Speaking before a large crowd that was entertained by the rapper Psy of “Gangnam Style” fame on the lawn in front of the National Assembly, she urged North Korea to abandon its nuclear ambitions without delay, “instead of wasting its resources on nuclear and missile development and continuing to turn its back to the world in self-imposed isolation.”

Ms. Park invoked her father’s era, calling for a “second miracle on the Han River.” The first was the transformation under him of Seoul, the capital city, which straddles the river, from the rubble of the 1950-53 Korean War into an industrialized metropolis. He nurtured a handful of family controlled companies, such as Samsung and Hyundai, as engines of an export-driven economy. These companies have grown into globally recognized conglomerates.

Now, decades later, his daughter vowed to bring South Korea’s slowing economy “rejuvenation” and “revival,” terms favored under her father. But she nodded to the biggest complaints of ordinary South Koreans — widening economic inequality and the conglomerates’ overpowering expansion at the cost of smaller businesses — grievances, saying the second Han River miracle should be based on “economic democratization.”

Ms. Park promised to end unfair practices by big businesses and strengthen small and medium-sized enterprises so that “such businesses can prosper alongside large companies.”

Ms. Park’s father was assassinated by his own disgruntled spy chief in October 1979 and her mother by a pro-North Korean gunman four years earlier. In this slight, unmarried woman, South Koreans found the enormously appealing image of a loyal daughter focused on rebuilding her family’s reputation. She bears a remarkable resemblance to her father and echoes his themes, including her tireless references to “national defense.”

“She was born to be a conservative and security-minded,” said Jo Dong-ho, a professor at Ewha Womans University in Seoul, who cited a well-known episode about Ms. Park. “As a young woman, when she first heard of her father’s assassination, she did not cry or ask how he died, but rather the first thing she did was to ask whether everything was all right along the border with North Korea.”

Her presidency adds a family rivalry into relations between the two Koreas. Under her father, a staunchly anti-Communist conservative mainstream took root in South Korea. The current North Korean leader is Kim Jong-un, the grandson of Kim Il-sung, the North Korean founder, who sent 31 commandos in 1968 in a failed attempt to attack the Blue House and kill Ms. Park’s father.