**1. Introduction**

Various methods of predicting and analyzing prices in the real estate market have been around since time immemorial. In the case of Joseon, 500 years ago, the biggest factor in determining land price was the crop harvest. Nowadays, however, the factors which determine the price of land can be confirmed to fluctuate due to various side points, such as the use value of the land, the area around the station, and the restricted area. As a result, there are various methods of predicting real estate prices [1,2], and in Korea, they are disclosed to citizens through land indexes.

In this paper, however, we will focus on history and policy. As in the past, the real estate market in the Republic of Korea is still going back and forth between hot and cold water like a roller coaster. In the Republic of Korea, large-scale apartment complexes were created by introducing large-scale residential complex construction in 1962 with the enforcement of the Korea Housing Corporation Act. At that time, Seoul was crowded with people who went to search for jobs across the country, and 80% of Seoul's population was concentrated in Gwanghwamun. Then, as the real estate prices surged, unlicensed buildings entered the scene, and houses became scarce.

Thus, the government promoted the construction of new residential areas or the transfer of administrative functions to the sub-Han River area, providing two alternatives.

**Citation:** Lee, S.-H.; Kim, J.-H.; Huh, J.-H. Land Price Forecasting Research by Macro and Micro Factors and Real Estate Market Utilization Plan Research by Landscape Factors: Big Data Analysis Approach. *Symmetry* **2021**, *13*, 616. https://doi.org/ 10.3390/sym13040616

Academic Editors: Edmundas Kazimieras Zavadskas, Jurgita Antucheviˇciene and Zenonas Turskis ˙

Received: 18 March 2021 Accepted: 1 April 2021 Published: 7 April 2021

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

The first option was to relocate the capital. Capital relocation involved dispersing the population by distributing administrative demand, which was concentrated in the central part of Seoul City. As it had only been about 10 years since the 6.25 war, Korea could not afford the astronomical costs and abandoned the first option. The second option was to develop the southern part of the Hangang River, particularly Yeongdeungpo, the subcenter of Seoul at the time. It was to be developed by incorporating the southern region into Seoul. At that time, the government formulated an economic development plan for an export-centric system, and sought the construction of national industrial parks in Ansan, Ulsan, Changwon, and Gwangyang. It needed a highway to connect with the national industrial complex and Seoul. The primary alternative was Yeongdeungpo, but it was not selected because of its high price and low site availability.

Thus, the southern part of the Han River was chosen, and Hannam Bridge in 1966 and Gyeongbu Expressway in 1968 were built to facilitate access. Through these two roads, Gangnam was designated as a migration land readjustment project area, and the development was started. In this plan, Yeongdong 1 and 2 earth were to be created; one area was the Gyeongbu Expressway project, and two areas were to have basic infrastructure built, while promoting the housing complex construction project in order to disperse the city center population. In 1972, Nonhyun-dong built public service apartments, apartment complexes, and detached houses. Nonetheless, the district, which used to be empty, was an area that was not of interest to people at the time, so the government shelved the development of Gangbuk and promoted Gangnam's development. As such, Gangbuk implemented large-scale regulatory policies, such as restrictions on the construction of certain facilities and public institutions, the prohibition of entertainment facilities, and the prohibition of the establishment of department stores and universities. In 1973, the Yeongdong district was designated as a development promotion district. With the waiving of property taxes, etc., the number of relocations to the Gangnam district increased; to date, Gangnam's representative apartments—Banpo Jugong Apartment and Apgujeong Hyundai Apartment—have been built and sold. In addition to residential complexes, adult entertainment establishments moved from Gangbuk to Gangnam, which benefitted from large-scale regulatory policies, thus making Gangnam a center of adult entertainment establishments. Moreover, on the transportation side, the construction of subway line 2 in 1975, Banpodaegyo Bridge, and the Namsan No. 3 tunnel in order to facilitate movement within the city center, along with the Gangnam Express Bus Terminal in 1976 were carried out. In terms of education, the prestigious high schools in downtown Gangbuk moved to the Gangnam area; public facilities and public enterprises in Gangnam moved to Jongno, the center of Seoul, but the gap was not as wide as it is now [3].

With low-rise apartments housing more than 5<sup>×</sup> <sup>10</sup><sup>4</sup> households rebuilt in the 21st century, Gangnam's land price skyrocketed. As such, Gangnam, which is still the wealthiest area in the Republic of Korea, has low supply, high demand, and many reconstruction targets. As mentioned above, Gangnam is currently the richest area with the best infrastructure. In the future real estate market, it would be desirable to introduce smart cities which can solve various problems in areas surrounded by landscape areas and areas subject to rebuilding, instead of unreasonable construction. Looking at of the history of the Gangnam real estate market from the 1960s to the present, we can see that the focus was on policy, but there are various factors in the real estate market in addition to policy. The prediction and analysis of land prices are extremely demanding.

Therefore, in this research, we will seek a method for predicting future land prices by combining macro and micro environment variables in the real estate market, in which it is difficult to predict land prices in the future. The target areas of the paper will be set in the six regional living areas in Gangnam-gu, Seoul, based on the apartments of 30 *tsubo* in each area. Furthermore, in the prefecture's research, we would like to use past data to confirm future data, but the current data is the data for 2019, using the data from 2015 to 2018, which has not been released yet. We want to check if it matches. Then, we would like to investigate whether some variables have the greatest effect on land prices using regression analysis [4],

and confirm that some variables and land prices are correlated through correlation analysis. In addition, in the real estate market, the factor of the landscape is also relevant, and we would like to investigate the relationship between real estate and landscape, which will be judged as a factor which will affect the future.

In order to confirm the relationship between the landscape and the real estate market, the effect of the landscape district on the real estate was investigated to find ways to interact. In order to explain the previous content again, we predicted land prices in the future by actively utilizing macroscopic and microscopic variables in real estate land price forecasting. We would like to use this method to improve the accuracy in the real estate market, which is difficult to predict, and we hope it will be useful in the future real estate market.
