• International Journal of Internet, Broadcasting and Communication
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• 제13권3호
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• pp.17-24
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• 2021

Recently, a lossless non-orthogonal multiple access (NOMA) implementation without successive interference cancellation (SIC) has been proposed in the literature of NOMA. This lossless non-SIC NOMA was achieved via correlated superposition coding (CSC), in contrast to conventional independent superposition coding (ISC). However, only the achievable data rates for CSC NOMA were investigated. Thus, this paper proposes a practical CSC NOMA scheme under Rayleigh fading channel environments. First, we design the practical CSC NOMA scheme, namely quadrature correlated superposition modulation (CSM) NOMA, without channel coding, i.e., uncoded systems. In addition, we calculate the symbol error rates (SERs) for this quadrature CSM NOMA scheme. Then, simulations demonstrate that for the weak channel gain's user, the SER performance of the proposed quadrature CSM NOMA is shown to be improved greatly, compared to that of the conventional quadrature amplitude modulation (QAM) NOMA, whereas for the strong channel gain's user, the SER performance of the proposed quadrature CSM NOMA degrades a little, compared to that of the conventional QAM NOMA. As a result, the proposed quadrature CSM NOMA scheme could be considered as a practical NOMA scheme for CSC NOMA schemes toward the fifth-generation (5G) and next generation communications.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.73-84
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• 2003

Skin aging process on pre-menopausal women is a problem that needs to be prevented as early as possible. The decrease of oestrogen level which is one of the intrinsic factors of the skin aging process will affect the skin biological process, due to oestrogen receptors on the skin. A number of researches conducted on pre-menopausal women with the allocation of oestrogen hormone resulted in delaying the skin aging process. The administration of soy isoflavon, a phytoestrogen found in daily food, on pre-menopausal women is hoped to be able to prevent skin aging process, even clinically or molecular biologically. This research aims to explain the benefit of administering of soy isoflavon on skin aging process. The design of the research is randomised controlled trial (RCT). As many as 60 pre-menopausal women were collected with simple random sampling method. Soy isoflavon is an independent variable, while skin aging process is a dependent variable assessed from the hydration, sebum level, average roughness, depth of wrinkles, skin clarity, length of the telomere. Analysis was conducted using t and MANDVA tests and.the result showed a significance (F = 10,439; p = 0,001) over the allocation of soy isoflavon to the whole variable dependent, including the telomere length and the skin hydration, meant that allocation of soy isoflavon could delay skin aging process.

• International journal of advanced smart convergence
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• 제10권3호
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• pp.17-25
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• 2021

As a new paradigm in non-orthogonal multiple access (NOMA), correlated superposition coding (CSC) has gained an attention in the literature of NOMA, in contrast to standard independent superposition coding (ISC). In the conventional 3-user CSC scheme, it has been reported that the average allocated power can be reduced, owing to an introduced correlation between transmitted signals. Thus, this paper proposes a 3-user cross CSC scheme with purely-imaginary correlation coefficients. First, we derive the achievable data rates of the proposed 3-user cross CSC scheme, for each of the three users. Then, simulations demonstrate that for the proposed 3-user cross CSC scheme, the achievable data rates of the first and second users increase greatly and slightly, respectively, whereas the achievable data rate of the third user decreases little, compared to those of the conventional 3-user CSC scheme. In addition, we also show that the sum rate of the three users of the proposed 3-user cross CSC scheme is much larger than that of the three users of the conventional 3-user CSC scheme. As a result, the proposed 3-user cross CSC scheme could be a solution to the problem of the reduction of the average allocated total power in the conventional 3-user CSC scheme toward the fifth-generation (5G) NOMA mobile networks.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.69.2-69.2
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• 2010

Recently, bulk hetero-junction cells have been extensively studied by many researchers. Most of these cells were fabricated by spin coater. However, the spin coating process is not favorable to the large-scaled industry because it is not compatible with roll-to-roll process. One of the alternative methods is Doctor blading. In this study, we fabricated large OPV cells having total area of $100cm^2$. The buffer layer was Poly-(3,4-ethylenedioxythiophene) : poly-(styrenesulfonate) aqueous dispersion (PEDOT:PSS) and the active material is poly (3-hexythiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blend in the solvent of Chlorobenzene. All of the organic layers were coated by dragging the blade with a speed of 5~20 mm/s on the stage with a temperature of $50^{\circ}C$. As-bladed PEDOT:PSS layer was baked at $120^{\circ}C$ for 10 minutes to eliminate the water. The cell structure is patterned ITO substrate/PEDOT:PSS/P3HT:PCBM/LiF/Al. The topmost electrode, LiF/Al, was deposited by thermal evaporation. After depositing electrode, and the cell was annealed at $150^{\circ}C$ for 30 minutes. The measured ISC, VOC, fill factor, and PCE were 2.95 A, 5.86 V, 0.32, and 0.78%, respectively. PCE was quite low but the large active area could be obtained successfully.

• 한국전기전자재료학회논문지
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• 제23권11호
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• pp.901-905
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• 2010

PV module has many power loss factors, and series resistance is the most important elements of them. It is therefore easy to expect the partial shading decrease the lifetime of the semiconductor depletion layer in thin film PV module. Different shading losses could be related with the hot spot which is critical in expecting the reliability issue. In this paper we have modelled the series resistance of the PV module with both different direction of the cell line and shading area of the panel. From the results, thin film a-Si PV module has shown different properties by shading direction.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.252-256
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• 2008

Photovoltaic (PV) modules output changes noticeable with variations in temperature and irradiance. In general it is has been shown that a $1^{\circ}C$ increase in temperature results in a 0.5% drop in output. In this paper, seven PV module types are analyzed for variation in temperature and irradiance, and the resulting output characteristics examined. The 7 modules types utilized are as follows; 3 poly crystalline modules, 2 single crystalline modules, 1 back contact single crystalline module and 1 HIT module. 3 groups of experiments are then conducted on the modules; tests with varying irradiance values, tests with module temperature varying under $25^{\circ}C$ and tests with module temperature varying over $25^{\circ}C$. The experiments results show that as temperature rises the follow is observed; Pmax decreases by 0.6%, Voc decreases by about 0.4%, and Isc increasing by between 0.03%${\sim}$0.08%. In addition, an irradiance decrease of 100 w/m2 translates into a 10% drop in Pmax.

• 대한기계학회논문집B
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• 제32권11호
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• pp.884-890
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• 2008

Many researches have been carried out to reduce the emission levels and lower the fuel consumption in SI engines. Recently electronically controlled injection system is widely adapted to a passenger car to achieve these goals. Throttle body is also an important factor which influences on the emissions and engine power. In this study we redesigned a throttle body and conducted an experimental study to see the effects on engine performance and emission characteristics. We could find that idle speed control(ISC) showed stable operation characteristics as the cooling water temperature varied. And CO and HC emissions also satisfied the regulation limit.

• Journal of Welding and Joining
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• 제17권5호
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• pp.61-68
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• 1999

For the last two decades, waveform control techniques have been successively developed and applied for the inverter welding machines resulting in the substantial reduction of spatter generated in CO₂ welding. One of the constituents commonly involved in those techniques is to delay the instant of current increase to some extent after the initiation of short-circuiting. Although this technique has been known to be quite effective in reducing the spatter generation through the suppression of is instantaneous short circuiting, the delay time necessary for minimum spatter has not been clearly understood. In this study, the control system for varying the delay time was constructed so that the spatter generation rates could be measured over a wide range of delay time, 0.29-2.0 msec. As a result of this study, it was demonstrated that spatter generation rate(SGR) sharply decreased at delay time of 0.6 msec and longer accompanied with the change in characteristics of short circuit mode from the instantaneous short-circuiting(ISC) dominant to normal short-circuiting(NSC) dominant. Another feature that have been found in current waveform of over 0.6msec was the creation of current pulse right after the arc reignition stage. Because of this current pulses weld pool oscillated in wave-like fashion and it looks like to play an important role in developing short circuiting between electrode and weld pool.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.3-4
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• 2008

Photovoltaic module consists of serially connected solar cell which has low voltage characteristics. But, the other way, the whole current flow of PV module is restricted by lowest current of one solar cell. For the experiment, we make PV module composing the solar cells that have short circuit current difference of 0%, 1%, 3% and 5%. Using Light I-V and Dark I-V measurements, electrical characteristic parameters like Isc(short-circuit current), Voc(open-circuit voltage), Rs(series resistance), Rsh(shunt resistance) are analyzed. PV module of low current characteristics has electrical stress from other modules. And, such a module has a tendency of hot-spot suffering which leads degradation.

• Asia pacific journal of information systems
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• 제31권2호
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• pp.236-256
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• 2021

Online financial technology products are an important consumer finance innovation. While a large body of previous research has focused on initial adoption and consumer willingness to use these products, little research explores the continued use of these products beyond the initial adoption phase. In particular, special attention should be paid to how users' trust and perceptions of privacy and security affect continued use behavior. This paper integrates the expectation confirmation model of information system continuance (ECM-ISC), the information system success model (ISSM) and the security and trust literatures to investigate continued use of online financial technology. To test the research model, we collected 398 valid questionnaires from Ant Credit Pay users. The research results show that system and service quality positively impact users' expectation confirmation, while information quality has no significant impact. Expectation confirmation and perceived usefulness positively affect user satisfaction. Moreover, the user's perception of privacy and security plays a vital role in user satisfaction. Satisfaction and perceived trust jointly promote users' continuance behaviors. Findings of this study indicates the importance of the information system success factors and security factors due to their influence on the continued use of Fintech products. This conclusion has implications for enterprises in improving the product qualities and enhancing the degree of security to meet user needs.