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When neutron survey metres are calibrated in neutron fields, the results for room- and air-scattered neutrons vary according to the distance from the source and the size, shape and construction of the neutron calibration room. ISO 8529-2 recommends four approaches for correcting these effects: the shadow-cone method, semi-empirical method, generalised fit method and reduced-fitting method. In this study, neutron scattering effects are evaluated and compared using the shadow-cone and semi-empirical methods for the neutron field of the Korea Atomic Energy Research Institute (KAERI). The neutron field is constructed using a 252Cf neutron source positioned in the centre of the neutron calibration room. To compare the neutron scattering effects using the two correction methods, measurements and simulations are performed using respectively KAERI's Bonner sphere spectrometer (BBS) and Monte Carlo N-Particle code at twenty different positions. Neutron spectra are measured by a europium-activated lithium iodide [6LiI(Eu)] scintillator in combination with the BBS. The calibration factors obtained using each methods show good agreement within 1.1%.

We examined sexual dimorphism in the craniodental traits of the raccoon dog Nyctereutes procyonoides from South Korea. Univariate comparisons of skull (cranium and mandible) and dental measurements revealed a small extent of sexual dimorphism in some measurements. The most indicative dimorphic measurements were the breadths of the upper and lower canines which were around 8% larger in male specimens on average. On the other hand, multivariate analyses using only skull traits showed slightly a clearer separation between sexes than those using only dental ones. This discrepancy may be derived from a higher variability in dental traits than in those of the skull. In conclusion, sexual dimorphism within N. procyonoides of South Korea is present, but was not so pronounced as for other local populations. However, measurements showing significant sexual dimorphism varied between different localities. This suggests that the selective forces acting upon craniodental morphology of each sex vary between populations of the species.