• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.2
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• pp.31-38
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• 2018

This study was conducted to investigate the possibility of biochar as an alternative medium to peatmoss using for Aster spathulifolius. We cultivated A. spathulifolius in four potting media with different mixing rates (v/v) of peatmoss (P) and biochar (B) as follows: B0+P3, B1+P2, B2+P1, and B3+P0 with vermiculite 3 + perlite 3. Also, we analyzed the chemical properties of media and the plant growth characteristics. The results were as follows: In case of media's chemical condition, B0+P3 and B1+P2 treatments showed higher tendency (p < 0.05). Plant height on B0+P3 and B1+P2 treatments was much higher than that on other treatments (p < 0.05). Root length on B1+P2 treatment was higher than on B0+P3 treatment (p < 0.05). B0+P3 and B1+P2 treatments showed higher number of leaves and dry biomass than other treatments. Therefore, our results support that Biochar : Peatmoss : Vermiculite : Perlite (1/3 : 2/3 : 1 : 1, v/v) could be a more economical potting medium for A. spathulifolius than peatmoss : vermiculite : perlite (1 : 1 : 1, v/v).

• Journal of Ocean Engineering and Technology
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• v.2 no.2
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• pp.78-86
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• 1988

In order to investigate the corrosion pit occurrence and growth characteristic of M.E.F.(martensite encapsulated islands of ferrite) dual phase steel was made with a suitable heat treatment of raw material(SS41), a corrosion fatigue test was performed under rotary bending in the salt solution having a concentration from 0.01 wt percent to 3.5 wt percent. The fatigue strength of dual phase steel was remarkably decreased with an increase in concentration of salt solution; approximately from 63% to 80% in case of dual phase steel and from 40% to 71% in case of raw material. Corrosion pit occurred in the martensite phase and fatigue cracks from corrosion pits were selectively propagated in martensite phases. In the observation of corrosion pits at the origin of fatigue cracks, it had been found that corrosion pits were grown into hemispherical pits and a/c(the surface diameter, 2c and the depth, a of corrosion pit)was about 1.0-1.5regardless of the variation of salt solution concentration. The difference of corrosion pit depth growth rate was increased with an increase in concentration of salt solution according to an increase in stress level.

• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.517-520
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• 2006

The effects of culture soil combinations on growth of native pteridophyte (Pteris multifida, Cyrtomium falcatum and Cheilanthes argentea) were investigated in this study. Six different culture soil mixtures used for cultivating the pteridophytes under 30% shading condition. Pteris multifida was showed the most growth at the culture soil mixtures of peatmoss : living moss (5 : 5), and peatmoss : perlite (7 : 3). Cyrtomium falcatum and Cheilanthes argentea showed the best growth in the culture soils mixtures of sand : soil : leaf mold (2 : 5 : 3) and peatmoss : perlite (7 : 3, 5 : 5), respectively.

• Journal of Korea Game Society
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• v.15 no.6
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• pp.17-28
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• 2015

This study attempted to identify differences in user experience and app game fun, satisfaction, use intention between fitness app games at different level of interaction design. The playtesting method was conducted on 100(male 50, female 50) university students using 'Enjoy Your Fitness', a fitness app game developed by The Center for Health Communication Studies. The results found that more interactive app game is higher in the level of user experience such as fitness accomplishment, flow, and interest. Fitness app game's fun, satisfaction, use intention is also higher on interactive fitness app game. As the study verified that interactive fitness app game had stronger effects in user fitness experience and user experience than general fitness app games through experimental studies, it may contribute to design fitness mobile app game for health improvement.

• Journal of Digital Convergence
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• v.13 no.6
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• pp.327-339
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• 2015

The present study explored how 1) individuals' perception about attributes of exercise/fitness apps and 2) their motivation for exercise/fitness behaviors influence perceived usefulness and usage of the apps. A survey of 323 males and females in their 20's and 30's revealed that attributes of apps that satisfy their basic psychological needs are crucial in promoting perceived usefulness and usage of the apps. Participants were more likely to perceive exercise/fitness apps useful as they perceive them having more attributes related to autonomy and competence. The perception regarding relatedness attributes did not have the main effect on perceived usefulness but showed an interaction effect with relative autonomous motivation. This convergence study which examined health apps from the perspectives of psychology and public health provides practical implications to development and evaluation of health apps.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.100-105
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• 2016

In this study we investigated the suitability of horticultural main organic root substrate materials (peatmoss, coir) for the development proper root substrate for working with bulb onion transplanter. We investigated seedling sprout ratio, growth and characteristics (bulk density, root substrate cohesion) those are suitable for mechanical transplanting by mixing with inorganic materials(red clay etc.). Although both seedling growth and root substrate bulk density were similar in peatmoss and coir based root substrates, we found that peatmoss mixing had higher root substrate cohesion compared to coir mixing. We assume that higher cohesion properties of peatmoss based root substrate will give more weight of root part during mechanical transplanting of young onion seedlings in the field. Because of this, we suggest that peatmoss is the appropriate ingredient for developing root substrates for working with bulb onion transplanter.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.15-22
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• 1996

Cucumbers(Cucumis sativus L. CV. SHARP 1) were cultivated by bag culture for 5 months to investigate the effect of substrates on growth, yield, and mineral contents. The substrates used in the experiment were vermiculite + perlite +peatmoss(1:1:1=V:V:V), perlite+peatmoss(1:1=V:V), perlite+carbonized chaff(7:3=V:V), rockwool, sawdust, and chaff+chaff powder under 10 mesh (7:3=V:V). The rate of moisture content was highest at chaff powder under 10 mesh as 42.5% and was lowest at perlite+carbonized chaff as 31%. Plant height, No. of leaves, fresh and dry weight were increased in vermiculite+perlite+peatmoss(1:1:1=V:V:V). Marketable fruits and yield also showed same aspect with growth. All kinds of mineral contents except K in cucumber plants were higher at vermiculite+perlite+peatmoss(1:1:1=V:V:V), but K content was higher at perlite+ carbonized chaff(7:3=V:V) than those other substrates.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.105-111
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• 1999

This study was performed about composting in a batch reactor of laboratory scale using garbage waste and swine waste. Sawdust and coconut peat were materials to control optimum moisture, C/N ratio and specific gravity in the study. Comparing compost using only sawdust with compost using sawdust and coconut peat, the latter was higher at reduction rate and decomposition rate. Coconut peat was accelerated aerobic fermentation, because it had moisture holding ability, initial moisture was low, ventilation was good and control of optimum specific gravity was possible. Compost by only garbage waste was under standard of manure. but mixtures in same proportion of garbage waste and swine waste producted high quality compost. CEC value was average 63.8me/100g. The initial C/N ratio of compost was regulated effectively because of high C/N ratio of sawdust. As the C/N ratio(>40) was higher, reduction rate was higher. During the composting C/N ratio was improved more and more.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.327-327
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• 2012

사파이어는 우수한 광학적, 물리적, 화학적 특성을 가지고 있는 물질 중의 하나이며, 청색 발광특성을 나타내는 GaN와 격자상수, 열팽창 계수가 가장 유사할 뿐만 아니라 가격도 상대적으로 저렴하기 때문에 GaN 성장을 위한 기판으로 사용될 수 있다. 실제로 사파이어는 프로젝터와 전자파 장치, 군사용 장비 등 다양한 분야에 응용되고 있으며, 발광 다이오드(LED)를 위한 기판으로 활용됨으로써 그 수요가 급격히 증가하고 있다. 그러나 사파이어 결정의 성장 중에 생길 수 있는 전위(dislocation)와 적층결함(stacking fault) 등의 결정 결함들은 결정 내에 존재하여 역학적, 전기적 성질에 큰 영향을 미칠 수 있다. 특히 사파이어가 청색 발광소자의 기판으로 사용되는 경우, 사파이어 기판 내부의 결정 결함은 증착되는 박막 특성에 영향을 미치게 된다. 따라서 사파이어의 보다 나은 응용을 위해서는 결정 결함에 대한 평가기술과 결함의 형성 메커니즘 등에 대한 이해가 필요하다. 특히, 결함의 정량적 평가 기술의 개발은 사파이어의 상용화에 중요한 핵심요소 중 하나이다. 결정을 산이나 염기 등을 이용하여 화학적 식각을 하게 되면 분자나 원자 간의 결합이 약한 부분이나 높은 에너지 상태에 있는 부분부터 반응을 하게 되는데, 이러한 반응을 통해 결정의 표면에 형성되는 것을 에치 피트(etch pit)라고 한다. 일반적으로 결정 내에 존재하는 전위는 높은 에너지 상태이므로, 이러한 에치 피트는 전위와 관련되어 있다. 따라서 사파이어 결정과 같은 결정질 물질은 표면의 식각을 통하여 관찰되는 에치 피트 등의 형상이나 반응성 등을 평가하여 결정 특성을 연구할 수 있다. 본 연구는 화학적 식각법으로 사파이어 결정의 특성을 평가하기 위하여 진행하였다. 사파이어 결정의 식각을 위하여 다양한 산-염기 용액들이 사용되었다. 식각 용액의 종류에 따른 사파이어 결정의 식각거동을 연구하고, 표면에 나타나는 형상을 연구하여 사파이어 결정의 구조적 특성을 파악하였다. 특히, 에치 피트 형성거동의 시간 및 온도 의존성에 관한 연구를 진행하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.661-663
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• 2015

It is currently being used or being developed mobile fitness application systems associated with the most obese. These systems give or notify the user to reduce the weight, check your momentum to inform your calories burned. However, the accuracy is low because it provides and manages the common data without considering the individual characteristics or the environment of the user. In this paper analyzes the disadvantage of mobile fitness system. To solve this problem it presents the data sharing mechanism to alert you to the exercise equipment with the other users belonging to the BMI group, such as yourself. And it proposes the design of a mobile fitness system which is based on the data sharing mechanism.