• International journal of advanced smart convergence
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• 제11권2호
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• pp.205-210
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• 2022

To achieve the higher network capacity and mass connectivity in the forthcoming mobile network, revolutionary technologies have been considered. Recently, an upper bound on capacity of intelligent reflecting surface (IRS) transmissions towards the sixth generation (6G) mobile systems has been proposed. In this paper, we consider a tighter upper bound on capacity of IRS transmissions than the existing upper bound. First, using integration by parts, we derive an upper bound on capacity of IRS transmissions under Rician fading channels and a Rayleigh fading channel. Then, we show numerically that the proposed upper bound is closer to Monte Carlo simulations than the existing upper bound. Furthermore, we also demonstrate that the bounding error of the proposed upper bound is much smaller than that of the existing upper bound, and the superiority of the proposed upper bound over the existing upper bound becomes more significant as the signal-to-noise ratio (SNR) increases.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.570-577
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• 2003

The importance of cornified envelope (CE)-bound lipids to epidermal barrier function is increasingly being recognized. In the present study, we intentionally damaged the cornified layer of hairless mice by ultraviolet irradiation and sodium dodecyl sulfate (SDS) treatment, and assessed the changes in epidermal barrier function by measuring Trans Epidermal Water Loss (TEWL). We also measured changes in the amount of CE-bound lipids using thin layer chromatography (TLC). The results showed that both treatments increased TEWL and decreased CE-bound lipids (omega-hydroxy cerami de and omega-hydroxy acid). In addition, investigation of the chronological changes in TEWL revealed an inverse relationship between TEWL and CE-bound lipids, and a correlation between CE-bound lipids and epidermal barrier function. We then measured the amount of CE-bound lipids in the cheek and the medial side of the upper arm in humans. The results showed that because the cheek receives external stimulation on a daily basis, the amount of CE-bound lipids was significantly lower, while the level of TEWL was higher. These observations, together with those from the animal study, indicate that CE-bound lipids are related to epidermal barrier function.

• Journal of Nutrition and Health
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• 제27권8호
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• pp.828-836
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• 1994

A low level exposure experiment was conducted on growing rats to investigate the accumulation and organ distribution of protein bound cadmium compared with cadmium chloride. Male Sprague-Dawley rats were fed for 21days with one of the semisynthetic diets, which contains cadmium as either bovine liver- or kidney meal bound cadmium, cadmium chloride with uncontaminated liver meal or cadmium chloride without organ meal, in the levels of ca. 0.5, 1 and 1.5mg/kg diet, respectively. After 21days of exposure cadmium was accumulated in liver, kidney and gastrointestinal tracts depending upon cadmium levels in diet. Inspite of very low cadmium accumulation in whole blood, it tends also to increase with dietary cadmium levels. The blood cadmium concentration of animals fed organ meal containing diets was about 4-7 fold higher than that without organ meal, regardless of cadmium was intrinsically bound to protein or not. However, significant effects of organ protein on cadmium accumulation in liver, kidney and digestive tracts were not detectable, when cadmium was supplemented as cadmium chloride. On the other hands, animals fed diet containing ca. 1.5mg Cd/kg as organ bound cadmium retained more cadmium in liver, kidney and digestive tracts compared to cadmium chloride with organ meal, whereby the increase of cadmium concentration in kidney was greater then in liver. However, when the concentration of protein bound cadmium was<1mg/kg diet, organ bound cadmium was not significantly different from cadmium chloride in bioavailability and organ distribution. From this result it is suggested that the intestinal absorption of protein bound cadmium is influenced of the amount of cadmium bound in protein. When cadmium concentration in protein is relatively low, protein bound cadmium seems to be absorbed in the same way as cadmium ions are absorbed. However, when the concentration is high, at least a small amount of intact protein bound cadmium could be absorbed and accumulated selectively in kidney.

• Geomechanics and Engineering
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• 제27권6호
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• pp.573-582
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• 2021

From the effect of bound water, this study aims to seek the potential reasons for difference of mechanical experiment results of subgrades soils. To attain the comparatively test condition of bound water, dry forming (DF) and wet forming (WF) were used in the specimen forming process before testing, series of laboratory tests, i.e., CBR tests, direct shear tests and compaction tests. The measured optimal moisture contents, maximum dry densities, CBR, cohesion c, and internal friction angle 𝜑 were given contrastive analysis. Then to detect the adsorptive bound water in the subgrade soils, the thermal gravimetric and differential scanning calorimetry (TG-DSC) test were employed under different heating rates. The free water, loosely bound water and tightly bound water in soils were qualitatively and quantitatively analyzed. It was found that due to the different dehydration mechanics, the lost bound water in DF and WF process show their own characteristics. This may lead to the different mechanical properties of tested soils. The clayey particles have a great influence on the bound water adsorbed ability of subgrade soils. The more the clay content, the greater the difference of mechanical properties tested between the two forming methods. Moreover, in highway construction of southern China, the wet forming method is recommended for its higher authenticity in simulating the subgrade filed humidity.

• 한국토양비료학회지
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• 제41권3호
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• pp.184-189
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• 2008

To assess the relationship between Cd fraction in paddy soils and Cd in polished rice, soils and rice were analyzed at the 3 Cd contaminated paddy fields near closed mines. Major Cd fractions of A field were organically bound (62.6%) and Fe-Mn oxide bound (25.3%) forms. In case of B field, major Cd fractions of B1 field were carbonate bound (46.3%) and Fe-Mn oxide bound (31.6%) form whereas B2 field were residual (54.3%) and carbonate bound (21.8%) form, respectively. It showed a huge difference of Cd fraction each other. 0.1M HCl extractable Cd in soil was positively correlated with Cd in rice. Specially, the ratios of 0.1M HCl extractable Cd against total Cd content in soils were 13.7%, 2.6%, and 0.45% in A, B1, and B2 fields, respectively. These ratio were largely affected with Cd uptake to rice grain. Also, exchangable, Fe-Mn oxide bound, and carbonate bound form, which are partially bioavailable Cd fraction to the plant, were positively correlated with Cd in rice while organically bound and residual form was not correlated. Multiple regression equation was developed with Rice Cd = -0.02861 + 0.07456 FR 1(exchangeable) + 0.00252 FR 2(carbonate bound) + 0.001075 FR 3(Fe Mn oxide bound) - 0.00095 FR 4(organically bound) - 0.00348 FR 5(residual) ($R^2=0.7893^{***}$) considering Cd fraction in soils.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.556-558
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• 2008

Secure broadcasting is requirement for payment of TV systems, government or company. Hierarchical key management for access control provides efficient key management in those environment. Also, time-bound hierarchical key management technique generates different keys in each time period. In 2004, Tzeng proposed a time-bound cryptgraphic key assignment scheme for access control in a hierarchy and in 2008, Bertino et al proposed an efficient time-bound hierarchical key management scheme for secure broadcasting. Tzeng's scheme and Bertino et al's scheme are organized in different environment and primitive. In this paper, we analysis above two time-bound hierarchical key management scheme.

• 대한수학회보
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• 제54권2호
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• pp.507-519
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• 2017

We present an upper bound on the Cheeger constant of a distance-regular graph. Recently, the authors found an upper bound on the Cheeger constant of distance-regular graph under a certain restriction in their previous work. Our new bound in the current paper is much better than the previous bound, and it is a general bound with no restriction. We point out that our bound is explicitly computable by using the valencies and the intersection matrix of a distance-regular graph. As a major tool, we use the discrete Green's function, which is defined as the inverse of ${\beta}$-Laplacian for some positive real number ${\beta}$. We present some examples of distance-regular graphs, where we compute our upper bound on their Cheeger constants.

• 한국CDE학회논문집
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• 제15권1호
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• pp.24-32
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• 2010

This paper introduces a B-spline based branch & bound algorithm for global optimization. The branch & bound is a well-known algorithm paradigm for global optimization, of which key components are the subdivision scheme and the bound calculation scheme. For this, we consider the B-spline hypervolume to approximate an objective function defined in a design space. This model enables us to subdivide the design space, and to compute the upper & lower bound of each subspace where the bound calculation is based on the LHS sampling points. We also describe a search tree to represent the searching process for optimal solution, and explain iteration steps and some conditions necessary to carry out the algorithm. Finally, the performance of the proposed algorithm is examined on some test problems which would cover most difficulties faced in global optimization area. It shows that the proposed algorithm is complete algorithm not using heuristics, provides an approximate global solution within prescribed tolerances, and has the good possibility for large scale NP-hard optimization.

• 생태와환경
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• 제48권3호
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• pp.168-175
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• 2015

추계 대청호 퇴적물에서 가장 많이 존재하는 인의 형태는 환원환경이 되면 용출될 수 있는 Al-bound와 Fe-bound 인으로 나타났다. 총인, Al-bound와 Fe-bound 인은 가두리 양식장이 분포하였던 회남 지점과 대청댐 앞에서 높게 나타났다. 그 이유는 가두리 양식장 같은 인위적인 활동보다는 세립질 퇴적물의 이동과 연관이 있는 것으로 판단된다. 대청호 퇴적인의 농도는 그 어느 존재형태도 타 인공호수에 비해 높지 않았다. 그러나 보다 더 객관적인 비교를 위해서 존재형태별 연속추출법을 표준화해야 할 것이다.

• 농약과학회지
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• 제2권1호
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• pp.70-78
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• 1998

토양에 살포된 양이온성 농약인 paraquat가 점토광물, 유기물 및 토양 시료에서의 흡착량, 흡착 특성, 흡착 형태 및 탈착간의 상호관계에 관하여 조사하였다. 점토광물에 의한 paraquat의 흡착 시간은 유기물 및 토양 시료에 비하여 빠르게 나타났다. 팽창형 점토광물인 montmorillonite에 의한 흡착은 총흡착량 뿐만 아니라 CEC에 대한 흡착 비율에서도 다른 흡착제에 비하여 높게 나타났다. Humic acid와 fulvic acid는 점토광물인 kaolinite와 토양 시료보다도 많은 양의 paraquat을 흡착하였다. 토양 시료에 의한 흡착은 CEC의 약 21% 정도로 점토광물에 비하여 25-50% 수준인 것으로 나타났다. Paraquat의 흡착 형태별 분포 시험에서 점토광물 및 토양 시료에서는 tightly bound type의 비율이 가장 높았으나, humic acid및 fulvic acid에서는 loosely bound type의 비율이 높게 나타났다. 유기물을 제거한 토양 시료의 paraquat 흡착량은 유기물을 제거하지 않은 토양의 85.1-95.5% 정도이며, unbound 및 loosely bound type의 비율이 감소한 반면 tightly bound type의 비율이 증가하였다. 용액중에 경쟁 양이온이 공존하는 경우, paraquat의 흡착은 유기물에서 약 35%정도 감소하였으나 montmorillonite에서는 감소 효과가 나타나지 않았으며, 경쟁 양이온의 종류에 따른 차이는 나타나지 않았다. 흡착제가 양이온으로 포화되어 있는 경우 paraquat의 흡착은 유기물에서 75% 정도, 토양 시료에서 65% 정도 감소하였으나 montmorillonite에서는 약 30% 정도만이 감소하였다. 흡착 형태에 따른 paraquat의 탈착 시험에서 tightly bound type은 흡착제의 종류에 관계없이 pH 조절, 초음파처리, 양이온의 첨가에 의하여서는 탈착되지 않았다. Loosely bound type의 paraquat는 흡착제의 종류 및 탈착방법에 따라 탈착율이 다르게 나타났으나, 양이온 첨가나 pH조절과 같은 화학적 변화 또는 초음파처리와 같은 물리적 충격에 의하여 탈착될 수 있는 것으로 나타났다.