Polysomnography is the standard method to score the sleep stages or to determine the quality of sleep. During all night examination, subjects must attach complicate and numerous electrodes on their body to acquire the biosignals. They can influence participants' sleep stage transition or sleep pattern, and the method seems intricate. In many researches, it is reported that autonomic nervous system (ANS) is varying with sleep stage transition and heart rate variability (HRV) is one of the indices which reflects the changes of autonomic nervous system. In this point of view, we can estimate the sleep quality by observing the HRV variation. In this study, to analyze the heart rate variability, we introduce a new system that can detect the heart beats of subjects during sleep by using bed installed load-cell sensors. The pressure to the sensor changes with the pulsation of the heart and we consider it as ballistocardiogram, the physical heart beat signal. To validate our system, we adopted this system for the 4 subjects with the polysomnography. The results show the LF/HF ratio of the heart rate, one of the reflection parameters of ANS, acquired from the system for each sleep stage. To validate the results, the HRV from electrocardiogram using Ag-AgCl electrodes will be compared.

Polysomnagraphy, the method evaluating the sleep quality, is the reliable and standard method. However, to perform it, subject has to attach many sensors to their body. It seems intrusive, tangled and interrupting the subjects sleep. For the sake of monitoring the daily sleep pattern, simple method measuring the biosignal nonintrusively is needed. At that point, respiration is a beneficial signal, because it can be easily acquired by check the change of the thorax or abdomen. Respiration is one of the representatives of the reflection of the autonomic nervous system. According to the transition of the sleep stages, autonomic nervous system also changes and it can be shown by respiration.In this study, REM and non-REM sleep is classified by only using respiration for the 3 subjects. To enhance the performance, activity signal acquired by load-cell installed bed is added to divide the wake and REM sleep. At the results, hypnograms with polysomnagraphic data is compared with them. It can be seen that high correlation between the REM sleep and increasing pattern of the respiration rates.

Ran-Ju Jung et al. Reply:In the preceding Comment [1] on our recent Letter [2], Kucherenko et al. claimed that our conclusions on the localized character of f states in strongly -like Ce compounds are not convincing since cross-section and final-state effects were not properly taken into account. They mentioned that itinerant 4f contributions should be subtracted from the calculated density of f states (f-DOS) for a comparison with resonant photoemission (RPE) spectra because these itinerant states are not enhanced by the RPE process. We agree that such difference of resonance enhancement exists depending on the degree of localization, but we believe this effect is not big enough to change our main conclusion. Looking at Fig. 1 in the Comment [1], we can see that the experimental results are still not well reproduced by this subtraction procedure (hatched curves). The discrepancies between theory and experiment become weaker, but are still strong enough to imply the ''localized'' picture is a better starting point. And the fact that the subtractions affect only weakly the features close to the Fermi energy where the ''localized'' picture and ''itinerant'' picture make main discrepancies implies that our approach [2] describes the main aspects of this problem. As for our remark that CeRh 2 is closer to itinerancy than CeRh 3 , it is only in the sense that DOS fitting with self-energy corrections gives better agreement in CeRh 2 . We do not dispute the importance of the hybridization between Ce 4f state and the d states of transition-metal elements in these extremely -like compounds, as stated clearly in the Introduction (third paragraph) of our Letter [2]. And we also found that the hybridization of 4f and valence band states is stronger for CeRh 3 than for CeRh 2 from our Anderson impurity model fitting, in agreement with the band-calculation results of the Comment. Since there is no unique measure of ''itinerancy,'' we suppose there is no real physical significance to determine which is closer to the itinerancy.Kucherenko et al. also proposed that further aspects like final-state effects due to the specific geometry of the experiment should be considered for a proper comparison of the calculated f-DOS with RPE data. For this point, we have discussed the photon energy dependence of 3d ! 4f RPE spectra in another publication [3]. And considering that our RPE data were taken from scraped polycrystalline samples [2], we believe the specific geometry of the ex-3