• Journal of Digital Convergence
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• v.10 no.10
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• pp.483-490
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• 2012

In parallel with advancement of the industrial society and accompanied quality-of-life improvement, jewelry is now rather viewed as one of common accessories used in daily life, than as a luxurious item as treated before change of perception about it in the past, attracting thus gradually multiplying demand for it. Thanks to rapid spread of multi media like the Internet, an increasing number of people have come to develop great liking for exceptional design and unique format of jewelry products. Following drain of their reserves, natural gems are unlikely to meet the demand for them fully in the future. As a consequence, it seems essential to rely on synthetic, artificial, imitation jewelry or organic substances and quasi-mineral in amorphous structure for substitute jewelry. Since synthetic jewelry has such a great potential as substitute jewelry, it is expected to maximize added value to jewelry if and when accompanied with development of creative design and upgrading of processing technology for jewelry, in addition to various types of synthetic jewelry and glass that have been already put in use as substitute substances. Synthetic jewelry is thus believed to be able to greatly contribute to progress of the jewelry industry. In many countries of the world, jewelry and gem industry has been regarded as one of promising sectors vital in enriching the national wealth. In this context, the Korean Ministry of Finance and Economy announced in July 2007 "an activating policy for the jewelry and gem industry, declaring to cultivate and grow it to be new engine for the nation's growth". The present paper thus aims to conduct a study exclusively on cutting design of synthetic jewelry as a part of measures to activate the jewelry industry in Korea. Efforts are made to develop designs for jewelry that are unique and different from the conventional stereotyped form of polishing and are added with color, pattern and fashionable cutting. Priority is given in this regard to designing jewelry that may attract general public and may be shared by public beyond the limit of conventional design for jewelry and producing products that stand in contrast with other products. By upgrading the quality of jewelry design, competitiveness of the jewelry industry may be ensured and the creative area of jewelry design may be expanded by far.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.5
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• pp.25-33
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• 2011

This work proposes a skinny-type 10b 50MS/s 0.13um CMOS three-step pipeline ADC for CIS applications. Analog circuits for CIS applications commonly employ a high supply voltage to acquire a sufficiently acceptable dynamic range, while digital circuits use a low supply voltage to minimize power consumption. The proposed ADC converts analog signals in a wide-swing range to low voltage-based digital data using both of the two supply voltages. An op-amp sharing technique employed in residue amplifiers properly controls currents depending on the amplification mode of each pipeline stage, optimizes the performance of op-amps, and improves the power efficiency. In three FLASH ADCs, the number of input stages are reduced in half by the interpolation technique while each comparator consists of only a latch with low kick-back noise based on pull-down switches to separate the input nodes and output nodes. Reference circuits achieve a required settling time only with on-chip low-power drivers and digital correction logic has two kinds of level shifter depending on signal-voltage levels to be processed. The prototype ADC in a 0.13um CMOS to support 0.35um thick-gate-oxide transistors demonstrates the measured DNL and INL within 0.42LSB and 1.19LSB, respectively. The ADC shows a maximum SNDR of 55.4dB and a maximum SFDR of 68.7dB at 50MS/s, respectively. The ADC with an active die area of 0.53$mm^2$ consumes 15.6mW at 50MS/s with an analog voltage of 2.0V and two digital voltages of 2.8V ($=D_H$) and 1.2V ($=D_L$).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.971-978
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• 2017

Danggui leaf (Angelica acutiloba Kitagawa) has numerous dietary fiber and healthy functional properties such as anti-inflammatory activity. However, it is usually discarded after its roots are harvested. For wide application of danggui leaf, squeezed danggui leaf juice was used for making pan bread. Treatments included imported wheat flour (IMWF) and domestic wheat flour (DOWF) as a control, 1% soluble solid contents of squeezed danggui leaf juice instead of wheat flour (1% SDLJ), 2% SDLJ, 3% SDLJ, and 4% SDLJ. In the fermentation expansion, dough volume was not significantly different between DOWF and 1% SDLJ, whereas it decreased according to increased amount of squeezed danggui leaf juice. Regarding physical properties, springiness and cohesiveness decreased according to increased amount of squeezed danggui leaf juice and longer storage period. Gumminess, brittleness, and hardness increased according to increased amount of squeezed danggui leaf juice, although these were not statistically different among IMWF, DOWF, and 1% SDLJ after making pan bread. Principal component analysis (PCA) was performed to assess the correlation between storage period and physical properties. In the PCA, variance proportion of principal component (PC) 1 was 0.87 while that of PC 2 was 0.10. Further, 1% SDLJ showed similar results as DOWF and INWF after making pan bread and after 3 days of storage. In conclusion, use of 1% SDLJ is desirable for making squeezed danggui leaf juice.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.193-214
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• 2017

This study was carried out to identify the reality of students' understanding of Korean traditional scientific knowledge (TSK), the educational contexts influenced their understanding of TSK, and their sense of value of TSK, through the science activity 'Being a commentator on Korean traditional scientific culture' as a way of finding direction to apply TSK to science education while maintaining the inherent meaning of our traditional science. Seventh grade students have discovered TSK contents in Changdeok Palace, prepared their own scripts for seven months, and finally, explained to fifth to sixth grade students. The video recordings of all lessons, scripts of explanation, reports of field activities, and individual interviews were all analyzed. Students understood TSK in four viewpoints: the traditional view of nature, the traditional science and technology, the traditional life using science, and the natural science contents. During their activities, communication with peers or elders both in classroom and in Changdeok Palace, the interaction with place, and the sense of responsibility as a commentator helped students understand the scientific aspects of TSK, form contextual and sensible scientific knowledge, and apprehend various scientific explanations of contents. Depending on their internalization of experiences, the students' experiences produced three types of interpretation: delivery, persuasion, and understanding. Students formed their TSK sense of value as scientific characteristics, the need of new perspective about science, the need to protect and maintain TSK as our culture. The results of this study show that TSK can provide integrated and actual contextual education in science education and can be used to understand the cultural diversity of scientific and scientific methods and the characteristics of oriental scientific thinking. In addition, the simultaneous approach of TSK and school science to traditional culture can contribute to ideal concept formation and subjective attitude toward our traditional culture.

• Journal of Intelligence and Information Systems
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• v.23 no.1
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• pp.127-141
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• 2017

Advances in Internet technologies and the proliferation of mobile devices enabled consumers to approach a wide range of goods and services, while causing an adverse effect that they have hard time reaching their congenial items even if they devote much time to searching for them. Accordingly, businesses are using the recommender systems to provide tools for consumers to find the desired items more easily. Association Rule Mining (ARM) technology is advantageous to recommender systems in that ARM provides intuitive form of a rule with interestingness measures (support, confidence, and lift) describing the relationship between items. Given an item, its relevant items can be distinguished with the help of the measures that show the strength of relationship between items. Based on the strength, the most pertinent items can be chosen among other items and exposed to a given item's web page. However, the diversity of the measures may confuse which items are more recommendable. Given two rules, for example, one rule's support and confidence may not be concurrently superior to the other rule's. Such discrepancy of the measures in distinguishing one rule's superiority from other rules may cause difficulty in selecting proper items for recommendation. In addition, in an online environment where a web page or mobile screen can provide a limited number of recommendations that attract consumer interest, the prudent selection of items to be included in the list of recommendations is very important. The exposure of items of little interest may lead consumers to ignore the recommendations. Then, such consumers will possibly not pay attention to other forms of marketing activities. Therefore, the measures should be aligned with the probability of consumer's acceptance of recommendations. For this reason, this study proposes a model-based approach to combine those measures into one unified measure that can consistently determine the ranking of recommended items. A regression model was designed to describe how well the measures (independent variables; i.e., support, confidence, and lift) explain consumer's acceptance of recommendations (dependent variables, hit rate of recommended items). The model is intuitive to understand and easy to use in that the equation consists of the commonly used measures for ARM and can be used in the estimation of hit rates. The experiment using transaction data from one of the Korea's largest online shopping malls was conducted to show that the proposed model can improve the hit rates of recommendations. From the top of the list to 13th place, recommended items in the higher rakings from the proposed model show the higher hit rates than those from the competitive model's. The result shows that the proposed model's performance is superior to the competitive model's in online recommendation environment. In a web page, consumers are provided around ten recommendations with which the proposed model outperforms. Moreover, a mobile device cannot expose many items simultaneously due to its limited screen size. Therefore, the result shows that the newly devised recommendation technique is suitable for the mobile recommender systems. While this study has been conducted to cover the cross-selling in online shopping malls that handle merchandise, the proposed method can be expected to be applied in various situations under which association rules apply. For example, this model can be applied to medical diagnostic systems that predict candidate diseases from a patient's symptoms. To increase the efficiency of the model, additional variables will need to be considered for the elaboration of the model in future studies. For example, price can be a good candidate for an explanatory variable because it has a major impact on consumer purchase decisions. If the prices of recommended items are much higher than the items in which a consumer is interested, the consumer may hesitate to accept the recommendations.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.267-276
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• 2015

The gallbladder(GB) polyps have malignant potential and nowadays are increasing due to the extended use of ultrasonography. Even though there are various reports on the risk of GB polyps, there is few study on the relationship between the presence of metabolic syndrome including serum biochemistry, lifestyle and the development of gallbladder polyps in korean population. The aim of this study is to establish a relationship between the presence of metabolic syndrome including serum biochemistry and the development of gallbladder polyps in korean population. This study conducted on 151 men and 167 women who visited a musculoskeletal hospital in Gyeonggido to have an ultrasound scan of the abdomen from November 2, 2012 to January 31, 2014. They are randomly selected to evaluate the prevalence risk factors were analyzed by comparing various variables between the GB polyp positive and negative. The collected data were analyzed using the personal computer program SPSS version 20.0 for windows. The mean size of the GB polyps was 3.92mm in diameter. Size of GB polyps were less than 10mm in diameter. As to frequency in the people with the GB polyps, the number of patients with the GB polyps was 184(57.9%): the number of metabolic syndrome of them was 114(26.4%); these results showed that risk of the GB polyps got higher at patients with metabolic syndrome. As to the risk of the GB polyps, people with the GB polyps had significantly higher risk than those without the GB polyps, as follows: The risk was significantly 1.061 times higher by weight; 1.186 by BMI; 1.060 by systolic blood pressure; 1.030 by diastolic blood pressure; 1,009 by Total cholesterol; 2.736 by metabolic syndrome; 1.011 by blood sugar on an empty stomach; 1.064 by ESR. The risk factors of GB polyps were found to be weight, BMI, total cholesterol, Triglycerol, Glucose, systolic blood pressure, diastolic blood pressure, ESR and metabolic syndrome. This study has a possibility to be used an indicator to identify the GB polyps, and in the future larger-scale study will have to be conducted to objectify it.

• Analytical Science and Technology
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• v.28 no.6
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• pp.417-424
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• 2015

In this study, the relationship between selenoprotein concentrations in blood and stomach cancer have been searched for Korean. The concentration of each selenoprotein in blood serum was analyzed and the correlation between the concentration and stomach cancer was studied to find a potential for using Selenium as a biomarker. In concentration determination, a simple calibration curve method was used with the monitoring of m/z 78 without the use of solid phase extraction. This is a lot more simple than the method using SPE with post column isotope dilution. The result obtained from the analysis of CRM BCR-637, 72.20±3.35 ng·g⁻¹, showed similar value of reference value (81±7 ng·g⁻¹). The total concentration of Se for the controlled group, cardiovascular patients group, was 105.70±21.20 ng·g⁻¹. This value was the same as normal healthy person reported earlier. Each selenoprotein concentration of GPx, SelP and SeAlb was 26.12±7.84, 65.15±14.50, 14.43±6.99 ng·g⁻¹, respectively. The distribution of each selenoprotein was 24.7%, 61.6%, and 13.7%, which was similar to the normal person. The result of stomach cancer patients, the total concentration of Se was 76.11±28.12 ng·g⁻¹ and each concentration of GPx, SelP and SeAlb was 15.41±9.01, 50.83±17.91, and 9.87±5.21 ng·g⁻¹, respectively. The total and each selenoprotein concentration level showed significant decrease for the stomach cancer patients. The level of decrease was 41.0% for GPx, 22.0% for SelP, and 31.6% for SeAlb. However, the distribution of each selenoprotein was not much different. Either total Selenium or each selenoprotein could be used as a possible index for the diagnosis of cancer. However, in age group study, it is shown that young age group (30's-40's) did not show much difference.

• Analytical Science and Technology
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• v.28 no.6
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• pp.453-459
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• 2015

Split-flow thin cell fractionation (SPLITT fractionation, SF) is a particle separation technique that allows continuous (and thus a preparative scale) separation into two subpopulations based on the particle size or the density. In SF, there are two basic performance parameters. One is the throughput (TP), which was defined as the amount of sample that can be processed in a unit time period. Another is the fractionation efficiency (FE), which was defined as the number % of particles that have the size predicted by theory. Full-feed depletion mode (FFD-SF) have only one inlet for the sample feed, and the channel is equipped with a flow stream splitter only at the outlet in SF mode. In conventional FFD-mode, it was difficult to extend channel due to splitter in channel. So, we use large scale splitter-less FFD-SF to increase TP from increase channel scale. In this study, a FFD-SF channel was developed for a large-scale fractionation, which has no flow stream splitters (‘splitter less’), and then was tested for optimum TP and FE by varying the sample concentration and the flow rates at the inlet and outlet of the channel. Polyurethane (PU) latex beads having two different size distribution (about 3~7 µm, and about 2~30 µm) were used for the test. The sample concentration was varied from 0.2 to 0.8% (wt/vol). The channel flow rate was varied from 70, 100, 120 and 160 mL/min. The fractionated particles were monitored by optical microscopy (OM). The sample recovery was determined by collecting the particles on a 0.1 µm membrane filter. Accumulation of relatively large micron sized particles in channel could be prevented by feeding carrier liquid. It was found that, in order to achieve effective TP, the concentration of sample should be at higher than 0.4%.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.53-59
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• 2007

A safety management rule of the diagnosis radiation system which opened a court 2006 February 10th was promulgated for safety of the radiation worker, patients and patients' family members. The purpose of this study is to minimize injury by radiation that can happen to patients and people around a sick ward when managing mobile X-ray system. This study analyzed sickroom environment of mobile X-ray examination and the statistical data of the Konkuk medical Information System(KIS) and the Picture Archiving Communication System(PACS). This study also investigated patient conditions, infection, relation information and related data, when the sickroom mobile X-ray examination is used. Through data analysis, many problems were expected such as restriction of space side, manpower and expense of business side, satisfaction degree decline of patient and protector of operation side. Therefore, we tried to restrict examination of multi bed sickroom, and to use treatment room in each ward to solve problem mentioned. As a result, the whole sickroom mobile X-ray examination rate decreased to near 50%, and mobile X-ray examination rate for inpatients decreased to more than 85%. This study shows that several attempts we did should be helpful for manpower, patients satisfaction and expenses. Also, they should protect patients in sickroom from unnecessary radiation exposure and could minimize inconvenience of patients and their family members from x-ray examination.

• Journal of Korea Water Resources Association
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• v.40 no.10
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• pp.769-781
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• 2007

Factor analysis has been usually employed in reducing quantity of data and summarizing information on a system or phenomenon. In this analysis methodology, variables are grouped into several factors by consideration of statistic characteristics, and the results are used for dropping variables which have lower weight than others. In this study, factor analysis was applied for extracting primary factors influencing multi-dam system operation in the Han River basin, where there are two multi-purpose dams such as Soyanggang Dam and Chungju Dam, and water has been supplied by integrating two dams in water use season. In order to fulfill factor analysis, first the variables related to two dams operation were gathered and divided into five groups (Soyanggang Dam: inflow, hydropower product, storage management, storage, and operation results of the past; Chungju Dam: inflow, hydropower product, water demand, storage, and operation results of the past). And then, considering statistic properties, in the gathered variables, some variables were chosen and grouped into five factors; hydrological condition, dam operation of the past, dam operation at normal season, water demand, and downstream dam operation. In order to check the appropriateness and applicability of factors, a multiple regression equation was newly constructed using factors as description variables, and those factors were compared with terms of objective function used in operation water resources optimally in a river basin. Reviewing the results through two check processes, it was revealed that the suggested approach provided satisfactory results. And, it was expected for extracted primary factors to be useful for making dam operation schedule considering the future situation and previous results.