Validity of the Korean Version of the Brief Irritability Test in Psychiatric Patients.

OBJECTIVE: This study aimed to investigate the validity and reliability of the Korean version of the Brief Irritability Test (BITe) and adapt it for Korean patients with psychiatric disorders. METHODS: A total of 296 patients at the Department of Psychiatry of Hanyang University Guri Hospital completed the BITe, Korean Beck Depression Inventory-II, Korean Beck Anxiety Inventory, the Korean version of the State-Trait Anger Expression Inventory, and Barratt Impulsiveness Scale-11. Construct validity was confirmed through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Reliability testing included assessments of internal consistency (Cronbach's α) and item-total correlations. Convergent validity was examined through correlational analyses with variables such as anxiety, depression, anger, and impulsivity. RESULTS: First, the scale had good internal consistency with a Cronbach's α of 0.88. Second, EFA indicated a single dimensionality of the BITe, and CFA demonstrated a reasonable fit for the single-factor model (comparative fit index=0.97, Tucker-Lewis Index=0.95, normed fit index=0.97, goodness-of-fit index=0.96, root mean square error of approximation=0.12, standardized root mean residual=0.03). Finally, the convergent validity analysis revealed a significant positive correlation with depression, anxiety, and anger, except for anger control, which is a sub-variable of anger. CONCLUSION: The results showed that the Korean version of the BITe had good psychometric properties, and might serve as a valuable tool for assessing irritability in Korean patients with psychiatric disorders.

Low-complexity nonlinear equalizer based on absolute operation for C-band IM/DD systems.

The intensity-modulation/direct-detection transmission system operating in the C-band suffers from nonlinear waveform distortions induced by fiber chromatic dispersion due to the square-law detection. The Volterra nonlinear equalizers (VNLEs) can be used at the receiver to compensate for such distortions. However, the major concern about the equalizers is their huge implementation complexity. In this paper, we propose and demonstrate a low-complexity nonlinear equalizer based on the absolute operation for a cost-sensitive IM/DD system. In this equalizer, the cross-beating product terms (required in VNLE) are replaced with the absolute operation of the sum of two input samples. We evaluate the performance of the proposed equalizer over a 56-Gb/s 4-ary pulse amplitude modulation transmission system implemented by using 1.5-µm directly modulated laser or electro-absorption modulated laser. The results show that the proposed equalizer performs similar to the 2nd-order diagonally-pruned VNLE, but lowers the implementation complexity by >20%. We also show that the proposed equalizer outperforms the VNLE when the implementation complexities of the two nonlinear equalizers are similar.