had been increased from the narrow and inner part of the former Gyeonggi Bay and spread fast along the coast line of the Shihwa Lake. Then, in 1996 it showed the very high BPI levels all around the Lake. This serious polluted condition had been lasted till 1997, when the inflow of the seawater was begun. In 1998, from the nearest part of the Shihwa Gate, the BPI levels gradually became low in most area of the Lake, except its inner and narrow part. These greatly lowered BPI levels mean that the seawater inflow could be assumed to affect positively in the lake. Furthermore, BPI gave the same results from the other environmental assessment based on the abundance and the species richness of macrobenthic community. It shows that BPI could be useful as an effective method to assess the marine environment and evaluate the status of environmental conditions.

• The Journal of the Petrological Society of Korea
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• v.14 no.2 s.40
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• pp.116-126
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• 2005

The Precambrian quartzite and calc-schist layers experienced multi-1310ing events are distributed along the two kinds of U-shaped 1310 (Fold I and II) with $N10^{\circ}E-directed$ fo1d axis in Wollong-myeon, Gwangtan-myeon, Jori-myeon of Paju city, the northeastern part of Gyeonggido. Occurrence of 10 layers of quartzite and 4 layers of calc-schist is not clear whether quartzite and schist layers were deposited sequentially each other or one to two layers of quartzite and schist were distributed repeatedly by isoclinal folding and thrusting, because of lack of sedimentary structures. In this paper, we tried to clarify the correlative relationship among the quartzite beds which are distributed along the U-shaped folds using geochemical tools such as rare earth element (REE) patterns and Nd isotope ratio. Quartzites have characteristics of LREE-flattened, HREE- slightly depleted patterns. They also show Ce negative anomaly whereas there are no Eu anomalies. As a result, quartzite beds occurred along the bilateral sides of fold axis show very similar REE patterns from outer side to inner side of 1314. The Nd model age of quartzite layers shows a trend that the inner part of fold is younger than the outer part of it. Such geochemical characteristics suggest that bilateral quartzite beds occurred along the fold axis were derived from the cogenetic source materials. The REE patterns and trace element geochemistry of mica schist intercalated within quartzite indicate that the quartzite and mica schist may be derived from different source materials. Our results suggest that REE and Nd isotope geochemistries may be very useful in clarifying the relationship of sedimentary deposits which do not show stratigraphical and structural connections in the field.