• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.171-174
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• 2022

Cosmetic packing materials tend to be difficult to recycle when discarded due to the cosmetic industry's pursuit of aesthetics, functionality, and high value-added design. Pump packaging, which is widely used for the good preservation and discharge of cosmetics contents, is difficult to be separated and recycled because of a metal spring, which is in charge of pump resilience. In this study, a polypropylene spring was developed to replace the existing metal spring to improve the recyclability of the pump packaging for cosmetics, and was uni-materialized by applying to the cosmetic packing materials with 0.2 ml of discharge amount. In addition, performance test was conducted to verify the equivalence with the existing metal spring pumps as grounds for the commercialization of metal-free uni material pump packaging. The decompression leak test showed no leakage and displayed 14.8~17.5 N of pressing strength, 2.3~8.8 % of deviation in dispensing volume, and 4 occasions of pumping for initial discharge.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.55-67
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• 2022

This study applied the dynamic cone penetrometer test (DCPT) and light-weight deflectometer test (LWDT) to the quality control of subgrade base by performing DCPT, LWDT, and plate load test (PLT) at two earthwork sites. Although DCPT and LWDT were performed under the same conditions, the results showed significant variation with the test location. Because the measured value at the time of the initial blow, which varies depending on the test location, significantly influenced the test result. Thus, it was appropriate to ignore the first two blows as preliminary blows and use subsequent measurements as quality control indicators. In addition, DCPT, LWDT, and PLT results showed a high correlation under the same conditions. Especially regression analyses using averaged data for each experiment condition tended to yield significantly improved R² values over individual point data sets. This indicates that average DCPT and LWDT values at various adjacent locations are better quality control indicators for subgrade bases than individual point values.

• Korean Journal of Culture and Social Issue
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• v.28 no.3
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• pp.331-352
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• 2022

This study used a latent growth curve models(LGCM) to examine longitudinal changes in youth's game usage, self-control and the longitudinal mediation effect of adaptive game use in the relationship between game usage and self-control. A four-year longitudinal data of 863 adolescents from the Game User Panel Survey, provided through participation in the 2019 Game User Panel Research Conference hosted by the Korea Creative Contents Agency, was used to verify the longitudinal mediation effect of adaptive game use. SPSS 21 was used to verify the normality of variables from each wave, and to conduct correlation analysis. Mplus 6.12 was used to verify the longitudinal mediation effect. The results are as follows. First, game usage, self-control and adaptive game yielded linear temporal growth. Second, latent growth curve models showed that the direct effect of game usage on self-control was insignificant, but game usage had a significant indirect effect on self-control through adaptive game use. Continuous adaptive gaming increased self-control. Third, sobel test results showed that both the initial value and change rate of adaptive game use had a full-mediation effect, confirming the longitudinal mediation effect. This study verified the longitudinal change of self-control affected by change in game usage and adaptive game use.

• Korean Journal of Organic Agriculture
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• v.30 no.2
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• pp.279-290
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• 2022

This study was conducted to find out that winter green manure crops could be efficient replacements of expeller cake fertilizers, which were mostly imported, on environment-friendly red pepper production. Four treatments were compared under the condition of plastic film house: 1) barley (B); 2) hairy vetch (HV); 3) mixtures of barley and hairy vetch (B/HV); 4) expeller cake (EC). Total nitrogen content in hariy vetch was 3.6%, which was higher than 1.5~1.8% in barley and mixtures of barley and hairy vetch. P₂O₅ and K₂O contents were similar in all green manures. Supplying amount of nitrogen from B, HV and B/HV plot, which were 172 kg ha^-1, 193 kg ha^-1, and 198 kg ha^-1, were higher than amount of basal nitrogen required by soil testing but were lower than that of total nitrogen, respectively. Among the green manure crops, C/N ratio of HV was the lowest at 11.8, showing a similar value to that of expeller cake, but that of B was the highest at 30.6. Total yield was no significant difference in all treatment plots although B/HV plot showed the highest yield, but initial yield in B plot with high C/N ratio was lower than that in EC plot.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.163-174
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• 2020

The purpose of this study is to derive the characteristics of the creative process of convergence performing arts. Therefore, the PADAF-Play and Dance Art Festival, a representative convergence performing arts festival in Korea that has been held steadily every year since the first event in 2011, was selected as the subject of the study. Through PADAF, a representative convergence performing arts festival in Korea, qualitative case studies were selected through process-oriented discovery to study the characteristics of the creative process of convergence performing arts, which is a key feature of performing arts in the 21st century. For realistic and empirical research, the 8th and 9th PADAF participated in the entire process from the initial stage of preparation to the closing ceremony and conducted several in-depth interviews with PADAF officials and participating artists. Looking at the characteristics of the convergence performance art creation process through PADAF, creators overcame difficulties that they had not thought of in different ways in the process of meeting different heterogeneous genres, but through understanding other genres, experiential values through convergence, sharing as collaborators, and various ways of communication. The characteristics of the convergence performing arts creation process, which is focused on PADAF, are "Rhizom thinking" by French philosopher Gilles Deleuze(1925-1995), "Collective intelligence," and "Experimental Value for Experimental Creation" by creators. Through this derivation, we will help the changing performing arts scene based on the basic human desire to understand convergence performance art a little more and communicate through the extended expression of convergence.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.105-113
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• 2022

Mulching film was produced by LDPE and LLDPE adding biomass byproducts and MA(maleic anhydride), talc/clay/CaO/CaCO₃. And also surveyed to tensile strength, elongation, TGA and DSC according to the UV irradiation time. The tensile strength and elongation showed 20 N/cm² and 5% after UV irradiation 100 hours, and those was nearly 0 N/cm² and 0% after 200 hours, respectively. TGA of film was showed to peak of polymer itself, and DSC was slightly higher than that of initial value. At the pilot scale test, we were able to see the differentiate of degradation between control and developed film after 12 weeks, and also torn off at several part of mulching film. The degradation of mulching film after growing corn showed similar to a pilot scale test. Above the results, the developed mulching film adding biomass will be to used for agricultural farming.

• Korean Journal of Construction Engineering and Management
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• v.23 no.3
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• pp.66-73
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• 2022

In order to induce users to purchase excellent products in the water industry that satisfy the technical standards of excellent products, in this study, it is to present the advantages of the cost aspect of the pumps as the objective basis. It will be to promote technology development of domestic water companies and to create a virtuous cycle structure in the water industry. In order to present an objective basis for the merits in terms of cost, an economic evaluation was conducted through life cycle cost analysis. For the LCC analysis, initial cost (pump cost and installation cost), operation cost (energy cost and maintenance cost) and demolition cost (disposal cost and residual value) are searched and calculated. As the results of comparison on two capacity of pumps, the energy cost of the excellent pump is 212 million KRW lower than the that of general pump in the large pump. The cost of excellent pump was 17 million KRW lower than that of general pump in small capacity pump. As the results of sensibility test, if the product is developed in the direction of improving pump efficiency and increasing the replacement cycle of consumables, it is predicted that the effect on LCC will be large.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.578-585
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• 1996

This experiment was carried out to obtain the basic informations on yield performance and physicochemical quality properties of North Korean rices at southern high altitude area, Unbong and southeren plain area, Iksan. North Korean cultivars showed significant difference in number of spikelets per panicle, percentage of ripened grain and yield between two locations, but not significant in number of panicle per hill and l000-grain weight. The highest contribution to grain yield was the percentage of ripened grain and l000-grain weight at Iksan and Unbong, respectively, The protein, amylose content, alkali digestion value and Mg/K ratio showed larger variation in varieties than that in the locations cultivated. Mg and K revealed highly significant variations in locations, varieties and variety $\times$ location (V$\times$L) interaction. The amylogram characteristics such as initial pasting temperature, peak, breakdown, setback and consistency viscosities showed highly significant variation in locations, varieties and V$\times$L interaction. The physical characteristics of cooked rice such as adhesiveness, gumniness and chewiness also showed highly significant variations in locations, varieties and V$\times$L interaction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.524-530
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• 1993

The experiment was carried out to investigate the changes in physicochemical properties of milled rice harvested in different year and stored for four to sixty four months. The fat acidity of milled rice increased sharply from four to sixteen months storage, and after then it was increased slowly to sixty four months. Amylose, magnesium, potassium content, and K/Mg ratio of milled rice were not changed by storage duration. Water absorption rates of milled rice at 21$^{\circ}C$ and 77$^{\circ}C$, and alkali digestion value were increased by longer storage duration. Difference of water absorption rate between rice samples was greater during initial forty minutes after soaking at 21$^{\circ}C$ and with longer the soaking time at 77$^{\circ}C$. Shorter gel length of rice flour was found with prolonged storage duration, while peak, minimum, cool, breakdown and setback viscosity of gelatinized rice flour on amylograph were increased along with increasing the storage duration. The volume expansion rate during cooking and degree of iodine coloration of cooking water were higher in the longer stored rice compared with shorter one, and the amount of soluble solid in cooking water was significantly decreased in rice stored longer period.

• Geophysics and Geophysical Exploration
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• v.26 no.3
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• pp.138-149
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• 2023

In geoscience and engineering the geological characteristics of sediment strata is crucial and possible if reliable borehole logging and seismic data are available. To investigate the characteristics of the shallow strata in the Korea Strait, laboratory sonic logs were obtained from deep borehole data and seismic section. In this study, we integrated and analyzed the sonic log data obtained from the drilling core (down to a depth of 200 m below the seabed) and multichannel seismic section. The correlation value was increased from 15% to 45% through time-depth conversion. An initial model of P-wave impedance was set, and the results were compared by performing model-based, band-limited, and sparse-spike inversions. The derived P-impedance distributions exhibited differences between sediment-dominant and unconsolidated layers. The P-impedance inversion process can be used as a framework for an integrated analysis of additional core logs and seismic data in the future. Furthermore, the derived P-impedance can be used to detect shallow gas-saturated regions or faults in the shallow sediment. As domestic deep drilling is being performed continuously for identifying the characteristics of carbon dioxide storage candidates and evaluating resources, the applicability of the integrated inversion will increase in the future.