Prediction of Soluble-Solid Content in Citrus Fruit Using Visible-Near-Infrared Hyperspectral Imaging Based on Effective-Wavelength Selection Algorithm.

Citrus fruits were sorted based on external qualities, such as size, weight, and color, and internal qualities, such as soluble solid content (SSC), acidity, and firmness. Visible and near-infrared (VNIR) hyperspectral imaging techniques were used as rapid and nondestructive techniques for determining the internal quality of fruits. The applicability of the VNIR hyperspectral imaging technique for predicting the SSC in citrus fruits was evaluated in this study. A VNIR hyperspectral imaging system with a wavelength range of 400-1000 nm and 100 W light source was used to acquire hyperspectral images from citrus fruits in two orientations (i.e., stem and calyx ends). The SSC prediction model was developed using partial least-squares regression (PLSR). Spectrum preprocessing, effective wavelength selection through competitive adaptive reweighted sampling (CARS), and outlier detection were used to improve the model performance. The performance of each model was evaluated using the coefficient of determination (R2) and root mean square error (RMSE). In the present study, the PLSR model was developed using only a citrus cultivar. The SSC prediction CARS-PLSR model with outliers removed exhibited R2 and RMSE values of approximatively 0.75 and 0.56 °Brix, respectively. The results of this study are expected to be useful in similar fields such as agricultural and food post-harvest management, as well as in the development of an online system for determining the SSC of citrus fruits.

Performance Improvement of Partial Least Squares Regression Soluble Solid Content Prediction Model Based on Adjusting Distance between Light Source and Spectral Sensor according to Apple Size.

Apples are widely cultivated in the Republic of Korea and are preferred by consumers for their sweetness. Soluble solid content (SSC) is measured non-destructively using near-infrared (NIR) spectroscopy; however, the SSC measurement error increases with the change in apple size since the distance between the light source and the near-infrared sensor is fixed. In this study, spectral characteristics caused by the differences in apple size were investigated. An optimal SSC prediction model applying partial least squares regression (PLSR) to three measurement conditions based on apple size was developed. The three optimal measurement conditions under which the Vis/NIR spectrum is less affected by six apple size levels (Levels I-VI) were selected. The distance from the apple center to the light source and that to the sensor were 125 and 75 mm (Distance 1), 123 and 75 mm (Distance 2), and 135 and 80 mm (Distance 3). The PLSR model applying multiplicative scatter correction pretreatment under Distance 3 measurement conditions showed the best performance for Level IV-sized apples (Rpre2 = 0.91, RMSEP = 0.508 °Brix). This study shows the possibility of improving the SSC prediction performance of apples by adjusting the distance between the light source and the NIR sensor according to fruit size.

Performance Comparison of Tungsten-Halogen Light and Phosphor-Converted NIR LED in Soluble Solid Content Estimation of Apple.

A Tungsten-Halogen (TH) lamp is the most popular light source in NIR spectroscopy and hyperspectral imaging, which requires a warm-up to reach very high temperatures of up to 250 °C and take a long time for radiation stabilization. Consequently, it has a large enough volume to enable heat dissipation to prevent the thermal runaway of the electric circuit and turn out its power efficiency very low. These are major barriers for miniaturizing spectral systems and hyperspectral imaging devices. However, TH lamps can be replaced by pc-NIR LEDs in order to avoid high temperature and large volume. We compared the spectral emission of the available commercial pc-NIR LEDs under the same condition. As a replacement for the TH lamp, the VIS + NIR LED module was developed to combine a warm-white LED and pc-NIR LEDs. In order to feature out the availability of the VIS + NIR LED module against the TH lamp, they were used as the light source for evaluating the Soluble Solid Content (SSC) of an apple through VIS-NIR spectroscopy. The results show a remarkable feasibility in the performance of the partial least square (PLS) model using the VIS + NIR LED module; during PLS calibration, the correlation coefficient (R) values are 0.664 and 0.701, and the Mean Square Error (MSE) values are 0.681 and 0.602 for the TH lamp and VIS + NIR LED module, respectively. In VIS-NIR spectroscopy, this study indicates that the TH lamp could be replaceable with a warm-white LED and pc-NIR LEDs.

The Role of Negative Emotions Pre- and Post-Implementation of Graphic Health Warnings: Longitudinal Evidence from South Korea.

This longitudinal study investigated the factors that determine the effectiveness of graphic health warnings (GHWs) by comparing 246 South Korean smoker's responses before and after the introduction of the country's new tobacco control policy wherein GHWs were placed on all cigarette packaging. Even though introducing GHWs did not cause immediate changes in smokers' intention to quit smoking or perception of smoking's health risk, GHWs eventually motivated smokers to quit smoking when they experienced negative emotional responses to the newly introduced graphic warnings on cigarette packaging. More importantly, this study found that positive changes in smokers' perceived risk associated with smoking due to the introduction of GHWs mediated a positive relationship between changes in smokers' negative emotions (NE) from text-only warnings to graphic warnings and changes in their intention to quit smoking during the same period. Based on these results, the authors suggest that, for GHW policy to be more effective in motivating smoking cessation, the warnings need to convey images sufficiently unpleasant to induce negative emotional responses among smokers.

The Paradox of Smoking & Perceived Stress: Do Graphic Health Warnings Influence Smokers under High Stress in Adverse Ways?

The positive effects of graphic health warnings (GHWs) on quitting smoking have been widely demonstrated in the literature on cigarette warning. However, recent findings of smoker reactance to GHWs demand investigations of factors that may constrain the effects of GHWs. The current study sought to identify conditions in which GHWs do not have a positive impact on smokers' desire to quit with a focus on smokers' perceived stress. Two hundred and forty-four smokers in South Korea were exposed to either a text-only or a GHW cigarette pack in a between-subjects experiment. Results from this study suggest that the GHW condition is effective in increasing attention to the GHW, enhancing perceived usefulness of information, and desire to quit only among those with low (vs. high) perceived stress. In addition, an interaction effect between warning type and perceived stress on the desire to quit was sequentially mediated by attention and perceived information effectiveness. Based on the results, we suggest that GHWs were less effective for smokers with high levels of perceived stress because their stress appeared to exhaust the cognitive resources necessary to process the information.

The Moderating Effects of Self-Esteem and Self-Efficacy on Responses to Graphic Health Warnings on Cigarette Packages: A Comparison of Smokers and Nonsmokers.

Do graphic pictorial health warnings (GPHWs) on cigarette packaging work better for some people than others? According to the Extended Parallel Process Model (EPPM), fear appeals should heighten positive change only if a person believes he or she is capable of change (i.e., self-efficacy). We exposed 242 smokers and 241 nonsmokers (aged 18-29) in the Republic of Korea to either a GPHW or a text-only warning in a between-subjects experiment. Results indicated that the GPHW increased intentions and motivations to quit smoking (for smokers) and intentions and motivations to not start smoking (for nonsmokers). However, these effects were moderated by self-efficacy related to quitting or not starting smoking. For smokers, a GPHW was especially effective in increasing desires and intentions to quit for people high in self-efficacy and high in self-esteem. However, for nonsmokers, a GPHW was effective only when self-efficacy was high, regardless of self-esteem level. For smokers and nonsmokers, results were mediated by heightened perceived health estimation. Implications for understanding the effectiveness of warning labels on cigarettes, for the introduction of GPHWs in the Republic of Korea, and for the Extended Parallel Process Model, are discussed.

When sex doesn't sell to men: mortality salience, disgust and the appeal of products and advertisements featuring sexualized women.

Although men typically hold favorable views of advertisements featuring female sexuality, from a Terror Management Theory perspective, this should be less the case when thoughts of human mortality are salient. Two experiments conducted in South Korea supported this hypothesis across a variety of products (e.g., perfume and vodka). Men became more negative towards advertisements featuring female sexuality, and had reduced purchase intentions for those products, after thinking about their own mortality. Study 2 found that these effects were mediated by heightened disgust. Mortality thoughts did not impact women in either study. These findings uniquely demonstrate that thoughts of death interact with female sex-appeal to influence men's consumer choices, and that disgust mediates these processes. Implications for the role of emotion, and cultural differences, in terror management, for attitudes toward female sexuality, and for marketing strategies are discussed.