• Geomechanics and Engineering
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• 제25권4호
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• pp.303-315
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• 2021

A rigorous and generic similarity solution is developed for assessment of the undrained expansion responses of a cylindrical cavity expansion in K₀-consolidated anisotropic soils. A K₀-consolidated anisotropic modified Cam-clay (K₀-AMCC) model that can represent the initial stress anisotropy and the effects of stress-induced anisotropy is used to model the soil behaviors during cavity expansion. All the seven basic unknowns, the three stress components, the pore water pressure, the particle velocity, the specific volume and the hardening parameter, are reduced to the functions of a dimensionless radial coordinate and are taken as coupled variables to formulate the problem. The governing equations are formulated by making use of the equilibrium equation, the constitutive equation, the consistency condition, the continuity condition and the undrained condition, which are then solved as an initial value problem. The proposed rigorous similarity solution is compared with some well-documented rigorous solutions to validate the solution and to highlight the special expansion responses in anisotropic soils. The results reveal that the present solution can yield more predictions for cavity expansion problems in soils with initial anisotropic stresses.

• 한국치위생학회지
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• 제15권1호
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• pp.91-99
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• 2015

Objectives: The purpose of the study was to investigate the relationship between internet addiction and health in dental hygiene students. Methods: A self-reported questionnaire was completed by 216 dental hygiene students in Daegu from June 9 to 13, 2014. Data were analyzed by descriptive statistics, t-test, and ANOVA using SAS 9.2 program. The instruments included Korean internet addiction scale(K scale) and Korean version of the general health questionnaire. General characteristics consisted of grade, religion, residential types, economic condition, place of internet use, duration, purpose, and time of use. Physical characteristics consisted of subjective physical condition, smoking, alcohol drinking, exercise above twice per week, musculoskeletal disease, and location of physical symptoms. Psychiatric scale and 6 questions of physical characteristics were consulted by the statistician of preventive medicine department. Results: Internet users over 4 hours manifested the poor mental health, while those who uses internet under 2 hours showed good mental health(F = 1.41, p < 0.01). The students having good physical condition showed better mental health than those with poor physical condition(t = -2.81, p < 0.01). The students exercising at least twice a week showed better mental health than those who do not exercise(t = -3.10, p < 0.01). Those who having musculoskeletal symptoms showed higher index of internet addiction score than those who do not(t = 4.21, p < 0.01). Those who have no musculoskeletal symptoms tended to have better mental health than those who have musculoskeletal symptoms(t = 2.28, p < 0.05). The variables correlated to mental health were internet addiction, subjective physical condition, and exercise at least twice a week. The severity level of internet addiction leads to poor mental health(r = 0.26, p < 0.001). Conclusions: Internet addiction is closely related to mental health. So the students must know the danger of internet addiction. Proper health education is necessary for the prevention of addiction symptoms.

• Journal of Oral Medicine and Pain
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• 제30권4호
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• pp.427-432
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• 2005

본 연구는 구강안면통증 환자의 음성적 특징과 청각 환경에 따른 음성적 변화를 살펴보기 위한 것이다. 구강안면통증 환자 29명과 정상인 31명을 대상으로 그들의 일반 음성과 청각 조건(소음, 음악)에서의 음성 파라미터들을 비교 분석하여 다음과 같은 결론을 얻을 수 있었다. 1. 구강안면통증 환자는 정상인의 음성과 비교해 낮은 F0(Hz) 값과 높은 jitter(%), shimmer(%)값을 가져 정상인에 비해 낮고 불안정한 음성 특징(feature)을 나타내었다. 2. 구강안면통증 환자의 음성은 소음 환경과 비교해 음악 환경에서 낮은 F0(Hz)값과 shimmer(%)값을 가져 보다 이완되고 안정된 음성 특징을 나타내었다. 3. 정상인의 음성은 소음 환경에서 높은 F0(Hz)값을 가졌으나 음악, 소음 환경에 따른 특징적인 차이를 나타내지 않았다. 이상의 결과를 통해 구강안면통증 환자는 정상인의 음성과 비교해 특징적인 차이를 보였으며 외부적인 청각 환경에도 다른 반응 양상을 나타내었다. 따라서 구강안면통증 환자들의 기능적 장애를 보다 효율적으로 치료하기 위해서는 음악과 같은 긍정적인 정서 환경이 제공되어야 할 것으로 사료된다.

• 동의생리병리학회지
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• 제20권1호
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• pp.115-124
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• 2006

The purpose of this study is to investigate the relationships between the biological base of coping strategy and the different constitutions. First of all, subjects were divided in to 3 groups dy Questionnaire for the Sasang Constitution Classification II and Yin-Yang Property Analysis. Then each group was assigned into two experimental coping conditions, active and passive condition, in turn. The SDNN(The Standard Deviation of the NN Intervals) of HRV(Heart rate variability) index was estimated from two conditions after giving a aversive pain stimulus. The results of the study were as follows 1. The interaction between constitution and coping condition is significant(p<0.05). 2. The SDNNs of Shaoyangren are higher than those of Taiyinren under passive condition but it was opposite under active condition(p<0.05). 3. The main effect of constitution is also significant but that of coping condition is not significant. 4. Thee Shaoyangren is higher than Shaoyinren in multiple comparisons(p<0.05). 5. The interaction between Yin-Yang constitution and coping condition is significant and the main effect of only constitution is significant(p<0.05). According to these results, different constitution can respond differently to coping condition and It is highly related to biological mechanism associated with two basic coping strategies.

• 한국주조공학회지
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• 제26권6호
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• pp.249-257
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• 2006

The effects of alloying element and the condition of heat-treatment on the strength of squeeze-cast Al-3.0 wt%Si alloy were investigated. The strength of the alloy without grain refinement was increased with increase Cu content upto 3.0 wt% and rather decreased beyond that. The tensile strength of the alloy with grain refinement increased with Cu content upto 3.0 wt% and not changed beyond that. The strength of the alloy without grain refinement increased with the Mg content. The tensile strength with grain refinement increased with the Mg content upto 0.50 wt% and then decreased beyond that. The strength of the grain refined alloy increased by individual and simultaneous additions of Cu and Mg and the maximum strength was obtained with Al-3.0 wt%Si-4.5 wt%Cu-0.50 wt%Mg alloy. The optimum heat-treatment condition for this alloy was obtained.

• 한국물환경학회지
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• 제23권4호
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• pp.474-481
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• 2007

With population growth, industrialization, and urbanization within the watershed, the hydrologic response changed dramatically, resulting in increases in peak flow with lesser time to peak and total runoff with shortened time of concentration. Infiltration is directly affected by initial soil moisture condition, which is a key element to determine runoff. Influence of the initial soil moisture condition on hydrograph analysis should be evaluated to assess land use change impacts on runoff and non-point source pollution characteristics. The Long-Term Hydrologic Impact Assessment (L-THIA) model has been widely used for the estimation of the direct runoff worldwide. The L-THIA model was applied to the Little Eagle Creek (LEC) watershed and Its estimated direct runoff values were compared with the BFLOW filtered direct runoff values by other researchers. The $R^2$ value Was 0.68 and the Nash-Sutcliffe coefficient value was 0.64. Also, the L-THIA estimates were compared with those separated using optimized $BFI_{max}$ value for the Eckhardt filter. The $R^2$ value and the Nash-Sutcliffe coefficient value were 0.66 and 0.63, respectively. Although these higher statistics could indicate that the L-THIA model is good in estimating the direct runoff reasonably well, the Antecedent Moisture Condition (AMC) was not adjusted in that study, which might be responsible for mismatches in peak flow between the L-THIA estimated and the measured peak values. In this study, the L-THIA model was run with AMC adjustment for direct runoff estimation. The $R^2$ value was 0.80 and the Nash-Sutcliffe coefficient value was 0.78 for the comparison of L-THIA simulated direct runoff with the filtered direct runoff. However there was 42.44% differences in the L-THIA estimated direct runoff and filtered direct runoff. This can be explained in that about 80% of the simulation period is classified as 'AMC I' condition, which caused lower CN values and lower direct runoff estimation. Thus, the coefficients of the equation to adjust CN II to CN I and CN III depending on AMC condition were modified to minimize adjustments impacts on runoff estimation. The $R^2$ and the Nash-Sutcliffe coefficient values increase, 0.80 and 0.80 respectively. The difference in the estimated and filtered direct runoff decreased from 42.44% to 7.99%. The results obtained in this study indicate the AMC needs to be considered for accurate direct runoff estimation using the L-THIA model. Also, more researches are needed for realistic adjustment of the AMC in the L-THIA model.

• International journal of advanced smart convergence
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• 제3권1호
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• pp.20-24
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• 2014

To compare body signal, was designed the F-B function system on the body movement for the comfortable state. To detect subject of the normal state, was decided on the base of physical signal in the body movement. There are to detect the condition of Vision, Vestibular, Somatosensory and CNS. Vision condition was verified a variation of greater average (Vi-${\Phi}_{AVG-AVG}$) was presented slightly greater at $17.424{\pm}9.65$ unit. Vestibular condition was identified a variation of slightly greater average (Ve-${\Phi}_{AVG-AVG}$) was presented at $9.068{\pm}1.478$ unit. Somatosensory condition was checked a variation of smaller average (So-${\Phi}_{AVG-AVG}$) was presented slightly smaller at $2.79{\pm}0.419$ unit. CNS condition was confirmed a variation of diminutive smaller average (C-${\Phi}_{AVG-AVG}$) was presented slightly larger at $0.557{\pm}0.153$ unit. As the model depends on the F-B function system of body movement, average values of these perturbation were computed F-B function comparison data. These systems will be to infer a data algorithm and a data signal processing system for the evaluation of the stability.

• Journal of Plant Biotechnology
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• 제30권1호
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• pp.53-58
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• 2003

여러가지 생장조절제를 첨가한 MS배지에 참나리의 기내배양 소인편과 실생인편을 치상하여 재분화 과정을 알아보았다. 소인편의 부정아 발생은 BAP 1.0mg/L와 NAA 0.1 mg/L을 혼합 처리한 MS배지에서 4주간 배양했을 때 가장 왕성하게 일어났으며, 실생인편의 부정아 발생률은 BAP 0.5mg/L와 NAA 0.1 mg/L에서 4주간 암배양했을 때 가장 높았다. 소인편의 캘러스 발생은 BAP 0.1 mg/L와 2,4-D 1.0 mg/L 혼합 처리구에서 가장 높았다. 또한. 캘러스의 재분화는 NAA 0.5 mg/L와 BAP 0.1 mg/L를 혼합 처리한 MS배지에서 8주간 명배양했을 때 가장 높았다. 뿌리는 MS배지에서 쉽게 발달되었으며, 8주 후 굵고 긴 뿌리를 갖춘 완전한 재분화 식물체로 성장하여 화분에 이식하였다. 참나리의 재분화 전, 후의 염색체 수는 모두 2n=24로서 조직배양에 의한 염색체수의 변화가 없음을 확인하였다.

• 대한수학회논문집
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• 제14권2호
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• pp.337-352
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• 1999

In this paper we find a geometric condition for the weaker principle of spatial averaging (PSA) for a class of polyhedral domains. Let \ulcorner be a polyhedron in R\ulcorner, n$\leq$3. If all dihedral angles of \ulcorner are submultiples of $\pi$, then there exists a parallelopiped \ulcorner generated by n linearily independent vectors {\ulcorner}\ulcorner in R\ulcorner containing \ulcorner so that solutions of $\Delta$u+λu=0 in \ulcorner with either the boundary condition u=0 or ∂u/∂n=0 are expressed by linear combinations of those of $\Delta$u+λn=0 in \ulcorner with periodic boundary condition. Moreover, if {\ulcorner}\ulcorner satisfies rational condition, we guarantee the weaker PSA for the domain \ulcorner.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.707-714
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• 2004

How to improve the cell culture method on scaffolds is important in the tissue engineering fileld. In this study, we optimized seeding and culture methods to vascular smooth muscle cells (VSMCs) on biodegradable polymer scaffold. The primary culture of VSMCs obtained from canine external jugular vein was accomplished by applying the explant-derived method. The primary cultured VSMCs were seeded into scaffolds and then cultured by using various different methods; static or dynamic seeding, static or dynamic culture. The difference in proliferative response of VSMCs was analyzed with an alamar blue assay. Cell-polymer construct was examined by histochemical method and scanning electron microscopy. Mesh type scaffold ($10 \times 10 \times0.4 mm$) was made of polyglycolic acid (PGA) suture thread. The PGA mesh type scaffold was 45% in porosity, and 0.03 g in weight. The primary cultured VSMCs were confirmed with immunohistochemical staining using monoclonal anti-$\alpha$-smooth muscle actin. The density and distribution of proliferated VSMCs within the scaffold and cellular adherence on the surface of the scaffold showed better results in the static seeding condition than in the dynamic condition. Under the same condition of seeding method as the static condition, the dynamic culture condition showed enhanced proliferation rates of the VSMCs when compared to the static culture condition. In conclusion, to improve the VSMCs proliferation in vitro, static seeding is better than the dynamic condition. In the culture condition, however, culture under the dynamic status is better than the static condition. This was a pilot study to manufacture artificial vascular vessel by tissue engineering.