PURPOSE: This study aimed to identify the best way of developing equivalent item sets and to propose a stable and effective managementplan for periodical licensing examinations. METHODS: Five pre-equated item sets were developed based on the predicted correct answer rate of each item using linear programming. These pre-equated item sets were compared to the ones that were developed with a random item selection method based on the actual correct answer rate (ACAR) and difficulty from item response theory (IRT). The results with and without common items were also compared in the same way. ACAR and the IRT difficulty were used to determine whether there was a significant difference between the pre-equating conditions. RESULTS: There was a statistically significant difference in IRT difficulty among the results from different pre-equated conditions. The predicted correct answer rate was divided using 2 or 3 difficulty categories, and the ACAR and IRT difficulty parameters of the 5 item sets were equally constructed. Comparing the item set conditions with and without common items, including common items did not make a significant contribution to the equating of the 5 item sets. CONCLUSION This study suggested that the linear programming method is applicable to construct equated-item sets that reflect each content area. The suggested best method to construct equated item sets is to divide the predicted correct answer rate using 2 or 3 difficulty categories, regardless of common items. If pre-equated item sets are required to construct a test based on the actual data, several methods should be considered by simulation studies to determine which is optimal before administering a real test.

PURPOSE: This study aimed to identify the best way of developing equivalent item sets and to propose a stable and effective management plan for periodical licensing examinations. METHODS: Five pre-equated item sets were developed based on the predicted correct answer rate of each item using linear programming. These pre-equated item sets were compared to the ones that were developed with a random item selection method based on the actual correct answer rate (ACAR) and difficulty from item response theory (IRT). The results with and without common items were also compared in the same way. ACAR and the IRT difficulty were used to determine whether there was a significant difference between the pre-equating conditions. RESULTS: There was a statistically significant difference in IRT difficulty among the results from different pre-equated conditions. The predicted correct answer rate was divided using 2 or 3 difficulty categories, and the ACAR and IRT difficulty parameters of the 5 item sets were equally constructed. Comparing the item set conditions with and without common items, including common items did not make a significant contribution to the equating of the 5 item sets. CONCLUSION: This study suggested that the linear programming method is applicable to construct equated-item sets that reflect each content area. The suggested best method to construct equated item sets is to divide the predicted correct answer rate using 2 or 3 difficulty categories, regardless of common items. If pre-equated item sets are required to construct a test based on the actual data, several methods should be considered by simulation studies to determine which is optimal before administering a real test.
Licensure ; Methods ; Programming, Linear

BACKGROUND: Paroxysmal atrial fibrillation (PAF) causes not only severe symptoms and hemodynamic changes, but may progress to chronic atrial fibrillation. Autonomic nervous system or atrial premature beat (APB) has been suggested to contribute to the spontaneous initiation of PAF, but the exact mechanism has been largely unknown. METHODS: One hundred and twenty nine episodes of PAF lasting longer than 5 sec were analyzed in 18 patients (M:F=11:?). Two minutes of normal sinus rhythm before the onset of PAF, and the initial one minute of PAF were printed and analyzed. RESULTS: Most of PAFs were initiated by APBs (38%) or rapid atrial tachycardias (AT, 59%). The frequency of APBs tended to increase immediately before PAF onset (p=0.08). The coupling intervals and coupling indices were not significantly different between PAF-producing APBs and benign APBs. More than half of PAF episodes were initiated by rapid ATs (rate, 357+/-50 bpm). After the onset, they accelerated over several seconds and then degenerated into AF. In some cases, transition from AF to atrial flutter and vice versa were observed. Heart rate, measured at 60-second intervals during 2 minutes before PAF onset, did not change significantly (p=0.44). CONCLUSION: Most of PAFs were initiated by APBs or rapid ATs. Heart rate did not change significantly but the frequency of APBs tended to increase immediately before PAF onset. Rapid ATs frequently accelerated and degenerated into AF. In this regard, Holter monitoring could be useful in identifying patients with PAF triggered by rapid ATs.
Atrial Fibrillation* ; Atrial Flutter ; Autonomic Nervous System ; Cardiac Complexes, Premature ; Electrocardiography, Ambulatory* ; Heart Rate ; Hemodynamics ; Humans ; Tachycardia

We analyzed the genetic diversity of Cylindrocarpon destructans isolates obtained from Korean ginseng (i.e., Panax ginseng) roots by performing virulence tests and nuclear ribosomal gene internal transcribed spacer (ITS) and mitochondrial small subunit (mt SSU) rDNA sequence analysis. The phylogenetic relationship analysis performed using ITS DNA sequences and isolates from other hosts helped confirm that all the Korean C. destructans isolates belonged to Nectria/Neonectria radicicola complex. The results of in vivo and ex vivo virulence tests showed that the C. destructans isolates could be divided into two groups according to their distinctive difference in virulence and the genetic diversity. The highly virulent Korean isolates in pathogenicity group II (PG II), together with foreign isolates from P. ginseng and P. quinquefolius, formed a single group. The weakly virulent isolates in pathogenicity group I, together with the foreign isolates from other host plants, formed another group and exhibited a greater genetic diversity than the isolates of PG II, as confirmed by the mt SSU rDNA sequence analysis. In addition, as the weakly virulent Korean isolates were genetically very similar to the foreign isolates from other hosts, they were likely to originate from hosts other than the ginseng plants.
Base Sequence ; DNA, Ribosomal ; Genetic Variation* ; Panax* ; Sequence Analysis ; Virulence*

The spontaneous perforation of sinus of Valsalva without congenital anomaly such as aneurysm and trauma has not been reported. We report a 66-year-old female presenting with ST elevation myocardial infarction due to compressing the proximal part of right coronary artery by hematoma attributed to spontaneous perforation of sinus of Vaslava. The patient was stabilized after surgical primary repair.
Aged ; Aneurysm ; Coronary Vessels ; Female ; Hematoma ; Humans ; Myocardial Infarction ; Sinus of Valsalva