• 한국식품과학회지
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• 제25권6호
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• pp.742-746
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• 1993

DSC에 의한 노화양상에서 호화시킨 다음 냉각하여 3시간 후에 다시 가열하였을 때의 enthalpy를 서로 비교한 결과 강남콩의 enthalpy가 가장 크게 나타나 노화가 빨리 일어났다. 반면 동부나 녹두는 노화가 느리게 일어났다. Avrami 방정식을 이용하여 $4^{\circ}C$에서 저장한 1% 전분현탁액의 노화속도를 시험한 결과에서도 비슷한 경향을 보였다. 저장중 8% 전분겔의 수축현상으로부터 강남콩이 가장 빨리 수축되어 이장현상이 컸으며, 팥도 상당히 수축되었고, 비교적 동부와 녹두는 적게 수축되어 이장현상이 적었다. 또한 저장중 8% 전분겔의 water mobility behavior에서의 변화는 동부와 녹두의 경우 1일까지 거의 변화가 없다가 그 이후 서서히 감소되었으나 팥과 강남콩의 경우 처음에는 water mobility가 적어 겔이 빨리 형성되고 물의 결합정도가 크나 1일 동안 저장하였을 때 water mobility가 상당히 증가된 것으로 나타나 단시간내의 겔의 결합력이 크게 감소된 것으로 나타났다.

• 한국ITS학회 논문지
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• 제20권3호
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• pp.47-58
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• 2021

최근 국내 PM 시장의 성장과 다수의 전동킥보드 공유 서비스 등장으로 이용자 수가 급증하면서 PM 관련 민원 및 안전사고 발생이 증가하고 있는 추세이다. 이에 따라, PM 조작 및 운행 미숙으로 인한 사고 감소 방안으로 PM 교육·연습 공간의 필요성이 대두되고 있다. 본 연구에서는 PM의 체계적 운영 및 활성화 방안을 마련하기 위해 관련 갈등 요소를 분석하고 그 대안으로 PM 플레이그라운드 운영 및 PM 시범구역 운영 방법을 검토하여 제안하였다. PM 플레이 그라운드 운영을 통한 기초데이터 수집 및 초보운전자 행태 분석으로 이용자의 운행 안전성 개선이 가능하며, 안전성 확보를 위한 시설 설치 방안을 통해 이용자와 비이용자 간 다양한 이해관계의 갈등 해소가 가능할 것으로 기대된다.

• 한국수소및신에너지학회논문집
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• 제34권4호
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• pp.342-349
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• 2023

In this study, a numerical simulations were conducted to analyze the phase change behavior of a liquid hydrogen storage container. The effects of gravity direction and hydrogen filling rate on boil-off gas (BOG) in the storage container were investigated. The study employed the volume of fluid, which is the phase change analysis model provided by ANSYS Fluent (ANSYS, Canonsburg, PA, USA), to investigate the sloshing phenomenon inside the liquefied hydrogen fuel tank. Considering the transient analysis time, two-dimensional simulation were carried out to examine the characteristics of the flow and thermal fields. The results indicated that the thermal flow characteristics and BOG phenomena inside the two-dimensional liquefied hydrogen storage container were significantly influenced by changes in gravity direction and hydrogen filling rate.

• 한국해양공학회지
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• 제4권2호
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• pp.262-262
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• 1990

In order to check the effect of dislocation behavior on creep rate in 12% Chromium steel, 14 samples of different compositions were examined by creep rupture test, and subgrain sizes, distribution of dislocations and precipitates were checked. And, authors reviewed the behaviors of dislocations, the formation and growth of subgrains and precipitates during creep. The results are as the following: 1) Creep rates calculated by .epsilon. over dot = .rho.bv show 10-15% higher values than actual data measured. However, authors conclude that the density and velocity of dislocations together with subgrain size are important factors governing deformation during creep in 12% chromium steel. 2) The values of the strength of obstacles in the mobility of dislocations are more clearly depended on the effective stress in the range of $10{\pm}5kgf/mm^{2}$ and increase with the increase of temperature. 3) Creep rates decrease with the smaller sizes of subgrains formed and can result in the longer creep rupture lives(hours). The smaller subgrains can be made by forming shorter free gliding distances of dislocations with very fine precipitates formed in the matrix during creep by applying proper alloy design. 4) Dislocation mobility gets hindered by precipitates occurring, which are coarsened by the softening process governed by diffusion during long time creep.

• 한국해양공학회지
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• 제4권2호
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• pp.112-120
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• 1990

In order to check the effect of dislocation behavior on creep rate in 12% Chromium steel, 14 samples of different compositions were examined by creep rupture test, and subgrain sizes, distribution of dislocations and precipitates were checked. And, authors reviewed the behaviors of dislocations, the formation and growth of subgrains and precipitates during creep. The results are as the following: 1) Creep rates calculated by .epsilon. over dot = .rho.bv show 10-15% higher values than actual data measured. However, authors conclude that the density and velocity of dislocations together with subgrain size are important factors governing deformation during creep in 12% chromium steel. 2) The values of the strength of obstacles in the mobility of dislocations are more clearly depended on the effective stress in the range of $10{\pm}5kgf/mm^{2}$ and increase with the increase of temperature. 3) Creep rates decrease with the smaller sizes of subgrains formed and can result in the longer creep rupture lives(hours). The smaller subgrains can be made by forming shorter free gliding distances of dislocations with very fine precipitates formed in the matrix during creep by applying proper alloy design. 4) Dislocation mobility gets hindered by precipitates occurring, which are coarsened by the softening process governed by diffusion during long time creep.

• 상하수도학회지
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• 제30권3호
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• pp.263-270
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• 2016

Recent Engineered nanoparticles were increasingly exposed to environmental system with the wide application and production of nanomaterials, concerns are increasing about their environmental risk to soil and groundwater system. In order to assess the transport behavior of silver nanoparticles (AgNPs), a saturated packed column experiments were examined. Inductively coupled plasma-mass spectrometry and a DLS detector was used for concentration and size measurement of AgNPs. The column experiment results showed that solution chemistry had a considerable temporal deposition of AgNPs on the porous media of solid glass beads. In column experiment, comparable mobility improvement of AgNPs were observed by changing solution chemistry conditions from salts (in both NaCl and $CaCl_2$ solutions) to DI conditions, but in much lower ionic strength (IS) with $CaCl_2$. Additionally, the fitted parameters with two-site kinetic attachment model form the experimental breakthrough curves (BTCs) were associated that the retention rates of the AgNPs aggregates were enhanced with increasing IS under both NaCl and $CaCl_2$ solutions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권11호
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• pp.5322-5342
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• 2016

In vehicle-to-vehicle (V2V) networks, where selfishness degrades node activity, countermeasures for collaboration enforcement must be provided to enable application of a sage and efficient network environment. Because vehicular networks feature both high mobility and various topologies, selfish behavior judgment and establishment of a stable routing protocol become intensely challenging. In this paper, a two-phase-based generous cooperative routing protocol (called GEC) is presented for V2V networks to provide resistance to selfishness. To detect selfish behaving vehicles, a packet forwarding watchdog and an average connection rate based on the multipath weight method are used, where evidence is gathered from different watchdogs. Then, multihop relay decisions are made using a generous cooperative algorithm based on game theory. Finally, through buffering of the multiple end-to-end paths and judicious choice of optimal cooperative routes, route maintenance phase is capable of dealing with congestion and rapidly exchanging traffic. Specifically, it is proved that the GEC is theoretically subgame perfect. Simulation results show that for V2V networks with inherently selfish nodes, the proposed method isolates uncooperative vehicles and is capable of accommodating both the mobility and congestion circumstances by facilitating information dissemination and reducing end-to-end delay.

• 한국염색가공학회지
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• 제11권5호
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• pp.44-54
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• 1999

Poly(ethylene 2,6-naphthalate), PEN, is a relatively well-known polymer used for engineering purposes. Naphthalene ring provides rigidity to the polymer backbone, thus, it elevated the glass transition temperature and enhanced mechanical properties. The structure and properties of PEN affect a processing conditions severely, and the high-thermal stability have been had a poor thermal processibility. Hence, the basic mechanism of solvent drawing, is very much the same as that of thermal drawing from glassy state since both involve the inducement of segmental mobility. The former achieves the goal by use of chemical energy, and the latter does so by use of thermal energy. Generally, the sorption of the solvent by the polymer has a plasticizing effect, and leads to a lowering of the glass transition temperature, $T_g$. In this paper, the dynamic viscoelasticity behavior in liquid-drawing process of an unoriented amorphous PEN films were investigated using Rheovibron. The results are as follows ： (1) For the drawing in silicone oil, the drawing below $T_g$. had $\alpha{2}$-dispersion due to an inhomogeneous taut structure. (2) For the drawing in water, the inhomogeneous taut structure reduced by the effect of plasticization even below $T_g$. (3) For the drawing in butanol, the only aliphatic segment in PEN have some molecular mobility but the mobility of the aromatic segment having naphthalene ring is nearly impossible. (4) For the drawing in dioxane/water mixing solvent, the solvent effect is complementary each other and accordingly the entire molecular conformation have stable state. (5) For the drawing in dioxane/butanol mixing solvent, the inhomogeneity of the taut structure and the aromatic segment increase with increasing the temperature and this tendencies correspond with that of the draw ratio.

• 자원환경지질
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• 제37권3호
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• pp.311-324
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• 2004

전라남도 보성강에 축조된 주암댐의 집수유역 내 하상퇴적물을 대상으로 중금속의 오염현황과 거동 특성을 알아보았다. 주암댐의 집수유역에는 많은 폐금속 및 탄광이 위치하고 있어 주암댐 호저퇴적물에 잠재적인 오염원으로 작용할 수 있다. 집수유역 내 하상퇴적물의 중금속 함량(Cr, Cu, Ni, Pb, Zn)은 매우 낮기 때문에 주암댐의 호저퇴적물에 영향을 줄 것으로 판단되지 않는다. 하지만 폐금속광산지역 내 하상퇴적물의 Pb 함량은 하류로 갈수록 증가하는 경향을 보여, Pb의 오염 확산이 우려된다. 폐금속광산의 환경을 고려한 강산성 조건의 용출실험결과, 하상퇴적물의 용출비로부터 결정된 중금속의 상대적 이동도는 Pb＞Zn=Cu＞Ni＞Cr으로서, Pb이 주암댐 호저퇴적물에 영향을 미치는 원소가 될 수 있음을 지시해준다. 한편 댐으로 유입한 퇴적물이 호저에 놓이게 되면(즉, 환원환경), Pb의 이동도가 비교적 높게 나타나 물-퇴적물 경계에서 Pb의 수중으로 재용출될 수 있다.

• 유통과학연구
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• 제13권12호
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• pp.5-11
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• 2015

Purpose - The purpose of this research is to investigate the influence of social status perception and interest in social issues on the authenticity perceived by consumers of the corporate social responsibility (CSR) activities of premium brands. Research design, data, and methodology - Behavioral experiments were performed to observe the impact of consumers' social status perception and interest in social issues on their perceived authenticity of CSR motivation related to premium brands and consumer behavior. Results - We found that the possibility of social mobility and the degree of individuals' interest in the environment and CSR enable them to reconsider the authenticity of CSR motivation, thereby having positive effects on purchase intention, willingness to recommend the product, and brand value. This research also showed that proactive customers who seek to move up the social ladder have a stronger interest in social issues such as the environment or CSR. Conclusions - Our research suggests that when conducting a consumer segmentation analysis for the launch of CSR products (products released for CSR), a positive mind-set toward social mobility serves as an effective criterion.