• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.191-200
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• 2017

Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.5
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• pp.514-523
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• 2004

Statement of problem: All-ceramic restorations have been advocated for superior esthetics. Various post and core systems have been used to improve the strength of damaged teeth, but it is unclear whether they affect the final shade of finished all-ceramic restorations. Purpose: The influence of different types of post and core systems on light transmission through all-ceramic crowns was assessed by spectrophotometric analysis. Also the masking effect of different thickness of ceramic ingot was evaluated. Material and Methods : Forty-five sample disks (15mm in diameter) at several thickness(1.0, 1.5, 2.0mm) and value(shade 100, 200, 300) were made in heat pressed ceramic(IPS-Empress). Background specimens simulating gold-alloy cast posts(Type III casting gold alloy), metal posts(Ni-Cr casting alloy) and ceramic posts(CosmoPost) were fabrica-ted. Resin composite(Z250, A3 shade) was used as a tooth substrate reference. For each combination, the change in color was measured with a spectrophotometer. Readings were performed for 2 conditions (1) ability of ceramic to mask the core in relation to its thickness(1.0, 1.5, or 2.0mm) ; (2) influence of post and core types on the final color of the ceramic. Data were recorded according to the CIE $L^*a^*b^*$ systems and color difference($\Delta$E) was calculated. Results: 100 shade ingot: when ceramic thickness was 1.0mm, $\Delta$E value for ceramic post larger than 1 but $\Delta$E value for metal and gold post was larger than 2. For ceramic thickness of 1.5mm, only $\Delta$E value for metal was larger than 2, and the other samples' $\Delta$E value was smaller than 2. For ceramic thickness of 2.0mm, $\Delta$E values for all specimens was smaller than 2. 200 shade ingot: when ceramic thickness was 1.0mm, $\Delta$E value for ceramic post was smaller than 1 but $\Delta$E value for metal and gold post was larger than 2. For ceramic thickness of 1.5 mm, only the $\Delta$E value for metal was larger than 2, and the other samples' $\Delta$E value was smaller than 2. For ceramic thickness of 2.0mm, $\Delta$E values for all specimens was smaller than 1. 300 shade ingot: when ceramic thickness was 1.0mm, only $\Delta$E value for metal was larger than 2 and the other samples' $\Delta$E value was smaller than 2. For ceramic thickness of 1.5mm, $\Delta$E values for all specimens was smaller than 1. For ceramic thickness of 2.0mm, $\Delta$E values for all specimens was smaller than 1. Conclusion: The final esthetic result of the IPS-Empress glass-ceramic restoration was not affected by the presence of different core materials when the thickness was more than 2.0 mm. When ceramic thickness decreases to 1.5mm, it is advised to take the substrate aspects into consideration. If the ceramic thickness is less than 1.0mm, using the tooth color matched substrate is strongly recommended.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.877-884
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• 2013

This study investigated the optimal composition of sugar and artificial sweeteners in oatmeal cookies. Modified cookies were examined for their quality characteristics and glycemic index in humans. Oatmeal cookies with various amounts of sugar (20, 30, or 40%) were made to the equivalent sweetness of 100% sugar cookies (the control) with sucralose and stevioside. The density and acidity of cookie dough were not significantly different between the different cookie groups. However, baking loss and the spread index were significantly lower in the 100% sugar cookie group compared to cookies supplemented with artificial sweeteners. The color lightness (L value) and redness (a value) were highest in 30% and 100% sugar cookies, respectively. The strength of the cookies was negatively correlated with sugar content. In sensory evaluations, scores for taste, color and texture were higher in 30% and 40% sugar cookies, respectively, but the overall preference was higher in 30% sugar cookies. We therefore tested 30% and 100% sugar cookies for their glycemic index in college students. After overnight-fasted students consumed either 30% or 100% sugar cookies (containing 50 g of carbohydrate in dough weight), blood glucose levels increased 27.8 and 15.7 mg/dL, respectively, at 1 hour from the baseline. However, at 2 hours from the baseline, students who consumed 100% sugar cookies had a remarkably lowered blood glucose levels. Students who consumed 30% sugar cookies did not have as much of a change in blood glucose levels. In conclusion, 30% sugar oatmeal cookies made with sucralose and stevioside can be used to make a low-sugar cookie with a low glycemic index.

• Journal of Korean Medical classics
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• v.7
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• pp.198-231
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• 1994

Up to now, after I had examined the relation between the origin of Fung(風) and Gi(氣) and the mean of Fung in medical science, I obtained the conclusion being as follows. The first, Fung(風) means a flux of Gi(氣) and Gi shows the process by virtue of the form of Fung, namely, Fung means motion of Gi. In other words, it is flow of power. Accordingly, the process of all power can give a name Fung. The second, Samul(事物) ceaselessly interchange with the external world to sustain the existence and life of themselves. And they make a adequate confrontation against the pressure of the outside. This the motive power of life action(生命活動) is Gi and shows its the process on the strength of Fung. The third, Samul(事物) incessantly releases power which it has to the outside. Power released to the outside forms the territory of the established power in the environment of them and keep up their substance(實體) in the space time(時空). It can be name Fung because the field(場) of this power incessantly flows. The fourth, man operates life on the ground of the creation of his own vigor(生氣) for himself as the life body(生命體) of the independence and self-support. The occurence of this vigor and the adjustment process(調節作用) is supervised by Gan(肝). That is to say, Gan plays a role to regulate and manage the process of Fung or the action of vigor with Fung-Zang(風臟). The fifth, because the Gi-Gi adjustment process(氣機調節作用) of Gan is the same as the process of Fung, Fung that operates the cause of a disease is attributed to the disharmony of the process of the human body Gi-Gi. Therefore, the generating pathological change is attributed to the extraordinary of the function by the incongruity of Gi-Gi(氣機) or the disorder of the direct motion of Gi-Hyul(氣血). Because the incongruity of this Gi-Gi of the human body gives rise to the abnormal of Zung-Gi(正氣) in the human body properly cannot cope with the invasion of 'Oi-Sa(外邪). Furthermore, Fung serves as the mediation body of the invasion of other Sa-Gi(邪氣) because of its dynamics, By virtue of this reason, Fung is named the head of all disease. And because the incongruity of the Gi-Gi has each other form according to Zang-Bu(臟腑), Kyung-Lak(經絡), and a region, the symptoms of a disease appear differently in line with them as well. The sixth, Fung-byung(風病) is approximately separated Zung-Fung(中風) and Fung-byung(猍義의 風病). Zung-fung and Fung-byung is to be attributed to the major invasion of each Jung-gi and Fung-sa(正氣와 風邪). But these two kinds stir up the problem to the direct motion of Gi-hyul(氣血) and the harmony of Gi-Gi in the human body. When one cures it, therefore, Zung-fung has to rectify Gi-Gi and the circulation of Gi-hyul on the basis of the supplement of Jung-gi(正氣) and Fung-byung must make the harmony of Gi-Gi with the Gu-fung(驅風). -Go-gi(調氣), Sun-Gi(順氣). Hang-Gi(行氣) - All existing living things as well as man maintain life on the ground of the pertinent harmony between the soul(精神) and the body(肉體). As soon as the harmony falls down, simultaneously life disappears as well. And Fung which means the outside process between Gi(氣) and Gi(氣) makes the action of their life cooperative and unified, Accordingy, the understanding of Fung, first, has to start wi th the whole thought that not only all Samul(事物) but also the soul and the body are one.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.1-7
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• 2018

As part of a research dedicated to the field evaluation of the durability of concrete subjected to freezing-thawing, this study analyzes the relationship between the surface roughness and the relative dynamic elastic modulus through image analysis. Four mix compositions with water-to-binder ratios (W/B) of 40%, 50%, 60% and 70% and without AE agent were considered to provoke early freezing. The basic physical properties of the mixes including the relative dynamic elastic modulus and the compressive strength were first evaluated experimentally according to W/B. Then, tests were performed to measure the surface roughness followed by photographs and SEM image analysis. The measured surface roughness tended to increase with larger number of freezing-thawing cycles regardless of W/B. The relative dynamic elastic modulus appeared to increase gradually with the number of cycles for the relatively denser mixes with W/B of 40% and 50%. Besides, the surface roughness increased only at rupture for the mixes with W/B of 60% and 70%. Moreover, the analysis of the photographs of the surface of the mixes with W/B of 40% and 50% revealed that the degradation progressed gradually from the surface with the freezing-thawing cycles. However, for the mixes with W/B of 60% and 70%, apparent change of the surface remained very insignificant until rupture at which damage like cracking could be observed. Consequently, the analysis of surface photograph or the measurement of the surface roughness presented some limitation in assessing the degree of freezing-thawing-induced degradation in case of relatively porous specimens. On the other hand, the photograph and surface roughness appeared to be sufficient for assessing such degradation for the mixes with W/B of 40% and 50%. Accordingly, the image of the surface and the surface roughness are potentially applicable on site for the assessment of freezing-thawing damages in relatively dense mixes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.27-35
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• 1986

In succession to the previous paper, the present study was directed to investigate the effect of keeping freshness of conger eel (Astroconger myriaster) and yellowtail (Seriola quinqueradiata) by partial freezing, and the changes in the physical properties of fish meat paste product prepared with the muscle of conger eel during storage were also examined. The results obtained are summarized as follows: The period of keeping freshness (days in which k value reaches $20\%$) of conger eel and yellowtail by partial freezing was 10 days and 6 days, respectively. VBN content in the conger eel muscle showed 39.5 mg/100g by icing for 15 days, and did not show a great change by partial freezing and freezing, while that of yellowtail muscle reached at 32 mg/100g by icing, 20 mg/100g by partial freezing and 18 mg/100g by freezing for 15 days. The lipids extracted from the muscles of both fishes by icing were remarkably oxidized than those by partial freezing. The myofibrillar protein in the conger eel muscle during storage for 9 days decreased $3\%,\;10%\;and\;11\%$ by icing, partial freezing and freezing, respectively, and that of yellowtail muscle did $16\%,\;10%\;and\;4\%$ by icing, partial freezing and freezing, respectively. On the other hand, the alkali-soluble protein in both fishes increased with storage time. Gel strength of fish meat paste product prepared with the muscle of conger eel decreased to $35\%$ by icing, $74\%$ by partial freezing and $76\%$ by freezing for 10 days compared to control, and the expressible water increased 1.6 times, 1.2 times and 1.1 times by icing, partial freezing and freezing, respectively, as much as that of control product.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.63-74
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• 2006

During the construction of circular underground pipe, the non-proper compaction along the pipe and the decrease of compaction efficiency have been the main problems to induce the failure of underground pipe or facility. The use of CLSM (controlled low strength materials) should be one of the possible applications to overcome those problems. In this research, the full-scaled field test and the numeric analysis using PENTAGON-3D FEM program were carried out for three different cases on the change of backfill materials, including the common sand, the soil from construction site, and the CLSM. From the full-scaled test in field, the use of in-situ CLSM as backfill materials reduced the vertical and lateral deformation of the pipe, as well as the deformation of the ground surface. The main reason for reducing the deformation would be the characteristics of the CLSM, especially self-leveling and self-hardening properties. The measured earth pressure at the surround of the corrugated pipe using the CLSM backfills was the smaller than the other cases, and the absolute value was almost zero. Judging from the full-scaled field test and FEM analysis, the use of CLSM as backfill materials should be one of the best choices reducing the failure of the underground pipes.

• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1109-1123
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• 2020

In South Korea with forest as a major land cover class (over 60% of the country), many wildfires occur every year. Wildfires weaken the shear strength of the soil, forming a layer of soil that is vulnerable to landslides. It is important to identify the severity of a wildfire as well as the burned area to sustainably manage the forest. Although satellite remote sensing has been widely used to map wildfire severity, it is often difficult to determine the severity using only the temporal change of satellite-derived indices such as Normalized Difference Vegetation Index (NDVI) and Normalized Burn Ratio (NBR). In this study, we proposed an approach for determining wildfire severity based on machine learning through the synergistic use of Sentinel-1A Synthetic Aperture Radar-C data and Sentinel-2A Multi Spectral Instrument data. Three wildfire cases-Samcheok in May 2017, Gangreung·Donghae in April 2019, and Gosung·Sokcho in April 2019-were used for developing wildfire severity mapping models with three machine learning algorithms (i.e., Random Forest, Logistic Regression, and Support Vector Machine). The results showed that the random forest model yielded the best performance, resulting in an overall accuracy of 82.3%. The cross-site validation to examine the spatiotemporal transferability of the machine learning models showed that the models were highly sensitive to temporal differences between the training and validation sites, especially in the early growing season. This implies that a more robust model with high spatiotemporal transferability can be developed when more wildfire cases with different seasons and areas are added in the future.

• Korean Security Journal
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• no.23
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• pp.65-86
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• 2010

The conclusion for this paper is as following as to plan for advancing security. First, Depending on situation, security martial arts technique is necessary in security work, but the case that the client need to be covered by security guards to avoid the danger often happens. If there is no self-sacrifice and loyalty to the clients, the meaningful security work is not completed in this situation. Therefore, the basic views on education of security leaders need to be defensive than aggressive, and be spirit-equipped than technical feature. Second, more time has to be taken training mentality along with focusing on technical education of security martial arts. To escape from danger spreaded around, security guards must be strong mentally and physically, then they are able to finish the situation. If someone is chosen as a security guard, one's physical strength is already approved. This means that the rest part for the perfect accomplishment is strict discipline on mental one's mind, and basically physical training has to be continued. In conclusion, The elements that the instructor has to acquire are not only extensive theoretical knowledge of the security martial arts and real experiences through techniques but also personality cultivation which maximize the morality training. Accordingly, this could bring the client personally change in perception of the security guard, furthermore greatly expand the academic and professional security work of security department.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.249-259
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• 2009

The objective of this research was to find out the physical properties, such as dispersion and coagulation, of soil minerals depending on the types and concentrations of the cations in aqueous solution. Hwangto samples were obtained from 90 to 130 cm from surface at Jangdong-ri, Donggang-Myon, Naju, Chonnam Province. The clay fraction (< $2\;{\mu}m$) was separated by sedimentation method from the bulk soils. Both Hwangto and clay fractions, and the same samples after removal of amorphous and crystalline iron oxides were used in this experiment. The effect of 4 cations ($Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$) and their concentrations on settling speed and basal spacing of the minerals were observed to examine the physical properties of the soil and clay minerals. Hwangto mainly consisted of quartz, and the clay fractions consisted of kaolinite, illite, and vermiculite. The bulk soils contained 16.3 mg/kg of amorphous iron oxides and 436 mg/kg of crystalline iron oxides. Clay fractions were dispersed better than bulk soils due to their smaller particle size than that of the bulk samples in the aqueous solution. The bulk and clay samples were dispersed better when iron oxides were removed because of coating of minerals by the iron oxides. Clay minerals were settled faster as the charge and the concentration of cations added increased. The d-spacing of kaolinite and illite did not change when 4 types of cations were added. The d-spacing of vermiculite showed $14.04\;{\AA}$ when divalent cations were added while that of vermiculite showed $13.9\;{\AA}$ when monovalent cations were added. It may be attributed to the hydration radii of cations. This study indicated that both coating of iron oxides on minerals and types and concentrations of cations affect dispersion of minerals in solution and d-spacing of expanding clay minerals such as vermiculite.