Kyuman Cho

A comparative study on hemicircular tibial plateau leveling osteotomy (hTPLO) and TPLO for correcting cranial cruciate ligament (CCL) ruptures at excessive tibial plateau angles (eTPAs) was performed with a specially fabricated hTPLO saw blade (hemicircular) and TPLO saw blade (quartercircular), respectively. Ten 3D-printed bone models with eTPAs (TPA > 40°), were resized to accommodate the respective saw blade shape for each method. Cranial closing wedge osteotomy (CCWO) combined with TPLO was also performed. Distances of segment rotation below the patellar tendon insertion (PTI) and differences between anatomical and mechanical axes after correction were measured. The TPAs of the bone models were 46.06 ± 4.40° (40.0–50.7°). Postoperative TPAs of hTPLO, TPLO, and TPLO combined with CCWO were 4.93 ± 1.025°, 4.52 ± 0.085°, and 4.17 ± 1.128°, respectively. Rotation distances from the PTI were 0.46 ± 2.153 mm, 8.67 ± 2.318 mm, and 1.13 ± 1.796 mm, respectively. hTPLO showed significantly less movement of the segment below the PTI than TPLO with or without CCWO (p < 0.01). Differences between anatomical and mechanical axes after hTPLO and TPLO with or without CCWO were 5.74 ± 2.231°, 6.43 ± 2.105°, and 5.16 ± 2.465°, respectively. Within the limitations of this model-based study, hTPLO demonstrated geometric feasibility for correction of excessive tibial plateau angles and was associated with less rotational displacement of the proximal tibial segment relative to the patellar tendon insertion than conventional TPLO and TPLO combined with CCWO. Further cadaveric, biomechanical, and clinical studies are required to evaluate its safety and clinical applicability.

An 11-month-old castrated male Pomeranian presented with nonunion following a femoral fracture that occurred after femoral head and neck osteotomy. Radiography and computed tomography revealed severe atrophy of the proximal bone fragment and retardation of the ipsilateral distal fragment and tibia. An autogenous bone graft using coccygeal bone was performed, in which three and a half coccyges were placed in succession and fixed using an orthogonal locking plate. To promote bone healing and facilitate proper weight bearing and ambulation, bone morphogenetic proteins, biphasic calcium phosphate, platelet-rich plasma, passive-range-of-motion exercises, transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, and low-level laser therapy were applied. During the four-year follow-up, it was observed that the previously engrafted bone healed well and maintained stability over a prolonged period, resulting in the patient being able to walk comfortably with good outcomes. However, some degree of lameness was noted in the dog when running owing to limb shortening and joint contracture.

An 11-month-old castrated male Pomeranian presented with nonunion following a femoral fracture that occurred after femoral head and neck osteotomy. Radiography and computed tomography revealed severe atrophy of the proximal bone fragment and retardation of the ipsilateral distal fragment and tibia. An autogenous bone graft using coccygeal bone was performed, in which three-and-a-half coccyges were placed in series and fixed using an orthogonal locking plate. To promote bone healing and facilitate proper weight bearing and ambulation, bone morphogenetic proteins, biphasic calcium phosphate, platelet-rich plasma, passive range of motion exercises, transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, and low level laser therapy were applied. During the four-year follow-up, it was observed that the previously engrafted bone healed well and maintained stability over a prolonged period, resulting in the patient being able to walk and trot comfortably with good outcomes. However, some degree of lameness was noted during galloping owing to limb shortening and joint contracture.

We present a new displacement probe for a gantry-type profilometer to measure the ground surface form. The system is based on heterodyne interferometry with an acousto-optic modulator (AOM) and I/Q demodulation scheme. When the light from the single-frequency laser diode passes through the AOM following the Bragg condition angle, it is divided into the non-diffracted zero-order and a diffracted first-order beam with a frequency shift as the amount of the AOM driving frequency. One beam is used for the test and the other for the reference beam. Orthogonally reflected beams pass through the AOM one more time, and these beams make a heterodyne signal with a double modulation frequency. In this case, the only backscattered beam from the ground surface satisfies the Bragg condition, producing the modulated interference. Therefore, the AOM tends to reduce the stray light noises from the other incidence angles, acting as a transmission filter for backscattered light. The interference light arrives at the high-speed photodiode and it is then demodulated using the I/Q demodulation to extract the phase value. Although the backscattered ray from the rough glass surface has a very low intensity, the I/Q interferometer can detect the signal because the phase can be acquired regardless of the intensity change. Preliminary experiments confirmed that the system can measure from backscattered light of ground glass surface form.

Several efforts have been made by many researchers to develop a model for schedule and cost integration in construction projects, but it is difficult to integrate and manage schedule and cost in an actual construction site using such a model. The integrated schedule and cost model developed in this study (1) enables the planning and control of repetitive construction processes and (2) can be used by a project manager in an actual construction site. Furthermore, an integrated schedule and cost model for the core wall construction, which is an important repetitive process in the recently booming high-rise building construction in terms of scheduling, was developed using the integration model developed in this study. It is expected that the integrated schedule and cost model developed can allow project managers to integrate the schedule and cost of repetitive construction processes more effectively and support the project managers’ decision-making.

An experimental study is conducted toward understanding the mechanism of nonlinear optical properties of PbTe thin film that were demonstrated potentially usable for nano-optical memory based on super-resolution technology. By way of a real time optical-electrical characterization of a PbTe thin film device, it is found that absorption coefficient decreases with increasing laser power, accompanied by increase in carrier concentration. From z-scan measurements, nonlinear optical coefficient due to a long pulse (1 μs) z-scan is found nearly 3 order of magnitude higher than the one due to a short pulse (30 ps) z-scan when input energy density is relatively comparable. Conceivably, these experimental findings call for a physical model that is able to account for the prevailing role of a thermal contribution within the framework of absorption saturation by band filling. We speculate that the absorption saturation might be enhanced dramatically by making various indirect interband transitions possible via participation of phonons in a photonic excitation process.